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6<title>C++ Standard Library Active Issues List</title>
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22<table>
23<tbody><tr>
24<td align="left">Doc. no.</td>
25<td align="left">N3011=09-0201</td>
26</tr>
27<tr>
28<td align="left">Date:</td>
29<td align="left">2009-11-08</td>
30</tr>
31<tr>
32<td align="left">Project:</td>
33<td align="left">Programming Language C++</td>
34</tr>
35<tr>
36<td align="left">Reply to:</td>
37<td align="left">Howard Hinnant &lt;<a href="mailto:howard.hinnant@gmail.com">howard.hinnant@gmail.com</a>&gt;</td>
38</tr>
39</tbody></table>
40<h1>C++ Standard Library Active Issues List (Revision R68)</h1>
41
42  <p>Reference ISO/IEC IS 14882:2003(E)</p>
43  <p>Also see:</p>
44  <ul>
45      <li><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-toc.html">Table of Contents</a> for all library issues.</li>
46      <li><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html">Index by Section</a> for all library issues.</li>
47      <li><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html">Index by Status</a> for all library issues.</li>
48      <li><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html">Library Defect Reports List</a></li>
49      <li><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html">Library Closed Issues List</a></li>
50  </ul>
51  <p>The purpose of this document is to record the status of issues
52  which have come before the Library Working Group (LWG) of the ANSI
53  (J16) and ISO (WG21) C++ Standards Committee. Issues represent
54  potential defects in the ISO/IEC IS 14882:2003(E) document.  
55  </p>
56
57  <p>This document contains only library issues which are actively being
58  considered by the Library Working Group, i.e., issues which have a
59  status of <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>, 
60  <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>, or <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Review">Review</a>. See
61  <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html">Library Defect Reports List</a> for issues considered defects and 
62  <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html">Library Closed Issues List</a> for issues considered closed.</p>
63
64  <p>The issues in these lists are not necessarily formal ISO Defect
65  Reports (DR's). While some issues will eventually be elevated to
66  official Defect Report status, other issues will be disposed of in
67  other ways. See <a href="#Status">Issue Status</a>.</p>
68
69  <p>Prior to Revision 14, library issues lists existed in two slightly
70  different versions; a Committee Version and a Public
71  Version. Beginning with Revision 14 the two versions were combined
72  into a single version.</p>
73
74  <p>This document includes <i>[bracketed italicized notes]</i> as a
75  reminder to the LWG of current progress on issues. Such notes are
76  strictly unofficial and should be read with caution as they may be
77  incomplete or incorrect. Be aware that LWG support for a particular
78  resolution can quickly change if new viewpoints or killer examples are
79  presented in subsequent discussions.</p>
80
81  <p>For the most current official version of this document see 
82  <a href="http://www.open-std.org/jtc1/sc22/wg21/">http://www.open-std.org/jtc1/sc22/wg21/</a>.
83  Requests for further information about this document should include
84  the document number above, reference ISO/IEC 14882:2003(E), and be
85  submitted to Information Technology Industry Council (ITI), 1250 Eye
86  Street NW, Washington, DC 20005.</p>
87
88  <p>Public information as to how to obtain a copy of the C++ Standard,
89  join the standards committee, submit an issue, or comment on an issue
90  can be found in the comp.std.c++ FAQ.
91  </p>
92
93<p><a name="submit_issue"></a><b>How to submit an issue</b></p>
94
95<ol type="A">
96<a name="submit_issue_A"></a><li>
97Mail your issue to the author of this list.
98</li>
99<a name="submit_issue_B"></a><li>
100Specify a short descriptive title.  If you fail to do so, the subject line of your
101mail will be used as the issue title.
102</li>
103<a name="submit_issue_C"></a><li>
104If the "From" on your email is not the name you wish to appear as issue submitter,
105then specify issue submitter.
106</li>
107<a name="submit_issue_D"></a><li>
108Provide a brief discussion of the problem you wish to correct.  Refer to the latest
109working draft or standard using [section.tag] and paragraph numbers where appropriate.
110</li>
111<a name="submit_issue_E"></a><li>
112Provide proposed wording.  This should indicate exactly how you want the standard
113to be changed.  General solution statements belong in the discussion area.  This
114area contains very clear and specific directions on how to modify the current
115draft.  If you are not sure how to word a solution, you may omit this part.
116But your chances of a successful issue greatly increase if you attempt wording.
117</li>
118<a name="submit_issue_F"></a><li>
119It is not necessary for you to use html markup.  However, if you want to, you can
120&lt;ins&gt;<ins>insert text like this</ins>&lt;/ins&gt; and &lt;del&gt;<del>delete text like
121this</del>&lt;/del&gt;.  The only strict requirement is to communicate clearly to
122the list maintainer exactly how you want your issue to look.
123</li>
124<a name="submit_issue_G"></a><li>
125It is not necessary for you to specify other html font/formatting
126mark-up, but if you do the list maintainer will attempt to respect your
127formatting wishes (as described by html markup, or other common idioms).
128</li>
129<a name="submit_issue_H"></a><li>
130It is not necessary for you to specify open date or last modified date (the date
131of your mail will be used).
132</li>
133<a name="submit_issue_I"></a><li>
134It is not necessary for you to cross reference other issues, but you can if you
135like.  You do not need to form the hyperlinks when you do, the list maintainer will
136take care of that.
137</li>
138<a name="submit_issue_J"></a><li>
139One issue per email is best.
140</li>
141<a name="submit_issue_K"></a><li>
142Between the time you submit the issue, and the next mailing deadline
143(date at the top of the Revision History), you <em>own</em> this issue. 
144You control the content, the stuff that is right, the stuff that is
145wrong, the format, the misspellings, etc.  You can even make the issue
146disappear if you want.  Just let the list maintainer know how you want
147it to look, and he will try his best to accommodate you.  After the
148issue appears in an official mailing, you no longer enjoy exclusive
149ownership of it.
150</li>
151</ol>
152
153
154<h2>Revision History</h2>
155<ul>
156<li>R68: 
1572009-11-06 post-Santa Cruz mailing.
158<ul>
159<li><b>Summary:</b><ul>
160<li>205 open issues, down by 77.</li>
161<li>1055 closed issues, up by 120.</li>
162<li>1260 issues total, up by 43.</li>
163</ul></li>
164<li><b>Details:</b><ul>
165<li>Added the following Dup issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1230">1230</a>.</li>
166<li>Added the following NAD issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1229">1229</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1236">1236</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1243">1243</a>.</li>
167<li>Added the following NAD Editorial issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1232">1232</a>.</li>
168<li>Added the following NAD Future issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1235">1235</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1242">1242</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1248">1248</a>.</li>
169<li>Added the following New issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1218">1218</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1219">1219</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1221">1221</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1222">1222</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1223">1223</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1224">1224</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1225">1225</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1234">1234</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1240">1240</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1244">1244</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1245">1245</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1246">1246</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1249">1249</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1250">1250</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1251">1251</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1252">1252</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1253">1253</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1254">1254</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1255">1255</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1256">1256</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1257">1257</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1258">1258</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1259">1259</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1260">1260</a>.</li>
170<li>Added the following Open issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1228">1228</a>.</li>
171<li>Added the following Ready issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1227">1227</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1237">1237</a>.</li>
172<li>Added the following Review issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1247">1247</a>.</li>
173<li>Added the following Tentatively NAD Editorial issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1233">1233</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1239">1239</a>.</li>
174<li>Added the following Tentatively NAD Future issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1238">1238</a>.</li>
175<li>Added the following Tentatively Ready issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1220">1220</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1226">1226</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1231">1231</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1241">1241</a>.</li>
176<li>Changed the following issues from New to NAD: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1132">1132</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1148">1148</a>.</li>
177<li>Changed the following issues from Open to NAD: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#96">96</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#458">458</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#463">463</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#916">916</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#917">917</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#919">919</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#955">955</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#977">977</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1009">1009</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1020">1020</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1035">1035</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1042">1042</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1051">1051</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1064">1064</a>.</li>
178<li>Changed the following issues from Review to NAD: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#668">668</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#930">930</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1091">1091</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1102">1102</a>.</li>
179<li>Changed the following issues from Tentatively NAD to NAD: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#588">588</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#617">617</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#971">971</a>.</li>
180<li>Changed the following issues from Tentatively NAD Future to NAD: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1062">1062</a>.</li>
181<li>Changed the following issues from NAD Concepts to NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1143">1143</a>.</li>
182<li>Changed the following issues from New to NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1116">1116</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1117">1117</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1122">1122</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1129">1129</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1145">1145</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1146">1146</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1147">1147</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1155">1155</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1166">1166</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1172">1172</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1174">1174</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1179">1179</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1195">1195</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1196">1196</a>.</li>
183<li>Changed the following issues from Open to NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#431">431</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#580">580</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#635">635</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#719">719</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#823">823</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#827">827</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#879">879</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#880">880</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#908">908</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#923">923</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#924">924</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#926">926</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#944">944</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#947">947</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#958">958</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1046">1046</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1048">1048</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1054">1054</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1055">1055</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1075">1075</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1088">1088</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1160">1160</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1161">1161</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1162">1162</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1163">1163</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1165">1165</a>.</li>
184<li>Changed the following issues from Review to NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#828">828</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#897">897</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#976">976</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1043">1043</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1047">1047</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1049">1049</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1050">1050</a>.</li>
185<li>Changed the following issues from New to NAD Future: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1120">1120</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1150">1150</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1184">1184</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1203">1203</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1217">1217</a>.</li>
186<li>Changed the following issues from Open to NAD Future: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#484">484</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#532">532</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#851">851</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#933">933</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#935">935</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#936">936</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#961">961</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1041">1041</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1053">1053</a>.</li>
187<li>Changed the following issues from Tentatively NAD Future to NAD Future: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1031">1031</a>.</li>
188<li>Changed the following issues from New to Open: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1118">1118</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1119">1119</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1151">1151</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1153">1153</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1156">1156</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1171">1171</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1173">1173</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1183">1183</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1191">1191</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1211">1211</a>.</li>
189<li>Changed the following issues from Ready to Open: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#430">430</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#834">834</a>.</li>
190<li>Changed the following issues from Review to Open: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#397">397</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#408">408</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#835">835</a>.</li>
191<li>Changed the following issues from Tentatively NAD to Open: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#625">625</a>.</li>
192<li>Changed the following issues from New to Ready: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1123">1123</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1134">1134</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1135">1135</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1136">1136</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1144">1144</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1177">1177</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1194">1194</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1204">1204</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1216">1216</a>.</li>
193<li>Changed the following issues from Open to Ready: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#296">296</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#471">471</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#485">485</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#539">539</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#816">816</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#860">860</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#865">865</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#872">872</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#920">920</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#932">932</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#939">939</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#940">940</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#960">960</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#963">963</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#974">974</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#978">978</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1011">1011</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1030">1030</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1079">1079</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1098">1098</a>.</li>
194<li>Changed the following issues from Review to Ready: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#473">473</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#671">671</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#836">836</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#854">854</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#868">868</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#871">871</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#889">889</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#893">893</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#921">921</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#950">950</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#954">954</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#957">957</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#962">962</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#967">967</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#968">968</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#983">983</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1052">1052</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1094">1094</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1095">1095</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1097">1097</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1100">1100</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1104">1104</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1157">1157</a>.</li>
195<li>Changed the following issues from New to Review: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1130">1130</a>.</li>
196<li>Changed the following issues from Open to Review: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#556">556</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#631">631</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#676">676</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#727">727</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#929">929</a>.</li>
197<li>Changed the following issues from Open to Tentatively NAD: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1056">1056</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1099">1099</a>.</li>
198<li>Changed the following issues from New to Tentatively NAD Concepts: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1186">1186</a>.</li>
199<li>Changed the following issues from New to Tentatively NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1115">1115</a>.</li>
200<li>Changed the following issues from New to Tentatively NAD Future: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1121">1121</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1201">1201</a>.</li>
201<li>Changed the following issues from Open to Tentatively NAD Future: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1112">1112</a>.</li>
202<li>Changed the following issues from New to Tentatively Ready: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1126">1126</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1138">1138</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1152">1152</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1158">1158</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1189">1189</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1192">1192</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1208">1208</a>.</li>
203<li>Changed the following issues from Open to Tentatively Ready: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#987">987</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#999">999</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1071">1071</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1090">1090</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1108">1108</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1113">1113</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1114">1114</a>.</li>
204<li>Changed the following issues from Ready to WP: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#149">149</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#419">419</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#498">498</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#564">564</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#565">565</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#630">630</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#659">659</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#696">696</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#711">711</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#716">716</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#723">723</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#788">788</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#822">822</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#838">838</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#847">847</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#857">857</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#859">859</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#876">876</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#881">881</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#883">883</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#886">886</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#934">934</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1004">1004</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1178">1178</a>.</li>
205<li>Changed the following issues from Tentatively Ready to WP: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1012">1012</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1019">1019</a>.</li>
206</ul></li>
207</ul>
208</li>
209<li>R67: 
2102009-09-25 pre-Santa Cruz mailing.
211<ul>
212<li><b>Summary:</b><ul>
213<li>282 open issues, up by 32.</li>
214<li>935 closed issues, down by 1.</li>
215<li>1217 issues total, up by 31.</li>
216</ul></li>
217<li><b>Details:</b><ul>
218<li>Added the following New issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1187">1187</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1188">1188</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1189">1189</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1190">1190</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1191">1191</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1192">1192</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1193">1193</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1194">1194</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1195">1195</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1196">1196</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1197">1197</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1198">1198</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1199">1199</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1200">1200</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1201">1201</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1202">1202</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1203">1203</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1204">1204</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1205">1205</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1206">1206</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1207">1207</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1208">1208</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1209">1209</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1210">1210</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1211">1211</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1212">1212</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1213">1213</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1214">1214</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1215">1215</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1216">1216</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1217">1217</a>.</li>
219<li>Changed the following issues from NAD to Open: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#296">296</a>.</li>
220<li>Changed the following issues from WP to Pending WP: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#970">970</a>.</li>
221<li>Changed the following issues from Open to Review: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#976">976</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1052">1052</a>.</li>
222<li>Changed the following issues from Ready to Review: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#780">780</a>.</li>
223</ul></li>
224</ul>
225</li>
226<li>R66: 
2272009-07-31 post-Frankfurt mailing.
228<ul>
229<li><b>Summary:</b><ul>
230<li>250 open issues, down by 128.</li>
231<li>936 closed issues, up by 171.</li>
232<li>1186 issues total, up by 43.</li>
233</ul></li>
234<li><b>Details:</b><ul>
235<li>Added the following NAD issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1164">1164</a>.</li>
236<li>Added the following NAD Concepts issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1149">1149</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1167">1167</a>.</li>
237<li>Added the following NAD Editorial issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1168">1168</a>.</li>
238<li>Added the following New issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1144">1144</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1145">1145</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1146">1146</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1147">1147</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1148">1148</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1150">1150</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1151">1151</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1152">1152</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1153">1153</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1154">1154</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1155">1155</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1156">1156</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1158">1158</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1159">1159</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1166">1166</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1169">1169</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1170">1170</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1171">1171</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1172">1172</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1173">1173</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1174">1174</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1175">1175</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1176">1176</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1177">1177</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1179">1179</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1180">1180</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1181">1181</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1182">1182</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1183">1183</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1184">1184</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1185">1185</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1186">1186</a>.</li>
239<li>Added the following Open issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1160">1160</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1161">1161</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1162">1162</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1163">1163</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1165">1165</a>.</li>
240<li>Added the following Ready issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1178">1178</a>.</li>
241<li>Added the following Review issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1157">1157</a>.</li>
242<li>Changed the following issues from Open to Dup: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#750">750</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#895">895</a>.</li>
243<li>Changed the following issues from Open to NAD: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#111">111</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#128">128</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#138">138</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#190">190</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#219">219</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#290">290</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#309">309</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#342">342</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#343">343</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#382">382</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#394">394</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#398">398</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#417">417</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#418">418</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#421">421</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#459">459</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#466">466</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#492">492</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#502">502</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#503">503</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#546">546</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#573">573</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#582">582</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#585">585</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#597">597</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#606">606</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#614">614</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#632">632</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#721">721</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#747">747</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#751">751</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#833">833</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#941">941</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#992">992</a>.</li>
244<li>Changed the following issues from Review to NAD: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1003">1003</a>.</li>
245<li>Changed the following issues from Tentatively NAD to NAD: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#568">568</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#644">644</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#667">667</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#669">669</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#701">701</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#702">702</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#785">785</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#863">863</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#901">901</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#903">903</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#946">946</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#988">988</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#995">995</a>.</li>
246<li>Changed the following issues from Tentatively Ready to NAD: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1002">1002</a>.</li>
247<li>Changed the following issues from New to NAD Concepts: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1124">1124</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1127">1127</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1128">1128</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1139">1139</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1140">1140</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1141">1141</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1142">1142</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1143">1143</a>.</li>
248<li>Changed the following issues from Open to NAD Concepts: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#902">902</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#989">989</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1000">1000</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1007">1007</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1010">1010</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1015">1015</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1016">1016</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1017">1017</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1018">1018</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1026">1026</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1027">1027</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1028">1028</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1029">1029</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1032">1032</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1036">1036</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1057">1057</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1059">1059</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1072">1072</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1078">1078</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1081">1081</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1082">1082</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1083">1083</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1084">1084</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1085">1085</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1086">1086</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1092">1092</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1096">1096</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1105">1105</a>.</li>
249<li>Changed the following issues from Review to NAD Concepts: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1001">1001</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1005">1005</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1080">1080</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1087">1087</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1111">1111</a>.</li>
250<li>Changed the following issues from Tentatively NAD to NAD Concepts: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#912">912</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#918">918</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1074">1074</a>.</li>
251<li>Changed the following issues from Tentatively NAD Editorial to NAD Concepts: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#927">927</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1109">1109</a>.</li>
252<li>Changed the following issues from Tentatively Ready to NAD Concepts: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#906">906</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#913">913</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#914">914</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#928">928</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1024">1024</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1063">1063</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1067">1067</a>.</li>
253<li>Changed the following issues from Open to NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#718">718</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#873">873</a>.</li>
254<li>Changed the following issues from Tentatively NAD Editorial to NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#424">424</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#825">825</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#830">830</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#837">837</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#862">862</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#867">867</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#884">884</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#945">945</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#952">952</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#969">969</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#972">972</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#973">973</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#979">979</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1023">1023</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1058">1058</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1060">1060</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1061">1061</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1077">1077</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1101">1101</a>.</li>
255<li>Changed the following issues from Tentatively Ready to NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1013">1013</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1107">1107</a>.</li>
256<li>Changed the following issues from Open to NAD Future: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#255">255</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#423">423</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#523">523</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#708">708</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#760">760</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#839">839</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#877">877</a>.</li>
257<li>Changed the following issues from CD1 to Open: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#823">823</a>.</li>
258<li>Changed the following issues from NAD Editorial to Open: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#299">299</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#484">484</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#532">532</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#556">556</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#594">594</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#631">631</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#676">676</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#704">704</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#724">724</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#742">742</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#811">811</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#870">870</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#872">872</a>.</li>
259<li>Changed the following issues from Review to Open: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#879">879</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#919">919</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#929">929</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#939">939</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#987">987</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1009">1009</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1093">1093</a>.</li>
260<li>Changed the following issues from Tentatively NAD to Open: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#458">458</a>.</li>
261<li>Changed the following issues from Tentatively NAD Future to Open: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#96">96</a>.</li>
262<li>Changed the following issues from Tentatively Ready to Open: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#910">910</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#915">915</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#932">932</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#940">940</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#974">974</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#976">976</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#999">999</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1011">1011</a>.</li>
263<li>Changed the following issues from Open to Ready: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#149">149</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#419">419</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#430">430</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#498">498</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#564">564</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#565">565</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#630">630</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#659">659</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#696">696</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#711">711</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#716">716</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#723">723</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#788">788</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#834">834</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#838">838</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#847">847</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#857">857</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#859">859</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#876">876</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#881">881</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#883">883</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#886">886</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1004">1004</a>.</li>
264<li>Changed the following issues from Review to Ready: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#780">780</a>.</li>
265<li>Changed the following issues from Tentatively NAD to Ready: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#822">822</a>.</li>
266<li>Changed the following issues from Tentatively Ready to Ready: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#934">934</a>.</li>
267<li>Changed the following issues from NAD to Review: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#871">871</a>.</li>
268<li>Changed the following issues from Open to Review: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#397">397</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#408">408</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#473">473</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#671">671</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#836">836</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#868">868</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#889">889</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#893">893</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#930">930</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#954">954</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#962">962</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#967">967</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#968">968</a>.</li>
269<li>Changed the following issues from Tentatively NAD to Review: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#668">668</a>.</li>
270<li>Changed the following issues from Tentatively Ready to Review: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#950">950</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1100">1100</a>.</li>
271<li>Changed the following issues from Open to Tentatively NAD: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#588">588</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#617">617</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#625">625</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#971">971</a>.</li>
272<li>Changed the following issues from Open to Tentatively NAD Future: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1031">1031</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1062">1062</a>.</li>
273<li>Changed the following issues from Open to Tentatively Ready: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1012">1012</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1019">1019</a>.</li>
274<li>Changed the following issues from Tentatively Ready to WP: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#688">688</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#765">765</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#810">810</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#814">814</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#853">853</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#869">869</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#878">878</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#888">888</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#890">890</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#898">898</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#899">899</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#904">904</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#907">907</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#909">909</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#922">922</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#925">925</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#931">931</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#938">938</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#943">943</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#948">948</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#949">949</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#965">965</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#970">970</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#975">975</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#981">981</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#982">982</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#984">984</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#986">986</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#990">990</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#991">991</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#993">993</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#994">994</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#997">997</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#998">998</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1006">1006</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1014">1014</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1021">1021</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1037">1037</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1038">1038</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1039">1039</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1040">1040</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1044">1044</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1045">1045</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1065">1065</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1066">1066</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1070">1070</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1073">1073</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1103">1103</a>.</li>
275</ul></li>
276</ul>
277</li>
278<li>R65: 
2792009-06-19 pre-Frankfurt mailing.
280<ul>
281<li><b>Summary:</b><ul>
282<li>378 open issues, up by 32.</li>
283<li>765 closed issues, up by 0.</li>
284<li>1143 issues total, up by 32.</li>
285</ul></li>
286<li><b>Details:</b><ul>
287<li>Added the following New issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1115">1115</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1116">1116</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1117">1117</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1118">1118</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1119">1119</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1120">1120</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1121">1121</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1122">1122</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1123">1123</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1124">1124</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1125">1125</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1126">1126</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1127">1127</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1128">1128</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1129">1129</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1130">1130</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1131">1131</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1132">1132</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1133">1133</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1134">1134</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1135">1135</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1136">1136</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1137">1137</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1138">1138</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1139">1139</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1140">1140</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1141">1141</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1142">1142</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1143">1143</a>.</li>
288<li>Added the following Open issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1112">1112</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1113">1113</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1114">1114</a>.</li>
289<li>Changed the following issues from Pending NAD Editorial to NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#937">937</a>.</li>
290<li>Changed the following issues from New to Open: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#696">696</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#716">716</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#727">727</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#865">865</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#900">900</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#911">911</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#916">916</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#917">917</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#920">920</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#933">933</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#935">935</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#941">941</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#947">947</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#951">951</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#953">953</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#954">954</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#955">955</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#956">956</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#977">977</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#978">978</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#985">985</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#989">989</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#996">996</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1033">1033</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1054">1054</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1056">1056</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1057">1057</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1059">1059</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1062">1062</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1068">1068</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1069">1069</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1071">1071</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1072">1072</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1076">1076</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1090">1090</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1092">1092</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1096">1096</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1098">1098</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1099">1099</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1105">1105</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1106">1106</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1108">1108</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1110">1110</a>.</li>
291<li>Changed the following issues from Review to Open: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#817">817</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#971">971</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#992">992</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1004">1004</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1010">1010</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1012">1012</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1015">1015</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1019">1019</a>.</li>
292<li>Changed the following issues from New to Review: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#780">780</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#835">835</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#897">897</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#919">919</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#939">939</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#957">957</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#983">983</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1001">1001</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1080">1080</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1091">1091</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1093">1093</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1094">1094</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1095">1095</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1097">1097</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1102">1102</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1104">1104</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1111">1111</a>.</li>
293<li>Changed the following issues from Open to Review: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#921">921</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#987">987</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1087">1087</a>.</li>
294<li>Changed the following issues from New to Tentatively NAD: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#568">568</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#701">701</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#702">702</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#785">785</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#863">863</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#903">903</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#912">912</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#918">918</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#946">946</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#995">995</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1074">1074</a>.</li>
295<li>Changed the following issues from Open to Tentatively NAD: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#458">458</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#644">644</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#667">667</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#668">668</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#669">669</a>.</li>
296<li>Changed the following issues from Review to Tentatively NAD: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#901">901</a>.</li>
297<li>Changed the following issues from Tentatively Ready to Tentatively NAD: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#822">822</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#988">988</a>.</li>
298<li>Changed the following issues from New to Tentatively NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#837">837</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#862">862</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#867">867</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#927">927</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#945">945</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#952">952</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#969">969</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#972">972</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#973">973</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#979">979</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1058">1058</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1060">1060</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1061">1061</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1077">1077</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1101">1101</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1109">1109</a>.</li>
299<li>Changed the following issues from Open to Tentatively NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#424">424</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#825">825</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#830">830</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#884">884</a>.</li>
300<li>Changed the following issues from Review to Tentatively NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1023">1023</a>.</li>
301<li>Changed the following issues from Open to Tentatively NAD Future: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#96">96</a>.</li>
302<li>Changed the following issues from New to Tentatively Ready: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#810">810</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#898">898</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#906">906</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#910">910</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#913">913</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#914">914</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#915">915</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#925">925</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#974">974</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#976">976</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#981">981</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#982">982</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#984">984</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#990">990</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#998">998</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#999">999</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1063">1063</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1067">1067</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1070">1070</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1073">1073</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1100">1100</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1103">1103</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1107">1107</a>.</li>
303<li>Changed the following issues from Open to Tentatively Ready: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#688">688</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#814">814</a>.</li>
304<li>Changed the following issues from Review to Tentatively Ready: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#899">899</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#907">907</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#909">909</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#934">934</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#938">938</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#940">940</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#943">943</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#950">950</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#965">965</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#970">970</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#975">975</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#986">986</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#991">991</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#993">993</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#994">994</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#997">997</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1002">1002</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1006">1006</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1011">1011</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1013">1013</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1014">1014</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1021">1021</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1024">1024</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1037">1037</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1038">1038</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1039">1039</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1040">1040</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1044">1044</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1045">1045</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1065">1065</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1066">1066</a>.</li>
305</ul></li>
306</ul>
307</li>
308<li>R64: 
3092009-05-01 mid-term mailing.
310<ul>
311<li><b>Summary:</b><ul>
312<li>346 open issues, up by 19.</li>
313<li>765 closed issues, up by 0.</li>
314<li>1111 issues total, up by 19.</li>
315</ul></li>
316<li><b>Details:</b><ul>
317<li>Added the following New issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1093">1093</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1094">1094</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1095">1095</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1096">1096</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1097">1097</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1098">1098</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1099">1099</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1100">1100</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1101">1101</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1102">1102</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1103">1103</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1104">1104</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1105">1105</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1106">1106</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1107">1107</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1108">1108</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1109">1109</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1110">1110</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1111">1111</a>.</li>
318<li>Changed the following issues from DR to CD1: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#130">130</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#386">386</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#406">406</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#409">409</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#413">413</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#434">434</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#438">438</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#444">444</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#445">445</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#455">455</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#457">457</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#460">460</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#469">469</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#533">533</a>.</li>
319<li>Changed the following issues from Review to New: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1070">1070</a>.</li>
320</ul></li>
321</ul>
322</li>
323<li>R63: 
3242009-03-20 post-Summit mailing.
325<ul>
326<li><b>Summary:</b><ul>
327<li>327 open issues, up by 96.</li>
328<li>765 closed issues, up by 14.</li>
329<li>1092 issues total, up by 110.</li>
330</ul></li>
331<li><b>Details:</b><ul>
332<li>Added the following NAD Editorial issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1022">1022</a>.</li>
333<li>Added the following NAD Future issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1025">1025</a>.</li>
334<li>Added the following New issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#983">983</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#984">984</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#985">985</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#989">989</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#990">990</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#995">995</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#996">996</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#998">998</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#999">999</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1001">1001</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1033">1033</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1054">1054</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1056">1056</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1057">1057</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1058">1058</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1059">1059</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1060">1060</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1061">1061</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1062">1062</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1063">1063</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1067">1067</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1068">1068</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1069">1069</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1071">1071</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1072">1072</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1073">1073</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1074">1074</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1076">1076</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1077">1077</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1080">1080</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1090">1090</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1091">1091</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1092">1092</a>.</li>
335<li>Added the following Open issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#987">987</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1000">1000</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1007">1007</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1008">1008</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1016">1016</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1017">1017</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1018">1018</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1020">1020</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1026">1026</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1027">1027</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1028">1028</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1029">1029</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1030">1030</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1031">1031</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1032">1032</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1034">1034</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1035">1035</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1036">1036</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1041">1041</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1042">1042</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1046">1046</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1048">1048</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1051">1051</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1052">1052</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1053">1053</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1055">1055</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1064">1064</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1075">1075</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1078">1078</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1079">1079</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1081">1081</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1082">1082</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1083">1083</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1084">1084</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1085">1085</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1086">1086</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1087">1087</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1088">1088</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1089">1089</a>.</li>
336<li>Added the following Review issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#986">986</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#991">991</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#992">992</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#993">993</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#994">994</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#997">997</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1002">1002</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1003">1003</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1004">1004</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1005">1005</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1006">1006</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1009">1009</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1010">1010</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1011">1011</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1012">1012</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1013">1013</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1014">1014</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1015">1015</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1019">1019</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1021">1021</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1023">1023</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1024">1024</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1037">1037</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1038">1038</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1039">1039</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1040">1040</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1043">1043</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1044">1044</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1045">1045</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1047">1047</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1049">1049</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1050">1050</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1065">1065</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1066">1066</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1070">1070</a>.</li>
337<li>Added the following Tentatively Ready issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#988">988</a>.</li>
338<li>Changed the following issues from New to Dup: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#905">905</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#942">942</a>.</li>
339<li>Changed the following issues from New to NAD: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#980">980</a>.</li>
340<li>Changed the following issues from New to NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#874">874</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#875">875</a>.</li>
341<li>Changed the following issues from Open to NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#732">732</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#793">793</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#794">794</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#800">800</a>.</li>
342<li>Changed the following issues from Pending NAD Editorial to NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#683">683</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#892">892</a>.</li>
343<li>Changed the following issues from Ready to NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#803">803</a>.</li>
344<li>Changed the following issues from NAD to Open: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#466">466</a>.</li>
345<li>Changed the following issues from NAD Future to Open: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#111">111</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#138">138</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#149">149</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#219">219</a>.</li>
346<li>Changed the following issues from New to Open: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#880">880</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#891">891</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#893">893</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#902">902</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#908">908</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#921">921</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#923">923</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#924">924</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#926">926</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#930">930</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#936">936</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#944">944</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#958">958</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#959">959</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#960">960</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#961">961</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#962">962</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#963">963</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#964">964</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#966">966</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#967">967</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#968">968</a>.</li>
347<li>Changed the following issues from Ready to Open: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#788">788</a>.</li>
348<li>Changed the following issues from New to Pending NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#937">937</a>.</li>
349<li>Changed the following issues from New to Review: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#879">879</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#899">899</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#901">901</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#907">907</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#909">909</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#929">929</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#934">934</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#938">938</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#940">940</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#943">943</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#950">950</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#965">965</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#970">970</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#971">971</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#975">975</a>.</li>
350<li>Changed the following issues from Open to Review: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#817">817</a>.</li>
351<li>Changed the following issues from New to Tentatively Ready: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#904">904</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#922">922</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#928">928</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#931">931</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#932">932</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#948">948</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#949">949</a>.</li>
352<li>Changed the following issues from Open to Tentatively Ready: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#890">890</a>.</li>
353<li>Changed the following issues from Review to Tentatively Ready: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#765">765</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#822">822</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#853">853</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#869">869</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#878">878</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#888">888</a>.</li>
354<li>Changed the following issues from Ready to WP: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#752">752</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#753">753</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#758">758</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#821">821</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#866">866</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#894">894</a>.</li>
355</ul></li>
356</ul>
357</li>
358<li>R62: 
3592009-02-06 pre-Summit mailing.
360<ul>
361<li><b>Summary:</b><ul>
362<li>231 open issues, up by 44.</li>
363<li>751 closed issues, up by 0.</li>
364<li>982 issues total, up by 44.</li>
365</ul></li>
366<li><b>Details:</b><ul>
367<li>Added the following New issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#939">939</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#940">940</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#941">941</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#942">942</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#943">943</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#944">944</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#945">945</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#946">946</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#947">947</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#948">948</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#949">949</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#950">950</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#951">951</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#952">952</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#953">953</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#954">954</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#955">955</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#956">956</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#957">957</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#958">958</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#959">959</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#960">960</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#961">961</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#962">962</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#963">963</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#964">964</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#965">965</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#966">966</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#967">967</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#968">968</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#969">969</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#970">970</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#971">971</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#972">972</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#973">973</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#974">974</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#975">975</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#976">976</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#977">977</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#978">978</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#979">979</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#980">980</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#981">981</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#982">982</a>.</li>
368</ul></li>
369</ul>
370</li>
371<li>R61: 
3722008-12-05 mid-term mailing.
373<ul>
374<li><b>Summary:</b><ul>
375<li>187 open issues, up by 20.</li>
376<li>751 closed issues, up by 0.</li>
377<li>938 issues total, up by 20.</li>
378</ul></li>
379<li><b>Details:</b><ul>
380<li>Added the following New issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#919">919</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#920">920</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#921">921</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#922">922</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#923">923</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#924">924</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#925">925</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#926">926</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#927">927</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#928">928</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#929">929</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#930">930</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#931">931</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#932">932</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#933">933</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#934">934</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#935">935</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#936">936</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#937">937</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#938">938</a>.</li>
381</ul></li>
382</ul>
383</li>
384<li>R60: 
3852008-10-03 post-San Francisco mailing.
386<ul>
387<li><b>Summary:</b><ul>
388<li>167 open issues, down by 25.</li>
389<li>751 closed issues, up by 65.</li>
390<li>918 issues total, up by 40.</li>
391</ul></li>
392<li><b>Details:</b><ul>
393<li>Added the following CD1 issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#882">882</a>.</li>
394<li>Added the following New issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#879">879</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#880">880</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#891">891</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#893">893</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#897">897</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#898">898</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#899">899</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#900">900</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#901">901</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#902">902</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#903">903</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#904">904</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#905">905</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#906">906</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#907">907</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#908">908</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#909">909</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#910">910</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#911">911</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#912">912</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#913">913</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#914">914</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#915">915</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#916">916</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#917">917</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#918">918</a>.</li>
395<li>Added the following Open issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#881">881</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#883">883</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#884">884</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#885">885</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#886">886</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#887">887</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#889">889</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#890">890</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#895">895</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#896">896</a>.</li>
396<li>Added the following Pending NAD Editorial issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#892">892</a>.</li>
397<li>Added the following Ready issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#894">894</a>.</li>
398<li>Added the following Review issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#888">888</a>.</li>
399<li>Changed the following issues from New to CD1: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#818">818</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#820">820</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#843">843</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#845">845</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#846">846</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#856">856</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#858">858</a>.</li>
400<li>Changed the following issues from Ready to CD1: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#180">180</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#387">387</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#396">396</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#522">522</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#629">629</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#691">691</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#713">713</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#714">714</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#720">720</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#728">728</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#762">762</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#769">769</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#771">771</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#772">772</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#776">776</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#779">779</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#787">787</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#805">805</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#806">806</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#807">807</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#808">808</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#809">809</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#813">813</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#824">824</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#829">829</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#842">842</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#844">844</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#848">848</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#850">850</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#852">852</a>.</li>
401<li>Changed the following issues from Review to CD1: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#23">23</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#675">675</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#692">692</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#698">698</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#709">709</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#734">734</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#804">804</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#823">823</a>.</li>
402<li>Changed the following issues from WP to CD1: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#44">44</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#49">49</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#76">76</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#91">91</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#92">92</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#98">98</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#103">103</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#109">109</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#117">117</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#118">118</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#120">120</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#123">123</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#136">136</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#153">153</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#165">165</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#167">167</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#171">171</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#179">179</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#182">182</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#183">183</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#184">184</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#185">185</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#186">186</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#187">187</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#198">198</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#200">200</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#201">201</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#202">202</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#206">206</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#214">214</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#221">221</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#225">225</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#226">226</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#228">228</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#229">229</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#230">230</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#231">231</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#232">232</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#233">233</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#234">234</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#235">235</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#237">237</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#238">238</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#239">239</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#240">240</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#241">241</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#242">242</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#243">243</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#247">247</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#248">248</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#250">250</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#251">251</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#252">252</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#253">253</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#254">254</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#256">256</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#258">258</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#259">259</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#260">260</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#261">261</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#262">262</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#263">263</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#264">264</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#265">265</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#266">266</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#268">268</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#270">270</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#271">271</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#272">272</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#273">273</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#274">274</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#275">275</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#276">276</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#278">278</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#280">280</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#281">281</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#282">282</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#283">283</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#284">284</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#285">285</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#286">286</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#288">288</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#291">291</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#292">292</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#294">294</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#295">295</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#297">297</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#298">298</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#300">300</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#301">301</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#303">303</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#305">305</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#306">306</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#307">307</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#308">308</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#310">310</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#311">311</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#312">312</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#315">315</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#316">316</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#317">317</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#318">318</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#319">319</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#320">320</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#321">321</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#322">322</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#324">324</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#325">325</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#327">327</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#328">328</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#329">329</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#331">331</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#333">333</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#334">334</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#335">335</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#336">336</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#337">337</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#338">338</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#339">339</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#340">340</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#341">341</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#345">345</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#346">346</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#347">347</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#349">349</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#352">352</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#354">354</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#355">355</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#358">358</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#359">359</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#360">360</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#362">362</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#363">363</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#364">364</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#365">365</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#369">369</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#370">370</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#371">371</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#373">373</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#375">375</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#376">376</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#379">379</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#380">380</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#381">381</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#383">383</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#384">384</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#389">389</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#391">391</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#395">395</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#400">400</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#401">401</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#402">402</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#403">403</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#404">404</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#405">405</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#407">407</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#410">410</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#411">411</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#412">412</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#414">414</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#415">415</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#416">416</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#420">420</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#422">422</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#425">425</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#426">426</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#428">428</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#432">432</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#435">435</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#436">436</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#441">441</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#442">442</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#443">443</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#448">448</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#449">449</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#453">453</a>, <a 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href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#530">530</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#531">531</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#534">534</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#535">535</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#537">537</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#538">538</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#540">540</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#541">541</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#542">542</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#543">543</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#545">545</a>, <a 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href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#623">623</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#624">624</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#628">628</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#634">634</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#638">638</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#640">640</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#643">643</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#646">646</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#650">650</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#651">651</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#652">652</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#654">654</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#655">655</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#660">660</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#661">661</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#664">664</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#665">665</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#666">666</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#672">672</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#673">673</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#674">674</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#677">677</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#678">678</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#679">679</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#680">680</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#681">681</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#682">682</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#685">685</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#687">687</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#689">689</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#693">693</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#694">694</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#695">695</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#699">699</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#700">700</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#703">703</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#705">705</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#706">706</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#710">710</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#712">712</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#715">715</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#722">722</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#740">740</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#743">743</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#744">744</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#746">746</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#749">749</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#755">755</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#759">759</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#761">761</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#766">766</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#768">768</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#770">770</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#775">775</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#777">777</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#778">778</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#781">781</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#782">782</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#783">783</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#789">789</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#792">792</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#798">798</a>.</li>
403<li>Changed the following issues from Open to Dup: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#670">670</a>.</li>
404<li>Changed the following issues from New to NAD: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#849">849</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#855">855</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#871">871</a>.</li>
405<li>Changed the following issues from Open to NAD: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#454">454</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#832">832</a>.</li>
406<li>Changed the following issues from New to NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#811">811</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#812">812</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#841">841</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#864">864</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#870">870</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#872">872</a>.</li>
407<li>Changed the following issues from Open to NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#299">299</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#484">484</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#556">556</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#631">631</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#676">676</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#704">704</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#724">724</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#742">742</a>.</li>
408<li>Changed the following issues from Pending NAD Editorial to NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#532">532</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#594">594</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#717">717</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#725">725</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#738">738</a>.</li>
409<li>Changed the following issues from New to Open: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#721">721</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#751">751</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#814">814</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#816">816</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#817">817</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#819">819</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#827">827</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#836">836</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#838">838</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#847">847</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#857">857</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#859">859</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#860">860</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#861">861</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#868">868</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#873">873</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#876">876</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#877">877</a>.</li>
410<li>Changed the following issues from Pending NAD Editorial to Open: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#424">424</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#625">625</a>.</li>
411<li>Changed the following issues from Review to Open: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#851">851</a>.</li>
412<li>Changed the following issues from New to Ready: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#788">788</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#821">821</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#866">866</a>.</li>
413<li>Changed the following issues from Open to Ready: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#753">753</a>.</li>
414<li>Changed the following issues from Review to Ready: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#752">752</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#758">758</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#803">803</a>.</li>
415<li>Changed the following issues from New to Review: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#765">765</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#822">822</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#853">853</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#854">854</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#869">869</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#878">878</a>.</li>
416<li>Changed the following issues from TC to TC1: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1">1</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#3">3</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#5">5</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#7">7</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#8">8</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#9">9</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#11">11</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#13">13</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#14">14</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#15">15</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#16">16</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#17">17</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#18">18</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#19">19</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#20">20</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#21">21</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#22">22</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#24">24</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#25">25</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#26">26</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#27">27</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#28">28</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#29">29</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#30">30</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#31">31</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#32">32</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#33">33</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#34">34</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#35">35</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#36">36</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#37">37</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#38">38</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#39">39</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#40">40</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#41">41</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#42">42</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#46">46</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#47">47</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#48">48</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#50">50</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#51">51</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#52">52</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#53">53</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#54">54</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#55">55</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#56">56</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#57">57</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#59">59</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#60">60</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#61">61</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#62">62</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#63">63</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#64">64</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#66">66</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#68">68</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#69">69</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#70">70</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#71">71</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#74">74</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#75">75</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#78">78</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#79">79</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#80">80</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#83">83</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#86">86</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#90">90</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#106">106</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#108">108</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#110">110</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#112">112</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#114">114</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#115">115</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#119">119</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#122">122</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#124">124</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#125">125</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#126">126</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#127">127</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#129">129</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#132">132</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#133">133</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#134">134</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#137">137</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#139">139</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#141">141</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#142">142</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#144">144</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#146">146</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#147">147</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#148">148</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#150">150</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#151">151</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#152">152</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#154">154</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#155">155</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#156">156</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#158">158</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#159">159</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#160">160</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#161">161</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#164">164</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#168">168</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#169">169</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#170">170</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#172">172</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#173">173</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#174">174</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#175">175</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#176">176</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#181">181</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#189">189</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#193">193</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#195">195</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#199">199</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#208">208</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#209">209</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#210">210</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#211">211</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#212">212</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#217">217</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#220">220</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#222">222</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#223">223</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#224">224</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#227">227</a>.</li>
417</ul></li>
418</ul>
419</li>
420<li>R59: 
4212008-08-22 pre-San Francisco mailing.
422<ul>
423<li><b>Summary:</b><ul>
424<li>192 open issues, up by 9.</li>
425<li>686 closed issues, up by 0.</li>
426<li>878 issues total, up by 9.</li>
427</ul></li>
428<li><b>Details:</b><ul>
429<li>Added the following New issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#870">870</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#871">871</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#872">872</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#873">873</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#874">874</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#875">875</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#876">876</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#877">877</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#878">878</a>.</li>
430</ul></li>
431</ul>
432</li>
433<li>R58: 
4342008-07-28 mid-term mailing.
435<ul>
436<li><b>Summary:</b><ul>
437<li>183 open issues, up by 12.</li>
438<li>686 closed issues, down by 4.</li>
439<li>869 issues total, up by 8.</li>
440</ul></li>
441<li><b>Details:</b><ul>
442<li>Added the following New issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#862">862</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#863">863</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#864">864</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#865">865</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#866">866</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#867">867</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#868">868</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#869">869</a>.</li>
443<li>Changed the following issues from Pending NAD Editorial to NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#393">393</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#557">557</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#592">592</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#754">754</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#757">757</a>.</li>
444<li>Changed the following issues from Pending WP to Open: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#644">644</a>.</li>
445<li>Changed the following issues from WP to Ready: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#387">387</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#629">629</a>.</li>
446<li>Changed the following issues from Pending NAD Editorial to Review: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#709">709</a>.</li>
447</ul></li>
448</ul>
449</li>
450<li>R57: 
4512008-06-27 post-Sophia Antipolis mailing.
452<ul>
453<li><b>Summary:</b><ul>
454<li>171 open issues, down by 20.</li>
455<li>690 closed issues, up by 43.</li>
456<li>861 issues total, up by 23.</li>
457</ul></li>
458<li><b>Details:</b><ul>
459<li>Added the following NAD issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#840">840</a>.</li>
460<li>Added the following New issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#841">841</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#843">843</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#845">845</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#846">846</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#847">847</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#849">849</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#853">853</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#854">854</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#855">855</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#856">856</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#857">857</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#858">858</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#859">859</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#860">860</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#861">861</a>.</li>
461<li>Added the following Open issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#839">839</a>.</li>
462<li>Added the following Ready issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#842">842</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#844">844</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#848">848</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#850">850</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#852">852</a>.</li>
463<li>Added the following Review issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#851">851</a>.</li>
464<li>Changed the following issues from New to NAD: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#826">826</a>.</li>
465<li>Changed the following issues from Open to NAD: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#570">570</a>.</li>
466<li>Changed the following issues from New to NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#786">786</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#831">831</a>.</li>
467<li>Changed the following issues from Open to NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#756">756</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#767">767</a>.</li>
468<li>Changed the following issues from New to Open: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#723">723</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#726">726</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#794">794</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#815">815</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#825">825</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#830">830</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#833">833</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#834">834</a>.</li>
469<li>Changed the following issues from Ready to Open: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#471">471</a>.</li>
470<li>Changed the following issues from Review to Open: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#539">539</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#711">711</a>.</li>
471<li>Changed the following issues from New to Ready: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#713">713</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#714">714</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#769">769</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#772">772</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#779">779</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#787">787</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#805">805</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#806">806</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#807">807</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#808">808</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#809">809</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#813">813</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#824">824</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#829">829</a>.</li>
472<li>Changed the following issues from Open to Ready: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#180">180</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#396">396</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#522">522</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#720">720</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#762">762</a>.</li>
473<li>Changed the following issues from Review to Ready: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#691">691</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#728">728</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#771">771</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#776">776</a>.</li>
474<li>Changed the following issues from New to Review: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#692">692</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#698">698</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#752">752</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#804">804</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#823">823</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#828">828</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#832">832</a>.</li>
475<li>Changed the following issues from Open to Review: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#23">23</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#675">675</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#734">734</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#803">803</a>.</li>
476<li>Changed the following issues from Ready to Review: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#758">758</a>.</li>
477<li>Changed the following issues from Ready to WP: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#387">387</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#518">518</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#550">550</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#574">574</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#595">595</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#596">596</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#612">612</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#618">618</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#629">629</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#638">638</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#672">672</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#673">673</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#685">685</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#710">710</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#715">715</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#722">722</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#740">740</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#743">743</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#744">744</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#746">746</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#749">749</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#755">755</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#759">759</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#761">761</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#766">766</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#768">768</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#770">770</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#775">775</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#777">777</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#778">778</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#781">781</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#782">782</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#783">783</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#789">789</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#792">792</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#798">798</a>.</li>
478</ul></li>
479</ul>
480</li>
481<li>R56: 
4822008-05-16 pre-Sophia Antipolis mailing.
483<ul>
484<li><b>Summary:</b><ul>
485<li>191 open issues, up by 24.</li>
486<li>647 closed issues, up by 1.</li>
487<li>838 issues total, up by 25.</li>
488</ul></li>
489<li><b>Details:</b><ul>
490<li>Added the following New issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#814">814</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#815">815</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#816">816</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#817">817</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#818">818</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#819">819</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#820">820</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#821">821</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#822">822</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#823">823</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#824">824</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#825">825</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#826">826</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#827">827</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#828">828</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#829">829</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#830">830</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#831">831</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#832">832</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#833">833</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#834">834</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#835">835</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#836">836</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#837">837</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#838">838</a>.</li>
491<li>Changed the following issues from New to NAD: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#802">802</a>.</li>
492</ul></li>
493</ul>
494</li>
495<li>R55: 
4962008-03-14 post-Bellevue mailing.
497<ul>
498<li><b>Summary:</b><ul>
499<li>167 open issues, down by 39.</li>
500<li>646 closed issues, up by 65.</li>
501<li>813 issues total, up by 26.</li>
502</ul></li>
503<li><b>Details:</b><ul>
504<li>Added the following Dup issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#795">795</a>.</li>
505<li>Added the following NAD issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#790">790</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#791">791</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#796">796</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#797">797</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#799">799</a>.</li>
506<li>Added the following New issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#788">788</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#794">794</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#802">802</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#804">804</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#805">805</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#806">806</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#807">807</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#808">808</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#809">809</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#810">810</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#811">811</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#812">812</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#813">813</a>.</li>
507<li>Added the following Open issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#793">793</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#800">800</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#801">801</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#803">803</a>.</li>
508<li>Added the following Ready issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#789">789</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#792">792</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#798">798</a>.</li>
509<li>Changed the following issues from NAD Future to Dup: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#116">116</a>.</li>
510<li>Changed the following issues from NAD Future to NAD: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#188">188</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#323">323</a>.</li>
511<li>Changed the following issues from New to NAD: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#729">729</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#730">730</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#731">731</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#733">733</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#735">735</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#736">736</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#737">737</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#739">739</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#741">741</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#745">745</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#748">748</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#763">763</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#764">764</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#773">773</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#784">784</a>.</li>
512<li>Changed the following issues from Open to NAD: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#388">388</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#462">462</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#579">579</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#627">627</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#653">653</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#686">686</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#707">707</a>.</li>
513<li>Changed the following issues from NAD Future to NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#140">140</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#390">390</a>.</li>
514<li>Changed the following issues from Open to NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#529">529</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#626">626</a>.</li>
515<li>Changed the following issues from Review to NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#645">645</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#684">684</a>.</li>
516<li>Changed the following issues from NAD Future to Open: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#128">128</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#180">180</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#190">190</a>.</li>
517<li>Changed the following issues from New to Open: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#617">617</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#718">718</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#719">719</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#720">720</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#724">724</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#732">732</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#734">734</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#742">742</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#747">747</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#750">750</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#753">753</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#756">756</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#760">760</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#762">762</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#767">767</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#774">774</a>.</li>
518<li>Changed the following issues from Ready to Open: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#675">675</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#676">676</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#688">688</a>.</li>
519<li>Changed the following issues from New to Pending NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#709">709</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#717">717</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#725">725</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#738">738</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#754">754</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#757">757</a>.</li>
520<li>Changed the following issues from Open to Pending NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#424">424</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#557">557</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#625">625</a>.</li>
521<li>Changed the following issues from New to Ready: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#710">710</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#715">715</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#722">722</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#740">740</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#743">743</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#744">744</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#746">746</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#749">749</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#755">755</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#758">758</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#759">759</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#761">761</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#766">766</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#768">768</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#770">770</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#775">775</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#777">777</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#778">778</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#781">781</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#782">782</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#783">783</a>.</li>
522<li>Changed the following issues from Open to Ready: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#387">387</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#471">471</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#550">550</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#612">612</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#629">629</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#673">673</a>.</li>
523<li>Changed the following issues from Review to Ready: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#518">518</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#574">574</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#596">596</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#618">618</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#638">638</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#672">672</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#685">685</a>.</li>
524<li>Changed the following issues from New to Review: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#711">711</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#728">728</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#771">771</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#776">776</a>.</li>
525<li>Changed the following issues from Open to Review: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#539">539</a>.</li>
526<li>Changed the following issues from Ready to WP: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#561">561</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#562">562</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#563">563</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#567">567</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#581">581</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#620">620</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#621">621</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#622">622</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#623">623</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#624">624</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#661">661</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#664">664</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#665">665</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#666">666</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#674">674</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#679">679</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#680">680</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#687">687</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#689">689</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#693">693</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#694">694</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#695">695</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#700">700</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#703">703</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#705">705</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#706">706</a>.</li>
527<li>Changed the following issues from Tentatively Ready to WP: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#527">527</a>.</li>
528</ul></li>
529</ul>
530</li>
531<li>R54: 
5322008-02-01 pre-Bellevue mailing.
533<ul>
534<li><b>Summary:</b><ul>
535<li>206 open issues, up by 23.</li>
536<li>581 closed issues, up by 0.</li>
537<li>787 issues total, up by 23.</li>
538</ul></li>
539<li><b>Details:</b><ul>
540<li>Added the following New issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#765">765</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#766">766</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#767">767</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#768">768</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#769">769</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#770">770</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#771">771</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#772">772</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#773">773</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#774">774</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#775">775</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#776">776</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#777">777</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#778">778</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#779">779</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#780">780</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#781">781</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#782">782</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#783">783</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#784">784</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#785">785</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#786">786</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#787">787</a>.</li>
541<li>Changed the following issues from NAD Future to Dup: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#105">105</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#348">348</a>.</li>
542<li>Changed the following issues from NAD Future to NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#353">353</a>.</li>
543<li>Changed the following issues from New to NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#697">697</a>.</li>
544<li>Changed the following issues from NAD Future to Open: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#388">388</a>.</li>
545<li>Changed the following issues from Open to Tentatively Ready: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#527">527</a>.</li>
546</ul></li>
547</ul>
548</li>
549<li>R53: 
5502007-12-09 mid-term mailing.
551<ul>
552<li><b>Summary:</b><ul>
553<li>183 open issues, up by 11.</li>
554<li>581 closed issues, down by 1.</li>
555<li>764 issues total, up by 10.</li>
556</ul></li>
557<li><b>Details:</b><ul>
558<li>Added the following New issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#755">755</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#756">756</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#757">757</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#758">758</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#759">759</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#760">760</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#761">761</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#762">762</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#763">763</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#764">764</a>.</li>
559<li>Changed the following issues from NAD to Open: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#463">463</a>.</li>
560<li>Changed the following issues from Pending WP to WP: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#607">607</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#608">608</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#654">654</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#655">655</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#677">677</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#682">682</a>.</li>
561</ul></li>
562</ul>
563</li>
564<li>R52: 
5652007-10-19 post-Kona mailing.
566<ul>
567<li><b>Summary:</b><ul>
568<li>172 open issues, up by 4.</li>
569<li>582 closed issues, up by 27.</li>
570<li>754 issues total, up by 31.</li>
571</ul></li>
572<li><b>Details:</b><ul>
573<li>Added the following New issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#724">724</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#725">725</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#726">726</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#727">727</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#728">728</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#729">729</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#730">730</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#731">731</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#732">732</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#733">733</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#734">734</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#735">735</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#736">736</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#737">737</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#738">738</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#739">739</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#740">740</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#741">741</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#742">742</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#743">743</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#744">744</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#745">745</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#746">746</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#747">747</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#748">748</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#749">749</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#750">750</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#751">751</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#752">752</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#753">753</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#754">754</a>.</li>
574<li>Changed the following issues from NAD Future to Dup: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#77">77</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#350">350</a>.</li>
575<li>Changed the following issues from New to NAD: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#639">639</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#657">657</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#663">663</a>.</li>
576<li>Changed the following issues from Open to NAD: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#548">548</a>.</li>
577<li>Changed the following issues from New to Open: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#546">546</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#550">550</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#564">564</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#565">565</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#573">573</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#585">585</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#588">588</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#627">627</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#629">629</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#630">630</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#632">632</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#635">635</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#653">653</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#659">659</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#667">667</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#668">668</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#669">669</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#670">670</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#671">671</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#673">673</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#686">686</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#704">704</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#707">707</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#708">708</a>.</li>
578<li>Changed the following issues from New to Pending NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#393">393</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#592">592</a>.</li>
579<li>Changed the following issues from New to Pending WP: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#607">607</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#608">608</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#654">654</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#655">655</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#677">677</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#682">682</a>.</li>
580<li>Changed the following issues from New to Ready: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#561">561</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#562">562</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#563">563</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#567">567</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#581">581</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#595">595</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#620">620</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#621">621</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#622">622</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#623">623</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#624">624</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#661">661</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#664">664</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#665">665</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#666">666</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#674">674</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#675">675</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#676">676</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#679">679</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#687">687</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#688">688</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#689">689</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#693">693</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#694">694</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#695">695</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#700">700</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#703">703</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#705">705</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#706">706</a>.</li>
581<li>Changed the following issues from Open to Ready: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#680">680</a>.</li>
582<li>Changed the following issues from New to Review: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#574">574</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#596">596</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#618">618</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#638">638</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#645">645</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#672">672</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#684">684</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#685">685</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#691">691</a>.</li>
583<li>Changed the following issues from New to WP: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#552">552</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#634">634</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#650">650</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#651">651</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#652">652</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#678">678</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#681">681</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#699">699</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#712">712</a>.</li>
584<li>Changed the following issues from Open to WP: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#258">258</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#401">401</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#524">524</a>.</li>
585<li>Changed the following issues from Ready to WP: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#488">488</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#577">577</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#660">660</a>.</li>
586</ul></li>
587</ul>
588</li>
589<li>R51: 
5902007-09-09 pre-Kona mailing.
591<ul>
592<li><b>Summary:</b><ul>
593<li>168 open issues, up by 15.</li>
594<li>555 closed issues, up by 0.</li>
595<li>723 issues total, up by 15.</li>
596</ul></li>
597<li><b>Details:</b><ul>
598<li>Added the following New issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#709">709</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#710">710</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#711">711</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#712">712</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#713">713</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#714">714</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#715">715</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#716">716</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#717">717</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#718">718</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#719">719</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#720">720</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#721">721</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#722">722</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#723">723</a>.</li>
599</ul></li>
600</ul>
601</li>
602<li>R50: 
6032007-08-05 post-Toronto mailing.
604<ul>
605<li><b>Summary:</b><ul>
606<li>153 open issues, down by 5.</li>
607<li>555 closed issues, up by 17.</li>
608<li>708 issues total, up by 12.</li>
609</ul></li>
610<li><b>Details:</b><ul>
611<li>Added the following New issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#697">697</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#698">698</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#699">699</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#700">700</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#701">701</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#702">702</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#703">703</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#704">704</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#705">705</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#706">706</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#707">707</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#708">708</a>.</li>
612<li>Changed the following issues from New to NAD: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#583">583</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#584">584</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#662">662</a>.</li>
613<li>Changed the following issues from Open to NAD: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#528">528</a>.</li>
614<li>Changed the following issues from New to NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#637">637</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#647">647</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#658">658</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#690">690</a>.</li>
615<li>Changed the following issues from Open to NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#525">525</a>.</li>
616<li>Changed the following issues from Pending NAD Editorial to NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#553">553</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#571">571</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#591">591</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#633">633</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#636">636</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#641">641</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#642">642</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#648">648</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#649">649</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#656">656</a>.</li>
617<li>Changed the following issues from New to Open: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#579">579</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#631">631</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#680">680</a>.</li>
618<li>Changed the following issues from Pending WP to Open: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#258">258</a>.</li>
619<li>Changed the following issues from Ready to Pending WP: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#644">644</a>.</li>
620<li>Changed the following issues from New to Ready: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#577">577</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#660">660</a>.</li>
621<li>Changed the following issues from Open to Ready: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#488">488</a>.</li>
622<li>Changed the following issues from Open to Review: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#518">518</a>.</li>
623<li>Changed the following issues from Ready to TRDec: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#604">604</a>.</li>
624<li>Changed the following issues from DR to WP: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#453">453</a>.</li>
625<li>Changed the following issues from Ready to WP: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#531">531</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#551">551</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#566">566</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#628">628</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#640">640</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#643">643</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#646">646</a>.</li>
626</ul></li>
627</ul>
628</li>
629<li>R49: 
6302007-06-23 pre-Toronto mailing.
631<ul>
632<li><b>Summary:</b><ul>
633<li>158 open issues, up by 13.</li>
634<li>538 closed issues, up by 7.</li>
635<li>696 issues total, up by 20.</li>
636</ul></li>
637<li><b>Details:</b><ul>
638<li>Added the following New issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#677">677</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#678">678</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#679">679</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#680">680</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#681">681</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#682">682</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#684">684</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#685">685</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#686">686</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#687">687</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#688">688</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#689">689</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#690">690</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#691">691</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#692">692</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#693">693</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#694">694</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#695">695</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#696">696</a>.</li>
639<li>Added the following Pending NAD Editorial issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#683">683</a>.</li>
640<li>Changed the following issues from New to NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#587">587</a>.</li>
641<li>Changed the following issues from Open to NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#590">590</a>.</li>
642<li>Changed the following issues from New to Pending NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#636">636</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#642">642</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#648">648</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#649">649</a>.</li>
643</ul></li>
644</ul>
645</li>
646<li>R48: 
6472007-05-06 post-Oxford mailing.
648<ul>
649<li><b>Summary:</b><ul>
650<li>145 open issues, down by 33.</li>
651<li>531 closed issues, up by 53.</li>
652<li>676 issues total, up by 20.</li>
653</ul></li>
654<li><b>Details:</b><ul>
655<li>Added the following New issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#657">657</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#658">658</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#659">659</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#660">660</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#661">661</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#662">662</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#663">663</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#664">664</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#665">665</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#666">666</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#667">667</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#668">668</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#669">669</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#670">670</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#671">671</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#672">672</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#673">673</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#674">674</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#675">675</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#676">676</a>.</li>
656<li>Changed the following issues from Tentatively Ready to Dup: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#479">479</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#536">536</a>.</li>
657<li>Changed the following issues from Tentatively Ready to NAD: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#385">385</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#463">463</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#466">466</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#470">470</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#515">515</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#526">526</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#547">547</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#560">560</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#572">572</a>.</li>
658<li>Changed the following issues from NAD to NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#351">351</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#357">357</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#368">368</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#499">499</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#504">504</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#512">512</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#513">513</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#514">514</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#516">516</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#544">544</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#549">549</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#555">555</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#558">558</a>.</li>
659<li>Changed the following issues from Tentatively Ready to NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#482">482</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#615">615</a>.</li>
660<li>Changed the following issues from NAD_Future to NAD Future: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#77">77</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#105">105</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#111">111</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#116">116</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#128">128</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#138">138</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#140">140</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#149">149</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#180">180</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#188">188</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#190">190</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#219">219</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#323">323</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#348">348</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#350">350</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#353">353</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#388">388</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#390">390</a>.</li>
661<li>Changed the following issues from Tentatively Ready to Open: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#471">471</a>.</li>
662<li>Changed the following issues from New to Pending NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#633">633</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#641">641</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#656">656</a>.</li>
663<li>Changed the following issues from Tentatively Ready to Pending NAD Editorial: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#532">532</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#553">553</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#571">571</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#591">591</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#594">594</a>.</li>
664<li>Changed the following issues from Tentatively Ready to Pending WP: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#258">258</a>.</li>
665<li>Changed the following issues from New to Ready: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#566">566</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#628">628</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#640">640</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#643">643</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#644">644</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#646">646</a>.</li>
666<li>Changed the following issues from Review to Ready: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#531">531</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#551">551</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#604">604</a>.</li>
667<li>Changed the following issues from Ready to TRDec: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#598">598</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#599">599</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#600">600</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#601">601</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#602">602</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#603">603</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#605">605</a>.</li>
668<li>Changed the following issues from Ready to WP: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#543">543</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#545">545</a>.</li>
669<li>Changed the following issues from Tentatively Ready to WP: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#201">201</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#206">206</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#233">233</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#254">254</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#416">416</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#422">422</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#456">456</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#534">534</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#542">542</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#559">559</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#575">575</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#576">576</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#578">578</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#586">586</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#589">589</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#593">593</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#609">609</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#610">610</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#611">611</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#613">613</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#616">616</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#619">619</a>.</li>
670</ul></li>
671</ul>
672</li>
673<li>R47: 
6742007-03-09 pre-Oxford mailing.
675<ul>
676<li><b>Summary:</b><ul>
677<li>178 open issues, up by 37.</li>
678<li>478 closed issues, up by 0.</li>
679<li>656 issues total, up by 37.</li>
680</ul></li>
681<li><b>Details:</b><ul>
682<li>Added the following New issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#620">620</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#621">621</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#622">622</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#623">623</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#624">624</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#627">627</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#628">628</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#629">629</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#630">630</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#631">631</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#632">632</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#633">633</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#634">634</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#635">635</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#636">636</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#637">637</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#638">638</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#639">639</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#640">640</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#641">641</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#642">642</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#643">643</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#644">644</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#645">645</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#646">646</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#647">647</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#648">648</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#649">649</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#650">650</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#651">651</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#652">652</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#653">653</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#654">654</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#655">655</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#656">656</a>.</li>
683<li>Added the following Open issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#625">625</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#626">626</a>.</li>
684<li>Changed the following issues from New to Open: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#570">570</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#580">580</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#582">582</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#590">590</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#612">612</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#614">614</a>.</li>
685<li>Changed the following issues from New to Tentatively Ready: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#547">547</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#553">553</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#560">560</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#571">571</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#572">572</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#575">575</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#576">576</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#578">578</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#586">586</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#589">589</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#591">591</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#593">593</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#594">594</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#609">609</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#610">610</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#611">611</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#613">613</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#615">615</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#616">616</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#619">619</a>.</li>
686<li>Changed the following issues from Open to Tentatively Ready: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#201">201</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#206">206</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#233">233</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#254">254</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#258">258</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#385">385</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#416">416</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#422">422</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#456">456</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#463">463</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#466">466</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#470">470</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#471">471</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#479">479</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#482">482</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#515">515</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#526">526</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#532">532</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#536">536</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#542">542</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#559">559</a>.</li>
687<li>Changed the following issues from Review to Tentatively Ready: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#534">534</a>.</li>
688</ul></li>
689</ul>
690</li>
691<li>R46: 
6922007-01-12 mid-term mailing.
693<ul>
694<li><b>Summary:</b><ul>
695<li>141 open issues, up by 11.</li>
696<li>478 closed issues, down by 1.</li>
697<li>619 issues total, up by 10.</li>
698</ul></li>
699<li><b>Details:</b><ul>
700<li>Added new issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#610">610</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#611">611</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#612">612</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#613">613</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#614">614</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#615">615</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#616">616</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#617">617</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#618">618</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#619">619</a>.</li>
701</ul></li>
702</ul>
703</li>
704<li>R45: 
7052006-11-03 post-Portland mailing.
706<ul>
707<li><b>Summary:</b><ul>
708<li>130 open issues, up by 0.</li>
709<li>479 closed issues, up by 17.</li>
710<li>609 issues total, up by 17.</li>
711</ul></li>
712<li><b>Details:</b><ul>
713<li>Moved issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#520">520</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#521">521</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#530">530</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#535">535</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#537">537</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#538">538</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#540">540</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#541">541</a> to WP.</li>
714<li>Moved issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#504">504</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#512">512</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#516">516</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#544">544</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#549">549</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#554">554</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#555">555</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#558">558</a> to NAD.</li>
715<li>Moved issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#569">569</a> to Dup.</li>
716<li>Moved issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#518">518</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#523">523</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#524">524</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#542">542</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#556">556</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#557">557</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#559">559</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#597">597</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#606">606</a> to Open.</li>
717<li>Moved issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#543">543</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#545">545</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#549">549</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#549">549</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#598">598</a> - <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#603">603</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#605">605</a> to Ready.</li>
718<li>Moved issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#531">531</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#551">551</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#604">604</a> to Review.</li>
719<li>Added new issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#593">593</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#594">594</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#595">595</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#596">596</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#597">597</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#598">598</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#599">599</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#600">600</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#601">601</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#602">602</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#603">603</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#604">604</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#605">605</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#606">606</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#607">607</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#608">608</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#609">609</a>.</li>
720</ul></li>
721</ul>
722</li>
723<li>R44: 
7242006-09-08 pre-Portland mailing.
725<ul>
726<li><b>Summary:</b><ul>
727<li>130 open issues, up by 6.</li>
728<li>462 closed issues, down by 1.</li>
729<li>592 issues total, up by 5.</li>
730</ul></li>
731<li><b>Details:</b><ul>
732<li>Added new issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#583">583</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#584">584</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#585">585</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#586">586</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#587">587</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#588">588</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#589">589</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#590">590</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#591">591</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#592">592</a>.</li>
733</ul></li>
734</ul>
735</li>
736<li>R43: 
7372006-06-23 mid-term mailing.
738<ul>
739<li><b>Summary:</b><ul>
740<li>124 open issues, up by 14.</li>
741<li>463 closed issues, down by 1.</li>
742<li>587 issues total, up by 13.</li>
743</ul></li>
744<li><b>Details:</b><ul>
745<li>Added new issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#575">575</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#576">576</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#577">577</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#578">578</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#579">579</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#580">580</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#581">581</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#582">582</a>.</li>
746<li>Reopened <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#255">255</a>.</li>
747<li>Moved issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#520">520</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#541">541</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#544">544</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#569">569</a> to Tentatively Ready.</li>
748</ul></li>
749</ul>
750</li>
751<li>R42: 
7522006-04-21 post-Berlin mailing.
753<ul>
754<li><b>Summary:</b><ul>
755<li>110 open issues, down by 16.</li>
756<li>464 closed issues, up by 24.</li>
757<li>574 issues total, up by 8.</li>
758</ul></li>
759<li><b>Details:</b><ul>
760<li>Added new issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#567">567</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#568">568</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#569">569</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#570">570</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#571">571</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#572">572</a>.</li>
761<li>Moved issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#499">499</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#501">501</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#506">506</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#509">509</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#510">510</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#511">511</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#513">513</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#514">514</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#517">517</a> to NAD.</li>
762<li>Moved issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#502">502</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#503">503</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#515">515</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#516">516</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#522">522</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#525">525</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#526">526</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#527">527</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#528">528</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#529">529</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#532">532</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#536">536</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#539">539</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#548">548</a> to Open.</li>
763<li>Moved issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#504">504</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#512">512</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#521">521</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#530">530</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#531">531</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#535">535</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#537">537</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#538">538</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#540">540</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#549">549</a> to Ready.</li>
764<li>Moved issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#247">247</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#294">294</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#362">362</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#369">369</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#371">371</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#376">376</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#384">384</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#475">475</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#478">478</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#495">495</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#497">497</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#505">505</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#507">507</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#508">508</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#519">519</a> to WP.</li>
765<li>Moved issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#534">534</a> to Review.</li>
766</ul></li>
767</ul>
768</li>
769<li>R41: 
7702006-02-24 pre-Berlin mailing.
771<ul>
772<li><b>Summary:</b><ul>
773<li>126 open issues, up by 31.</li>
774<li>440 closed issues, up by 0.</li>
775<li>566 issues total, up by 31.</li>
776</ul></li>
777<li><b>Details:</b><ul>
778<li>Added new issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#536">536</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#537">537</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#538">538</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#539">539</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#540">540</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#541">541</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#542">542</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#543">543</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#544">544</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#545">545</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#546">546</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#547">547</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#548">548</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#549">549</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#550">550</a> ,<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#551">551</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#552">552</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#553">553</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#554">554</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#555">555</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#556">556</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#557">557</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#558">558</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#559">559</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#560">560</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#561">561</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#562">562</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#563">563</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#564">564</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#565">565</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#566">566</a>.</li>
779<li>Moved <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#342">342</a> from Ready to Open.</li>
780<li>Reopened <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#309">309</a>.</li>
781</ul></li>
782</ul>
783</li>
784<li>R40: 
7852005-12-16 mid-term mailing.
786<ul>
787<li><b>Summary:</b><ul>
788<li>95 open issues.</li>
789<li>440 closed issues.</li>
790<li>535 issues total.</li>
791</ul></li>
792<li><b>Details:</b><ul>
793<li>Added new issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#529">529</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#530">530</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#531">531</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#532">532</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#533">533</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#534">534</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#535">535</a>.</li>
794</ul></li>
795</ul>
796</li>
797<li>R39: 
7982005-10-14 post-Mont Tremblant mailing.
799Added new issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#526">526</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#528">528</a>.
800Moved issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#280">280</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#461">461</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#464">464</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#465">465</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#467">467</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#468">468</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#474">474</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#496">496</a> from Ready to WP as per the vote from Mont Tremblant.
801Moved issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#247">247</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#294">294</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#342">342</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#362">362</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#369">369</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#371">371</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#376">376</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#384">384</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#475">475</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#478">478</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#495">495</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#497">497</a> from Review to Ready.
802Moved issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#498">498</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#504">504</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#506">506</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#509">509</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#510">510</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#511">511</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#512">512</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#513">513</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#514">514</a> from New to Open.
803Moved issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#505">505</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#507">507</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#508">508</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#519">519</a> from New to Ready.
804Moved issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#500">500</a> from New to NAD.
805Moved issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#518">518</a> from New to Review.
806</li>
807<li>R38: 
8082005-07-03 pre-Mont Tremblant mailing.
809Merged open TR1 issues in <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#504">504</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#522">522</a>.
810Added new issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#523">523</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#523">523</a>
811</li>
812<li>R37: 
8132005-06 mid-term mailing.
814Added new issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#498">498</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#503">503</a>.
815</li>
816<li>R36: 
8172005-04 post-Lillehammer mailing. All issues in "ready" status except
818for <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#454">454</a> were moved to "DR" status, and all issues
819previously in "DR" status were moved to "WP".
820</li>
821<li>R35: 
8222005-03 pre-Lillehammer mailing.
823</li>
824<li>R34: 
8252005-01 mid-term mailing.  Added new issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#488">488</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#494">494</a>.
826</li>
827<li>R33: 
8282004-11 post-Redmond mailing. Reflects actions taken in Redmond.
829</li>
830<li>R32: 
8312004-09 pre-Redmond mailing: reflects new proposed resolutions and
832new issues received after the 2004-07 mailing.  Added
833new issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#479">479</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#481">481</a>.
834</li>
835<li>R31: 
8362004-07 mid-term mailing: reflects new proposed resolutions and
837new issues received after the post-Sydney mailing.  Added
838new issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#463">463</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#478">478</a>.
839</li>
840<li>R30: 
841Post-Sydney mailing: reflects decisions made at the Sydney meeting.
842Voted all "Ready" issues from R29 into the working paper.
843Added new issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#460">460</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#462">462</a>.
844</li>
845<li>R29: 
846Pre-Sydney mailing.  Added new issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#441">441</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#457">457</a>.
847</li>
848<li>R28: 
849Post-Kona mailing: reflects decisions made at the Kona meeting.
850Added new issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#432">432</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#440">440</a>.
851</li>
852<li>R27: 
853Pre-Kona mailing.  Added new issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#404">404</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#431">431</a>.
854</li>
855<li>R26: 
856Post-Oxford mailing: reflects decisions made at the Oxford meeting.
857All issues in Ready status were voted into DR status.  All issues in
858DR status were voted into WP status.
859</li>
860<li>R25: 
861Pre-Oxford mailing.  Added new issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#390">390</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#402">402</a>.
862</li>
863<li>R24: 
864Post-Santa Cruz mailing: reflects decisions made at the Santa Cruz
865meeting.  All Ready issues from R23 with the exception of <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#253">253</a>, which has been given a new proposed resolution, were
866moved to DR status.  Added new issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#383">383</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#389">389</a>.  (Issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#387">387</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#389">389</a> were discussed
867at the meeting.)  Made progress on issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#225">225</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#226">226</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#229">229</a>: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#225">225</a> and <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#229">229</a> have been moved to Ready status, and the only remaining
868concerns with <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#226">226</a> involve wording.
869</li>
870<li>R23: 
871Pre-Santa Cruz mailing.  Added new issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#367">367</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#382">382</a>.
872Moved issues in the TC to TC status.
873</li>
874<li>R22: 
875Post-Cura�ao mailing.  Added new issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#362">362</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#366">366</a>.
876</li>
877<li>R21: 
878Pre-Cura�ao mailing.  Added new issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#351">351</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#361">361</a>.
879</li>
880<li>R20: 
881Post-Redmond mailing; reflects actions taken in Redmond.  Added
882new issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#336">336</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#350">350</a>, of which issues 
883<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#347">347</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#350">350</a> were added since Redmond, hence
884not discussed at the meeting.  
885
886All Ready issues were moved to DR status, with the exception of issues
887<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#284">284</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#241">241</a>, and <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#267">267</a>.
888
889Noteworthy issues discussed at Redmond include 
890<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#120">120</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#202">202</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#226">226</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#233">233</a>, 
891<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#270">270</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#253">253</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#254">254</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#323">323</a>.
892</li>
893<li>R19: 
894Pre-Redmond mailing.  Added new issues 
895<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#323">323</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#335">335</a>.
896</li>
897<li>R18: 
898Post-Copenhagen mailing; reflects actions taken in Copenhagen.
899Added new issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#312">312</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#317">317</a>, and discussed
900new issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#271">271</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#314">314</a>.
901
902Changed status of issues
903<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#103">103</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#118">118</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#136">136</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#153">153</a>
904<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#165">165</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#171">171</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#183">183</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#184">184</a>
905<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#185">185</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#186">186</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#214">214</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#221">221</a>
906<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#234">234</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#237">237</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#243">243</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#248">248</a>
907<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#251">251</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#252">252</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#256">256</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#260">260</a>
908<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#261">261</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#262">262</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#263">263</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#265">265</a>
909<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#268">268</a>
910to DR.
911
912Changed status of issues
913<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#49">49</a>  <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#109">109</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#117">117</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#182">182</a>
914<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#228">228</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#230">230</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#232">232</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#235">235</a>
915<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#238">238</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#241">241</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#242">242</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#250">250</a>
916<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#259">259</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#264">264</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#266">266</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#267">267</a>
917<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#271">271</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#272">272</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#273">273</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#275">275</a>
918<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#281">281</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#284">284</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#285">285</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#286">286</a>
919<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#288">288</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#292">292</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#295">295</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#297">297</a>
920<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#298">298</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#301">301</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#303">303</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#306">306</a>
921<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#307">307</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#308">308</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#312">312</a>
922to Ready.
923
924Closed issues 
925<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#111">111</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#277">277</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#279">279</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#287">287</a>
926<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#289">289</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#293">293</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#302">302</a> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#313">313</a>
927<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#314">314</a>
928as NAD.
929
930</li>
931<li>R17: 
932Pre-Copenhagen mailing.  Converted issues list to XML.  Added proposed
933resolutions for issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#49">49</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#76">76</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#91">91</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#235">235</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#250">250</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#267">267</a>.
934Added new issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#278">278</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#311">311</a>.
935</li>
936<li>R16:  
937post-Toronto mailing; reflects actions taken in Toronto. Added new
938issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#265">265</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#277">277</a>.  Changed status of issues
939<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#3">3</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#8">8</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#9">9</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#19">19</a>,
940<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#26">26</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#31">31</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#61">61</a>,
941<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#63">63</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#86">86</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#108">108</a>,
942<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#112">112</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#114">114</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#115">115</a>,
943<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#122">122</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#127">127</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#129">129</a>,
944<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#134">134</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#137">137</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#142">142</a>,
945<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#144">144</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#146">146</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#147">147</a>,
946<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#159">159</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#164">164</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#170">170</a>,
947<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#181">181</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#199">199</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#208">208</a>,
948<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#209">209</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#210">210</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#211">211</a>,
949<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#212">212</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#217">217</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#220">220</a>,
950<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#222">222</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#223">223</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#224">224</a>,
951<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#227">227</a> to "DR".  Reopened issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#23">23</a>. Reopened
952issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#187">187</a>. Changed issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#2">2</a> and
953<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#4">4</a> to NAD. Fixed a typo in issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#17">17</a>. Fixed
954issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#70">70</a>: signature should be changed both places it
955appears. Fixed issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#160">160</a>: previous version didn't fix
956the bug in enough places.
957</li>
958<li>R15: 
959pre-Toronto mailing. Added issues
960<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#233">233</a>-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#264">264</a>. Some small HTML formatting
961changes so that we pass Weblint tests.
962</li>
963<li>R14: 
964post-Tokyo II mailing; reflects committee actions taken in
965Tokyo. Added issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#228">228</a> to <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#232">232</a>. (00-0019R1/N1242)
966</li>
967<li>R13: 
968pre-Tokyo II updated: Added issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#212">212</a> to <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#227">227</a>.
969</li>
970<li>R12: 
971pre-Tokyo II mailing: Added issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#199">199</a> to
972<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#211">211</a>. Added "and paragraph 5" to the proposed resolution
973of issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#29">29</a>.  Add further rationale to issue
974<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#178">178</a>.
975</li>
976<li>R11: 
977post-Kona mailing: Updated to reflect LWG and full committee actions
978in Kona (99-0048/N1224). Note changed resolution of issues
979<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#4">4</a> and <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#38">38</a>. Added issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#196">196</a>
980to <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#198">198</a>. Closed issues list split into "defects" and
981"closed" documents.  Changed the proposed resolution of issue
982<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#4">4</a> to NAD, and changed the wording of proposed resolution
983of issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#38">38</a>.
984</li>
985<li>R10: 
986pre-Kona updated.  Added proposed resolutions <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#83">83</a>,
987<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#86">86</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#91">91</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#92">92</a>,
988<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#109">109</a>. Added issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#190">190</a> to
989<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#195">195</a>. (99-0033/D1209, 14 Oct 99)
990</li>
991<li>R9: 
992pre-Kona mailing.  Added issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#140">140</a> to
993<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#189">189</a>. Issues list split into separate "active" and
994"closed" documents. (99-0030/N1206, 25 Aug 99)
995</li>
996<li>R8: 
997post-Dublin mailing. Updated to reflect LWG and full committee actions
998in Dublin. (99-0016/N1193, 21 Apr 99)
999</li>
1000<li>R7: 
1001pre-Dublin updated: Added issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#130">130</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#131">131</a>,
1002<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#132">132</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#133">133</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#134">134</a>,
1003<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#135">135</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#136">136</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#137">137</a>,
1004<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#138">138</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#139">139</a> (31 Mar 99)
1005</li>
1006<li>R6: 
1007pre-Dublin mailing. Added issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#127">127</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#128">128</a>,
1008and <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#129">129</a>.  (99-0007/N1194, 22 Feb 99)
1009</li>
1010<li>R5: 
1011update issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#103">103</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#112">112</a>; added issues
1012<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#114">114</a> to <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#126">126</a>. Format revisions to prepare
1013for making list public. (30 Dec 98)
1014</li>
1015<li>R4: 
1016post-Santa Cruz II updated: Issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#110">110</a>,
1017<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#111">111</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#112">112</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#113">113</a> added, several
1018issues corrected. (22 Oct 98)
1019</li>
1020<li>R3: 
1021post-Santa Cruz II: Issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#94">94</a> to <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#109">109</a>
1022added, many issues updated to reflect LWG consensus (12 Oct 98)
1023</li>
1024<li>R2: 
1025pre-Santa Cruz II: Issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#73">73</a> to <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#93">93</a> added,
1026issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#17">17</a> updated. (29 Sep 98)
1027</li>
1028<li>R1: 
1029Correction to issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#55">55</a> resolution, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#60">60</a> code
1030format, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#64">64</a> title. (17 Sep 98)
1031</li>
1032</ul>
1033
1034<h2><a name="Status"></a>Issue Status</h2>
1035
1036  <p><b><a name="New">New</a></b> - The issue has not yet been
1037  reviewed by the LWG. Any <b>Proposed Resolution</b> is purely a
1038  suggestion from the issue submitter, and should not be construed as
1039  the view of LWG.</p>
1040
1041  <p><b><a name="Open">Open</a></b> - The LWG has discussed the issue
1042  but is not yet ready to move the issue forward. There are several
1043  possible reasons for open status:</p>
1044     <ul>
1045        <li>Consensus may have not yet have been reached as to how to deal
1046            with the issue.</li>
1047        <li>Informal consensus may have been reached, but the LWG awaits
1048            exact <b>Proposed Resolution</b> wording for review.</li>
1049        <li>The LWG wishes to consult additional technical experts before
1050            proceeding.</li>
1051        <li>The issue may require further study.</li>
1052     </ul>
1053
1054  <p>A <b>Proposed Resolution</b> for an open issue is still not be
1055  construed as the view of LWG. Comments on the current state of
1056  discussions are often given at the end of open issues in an italic
1057  font. Such comments are for information only and should not be given
1058  undue importance.</p>
1059
1060  <p><b><a name="Dup">Dup</a></b> - The LWG has reached consensus that
1061  the issue is a duplicate of another issue, and will not be further
1062  dealt with. A <b>Rationale</b> identifies the duplicated issue's
1063  issue number.  </p>
1064
1065  <p><b><a name="NAD">NAD</a></b> - The LWG has reached consensus that
1066  the issue is not a defect in the Standard.</p>
1067
1068  <p><b><a name="NAD Editorial">NAD Editorial</a></b> - The LWG has reached consensus that
1069  the issue can either be handled editorially, or is handled by a paper (usually
1070  linked to in the rationale).</p>
1071
1072  <p><b><a name="NAD Concepts">NAD Concepts</a></b> - The LWG has reached consensus that
1073  the issue is NAD for now, but represents a real issue when the library is
1074  done with language-supported concepts.</p>
1075
1076  <p><b><a name="NAD Future">NAD Future</a></b> - In addition to the regular
1077  status, the LWG believes that this issue should be revisited at the
1078  next revision of the standard.</p>
1079
1080  <p><b><a name="Review">Review</a></b> - Exact wording of a
1081  <b>Proposed Resolution</b> is now available for review on an issue
1082  for which the LWG previously reached informal consensus.</p>
1083
1084  <p><b><a name="Ready">Ready</a></b> - The LWG has reached consensus
1085  that the issue is a defect in the Standard, the <b>Proposed
1086  Resolution</b> is correct, and the issue is ready to forward to the
1087  full committee for further action as a Defect Report (DR).</p>
1088
1089  <p><b><a name="DR">DR</a></b> - (Defect Report) - The full J16
1090  committee has voted to forward the issue to the Project Editor to be
1091  processed as a Potential Defect Report. The Project Editor reviews
1092  the issue, and then forwards it to the WG21 Convenor, who returns it
1093  to the full committee for final disposition. This issues list
1094  accords the status of DR to all these Defect Reports regardless of
1095  where they are in that process.</p>
1096
1097  <p><b><a name="TC1">TC1</a></b> - (Technical Corrigenda 1) - The full
1098  WG21 committee has voted to accept the Defect Report's Proposed
1099  Resolution as a Technical Corrigenda.  Action on this issue is thus
1100  complete and no further action is possible under ISO rules.</p>
1101
1102  <p><b><a name="CD1">CD1</a></b> - (Committee Draft 2008) - The full
1103  WG21 committee has voted to accept the Defect Report's Proposed
1104  Resolution into the Fall 2008 Committee Draft.</p>
1105
1106  <p><b><a name="TRDec">TRDec</a></b> - (Decimal TR defect) - The 
1107  LWG has voted to accept the Defect Report's Proposed
1108  Resolution into the Decimal TR.  Action on this issue is thus
1109  complete and no further action is expected.</p>
1110
1111  <p><b><a name="WP">WP</a></b> - (Working Paper) - The proposed
1112  resolution has not been accepted as a Technical Corrigendum, but
1113  the full WG21 committee has voted to apply the Defect Report's Proposed
1114  Resolution to the working paper.</p>
1115
1116  <p><b>Tentatively</b> - This is a <i>status qualifier</i>.  The issue has
1117  been reviewed online, or at an unofficial meeting, but not in an official meeting, and some support has been formed
1118  for the qualified status.  Tentatively qualified issues may be moved to the unqualified status
1119  and forwarded to full committee (if Ready) within the same meeting.  Unlike Ready issues, Tentatively Ready issues
1120  will be reviewed in subcommittee prior to forwarding to full committee.  When a status is
1121  qualified with Tentatively, the issue is still considered active.</p>
1122
1123  <p><b>Pending</b> - This is a <i>status qualifier</i>.  When prepended to
1124  a status this indicates the issue has been
1125  processed by the committee, and a decision has been made to move the issue to
1126  the associated unqualified status.  However for logistical reasons the indicated
1127  outcome of the issue has not yet appeared in the latest working paper.
1128
1129  </p><p>Issues are always given the status of <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a> when
1130  they first appear on the issues list. They may progress to
1131  <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a> or <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Review">Review</a> while the LWG
1132  is actively working on them. When the LWG has reached consensus on
1133  the disposition of an issue, the status will then change to
1134  <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Dup">Dup</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#NAD">NAD</a>, or
1135  <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a> as appropriate.  Once the full J16 committee votes to
1136  forward Ready issues to the Project Editor, they are given the
1137  status of Defect Report ( <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#DR">DR</a>). These in turn may
1138  become the basis for Technical Corrigenda (<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#TC">TC</a>),
1139  or are closed without action other than a Record of Response
1140  (<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#RR">RR</a> ). The intent of this LWG process is that
1141  only issues which are truly defects in the Standard move to the
1142  formal ISO DR status.
1143  </p>
1144
1145
1146<h2>Active Issues</h2>
1147<hr>
1148<h3><a name="296"></a>296. Missing descriptions and requirements of pair operators</h3>
1149<p><b>Section:</b> 20.3.4 [pairs] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
1150 <b>Submitter:</b> Martin Sebor <b>Opened:</b> 2001-01-14  <b>Last modified:</b> 2009-10-26</p>
1151<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#pairs">active issues</a> in [pairs].</p>
1152<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#pairs">issues</a> in [pairs].</p>
1153<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
1154<p><b>Discussion:</b></p>
1155<p>The synopsis of the header <tt>&lt;utility&gt;</tt> in 20.3 [utility]
1156lists the complete set of equality and relational operators for <tt>pair</tt>
1157but the section describing the template and the operators only describes
1158<tt>operator==()</tt> and <tt>operator&lt;()</tt>, and it fails to mention
1159any requirements on the template arguments. The remaining operators are
1160not mentioned at all.
1161</p>
1162
1163<p><i>[
11642009-09-27 Alisdair reopens.
1165]</i></p>
1166
1167
1168<blockquote>
1169<p>
1170The issue is a lack of wording specifying the semantics of <tt>std::pair</tt>
1171relational operators.  The rationale is that this is covered by
1172catch-all wording in the relops component, and that as relops directly
1173precedes <tt>pair</tt> in the document this is an easy connection to make.
1174</p>
1175
1176<p>
1177Reading the current working paper I make two observations:
1178</p>
1179
1180<ol type="i">
1181<li>
1182relops no longer immediately precedes <tt>pair</tt> in the order of
1183specification.  However, even if it did, there is a lot of <tt>pair</tt>
1184specification itself between the (apparently) unrelated relops and the
1185relational operators for <tt>pair</tt>.  (The catch-all still requires
1186<tt>operator==</tt> and <tt>operator&lt;</tt> to be specified
1187explicitly)
1188</li>
1189
1190<li>
1191No other library component relies on the catch-all clause. The following
1192all explicitly document all six relational operators, usually in a
1193manner that could have deferred to the relops clause.
1194</li>
1195</ol>
1196
1197<blockquote><pre>tuple
1198unique_ptr
1199duration
1200time_point
1201basic_string
1202queue
1203stack
1204move_iterator
1205reverse_iterator 
1206regex submatch
1207thread::id
1208</pre></blockquote>
1209
1210<p>
1211The container components provide their own (equivalent) definition in
121223.2.1 [container.requirements.general] Table 90 -- Container
1213requirements and do so do not defer to relops.
1214</p>
1215
1216<p>
1217<tt>Shared_ptr</tt> explicitly documents <tt>operator!=</tt> and does
1218not supply the other 3 missing operators
1219(<tt>&gt;</tt>,<tt>&gt;=</tt>,<tt>&lt;=</tt>) so does not meet the
1220reqirements of the relops clause.
1221</p>
1222
1223<p>
1224<tt>Weak_ptr</tt> only supports <tt>operator&lt;</tt> so would not be
1225covered by relops.
1226</p>
1227
1228<p>
1229At the very least I would request a note pointing to the relops clause
1230we rely on to provide this definition.  If this route is taken, I would
1231recommend reducing many of the above listed clauses to a similar note
1232rather than providing redundant specification.
1233</p>
1234
1235<p>
1236My preference would be to supply the 4 missing specifications consistent
1237with the rest of the library.
1238</p>
1239
1240</blockquote>
1241
1242<p><i>[
12432009-10-11 Daniel opens <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1233">1233</a> which deals with the same issue as
1244it pertains to <tt>unique_ptr</tt>.
1245]</i></p>
1246
1247
1248<p><i>[
12492009-10 Santa Cruz:
1250]</i></p>
1251
1252
1253<blockquote>
1254Move to Ready
1255</blockquote>
1256
1257
1258
1259<p><b>Proposed resolution:</b></p>
1260<p>
1261After p20 20.3.4 [pairs] add:
1262</p>
1263
1264<blockquote><pre>template &lt;class T1, class T2&gt;
1265bool operator!=(const pair&lt;T1,T2&gt;&amp; x, const pair&lt;T1,T2&gt;&amp; y);
1266</pre>
1267
1268<blockquote>
1269<i>Returns:</i> <tt>!(x==y)</tt>
1270</blockquote>
1271
1272<pre>template &lt;class T1, class T2&gt;
1273bool operator&gt; (const pair&lt;T1,T2&gt;&amp; x, const pair&lt;T1,T2&gt;&amp; y);
1274</pre>
1275
1276<blockquote>
1277<i>Returns:</i> <tt>y &lt; x</tt>
1278</blockquote>
1279
1280<pre>template &lt;class T1, class T2&gt;
1281bool operator&gt;=(const pair&lt;T1,T2&gt;&amp; x, const pair&lt;T1,T2&gt;&amp; y);
1282</pre>
1283
1284<blockquote>
1285<i>Returns:</i> <tt>!(x &lt; y)</tt>
1286</blockquote>
1287
1288<pre>template &lt;class T1, class T2&gt;
1289bool operator&lt;=(const pair&lt;T1,T2&gt;&amp; x, const pair&lt;T1,T2&gt;&amp; y);
1290</pre>
1291
1292<blockquote>
1293<i>Returns:</i> <tt>!(y &lt; x)</tt>
1294</blockquote>
1295</blockquote>
1296
1297
1298<p><b>Rationale:</b></p>
1299<p>20.3.1 [operators] paragraph 10 already specifies the semantics.
1300That paragraph says that, if declarations of operator!=, operator&gt;,
1301operator&lt;=, and operator&gt;= appear without definitions, they are
1302defined as specified in 20.3.1 [operators].  There should be no user
1303confusion, since that paragraph happens to immediately precede the
1304specification of <tt>pair</tt>.</p>
1305
1306
1307
1308
1309
1310<hr>
1311<h3><a name="299"></a>299. Incorrect return types for iterator dereference</h3>
1312<p><b>Section:</b> 24.2.4 [bidirectional.iterators], 24.2.5 [random.access.iterators] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
1313 <b>Submitter:</b> John Potter <b>Opened:</b> 2001-01-22  <b>Last modified:</b> 2009-10-26</p>
1314<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#bidirectional.iterators">issues</a> in [bidirectional.iterators].</p>
1315<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
1316<p><b>Discussion:</b></p>
1317<p>
1318In section 24.2.4 [bidirectional.iterators],
1319Table 75 gives the return type of *r-- as convertible to T.  This is
1320not consistent with Table 74 which gives the return type of *r++ as
1321T&amp;.  *r++ = t is valid while *r-- = t is invalid.
1322</p>
1323
1324<p>
1325In section 24.2.5 [random.access.iterators],
1326Table 76 gives the return type of a[n] as convertible to T.  This is
1327not consistent with the semantics of *(a + n) which returns T&amp; by
1328Table 74.  *(a + n) = t is valid while a[n] = t is invalid.
1329</p>
1330
1331<p>
1332Discussion from the Copenhagen meeting: the first part is
1333uncontroversial.  The second part, operator[] for Random Access
1334Iterators, requires more thought.  There are reasonable arguments on
1335both sides.  Return by value from operator[] enables some potentially
1336useful iterators, e.g. a random access "iota iterator" (a.k.a
1337"counting iterator" or "int iterator").  There isn't any obvious way
1338to do this with return-by-reference, since the reference would be to a
1339temporary.  On the other hand, <tt>reverse_iterator</tt> takes an
1340arbitrary Random Access Iterator as template argument, and its
1341operator[] returns by reference.  If we decided that the return type
1342in Table 76 was correct, we would have to change
1343<tt>reverse_iterator</tt>.  This change would probably affect user
1344code.
1345</p>
1346
1347<p>
1348History: the contradiction between <tt>reverse_iterator</tt> and the
1349Random Access Iterator requirements has been present from an early
1350stage.  In both the STL proposal adopted by the committee
1351(N0527==94-0140) and the STL technical report (HPL-95-11 (R.1), by
1352Stepanov and Lee), the Random Access Iterator requirements say that
1353operator[]'s return value is "convertible to T".  In N0527
1354reverse_iterator's operator[] returns by value, but in HPL-95-11
1355(R.1), and in the STL implementation that HP released to the public,
1356reverse_iterator's operator[] returns by reference.  In 1995, the
1357standard was amended to reflect the contents of HPL-95-11 (R.1).  The
1358original intent for operator[] is unclear.
1359</p>
1360
1361<p>
1362In the long term it may be desirable to add more fine-grained 
1363iterator requirements, so that access method and traversal strategy
1364can be decoupled.  (See "Improved Iterator Categories and
1365Requirements", N1297 = 01-0011, by Jeremy Siek.)  Any decisions
1366about issue 299 should keep this possibility in mind.
1367</p>
1368
1369<p>Further discussion: I propose a compromise between John Potter's
1370resolution, which requires <tt>T&amp;</tt> as the return type of
1371<tt>a[n]</tt>, and the current wording, which requires convertible to
1372<tt>T</tt>. The compromise is to keep the convertible to <tt>T</tt>
1373for the return type of the expression <tt>a[n]</tt>, but to also add
1374<tt>a[n] = t</tt> as a valid expression. This compromise "saves" the
1375common case uses of random access iterators, while at the same time
1376allowing iterators such as counting iterator and caching file
1377iterators to remain random access iterators (iterators where the
1378lifetime of the object returned by <tt>operator*()</tt> is tied to the
1379lifetime of the iterator).
1380</p>
1381
1382<p>
1383Note that the compromise resolution necessitates a change to
1384<tt>reverse_iterator</tt>. It would need to use a proxy to support
1385<tt>a[n] = t</tt>.
1386</p>
1387
1388<p>
1389Note also there is one kind of mutable random access iterator that
1390will no longer meet the new requirements. Currently, iterators that
1391return an r-value from <tt>operator[]</tt> meet the requirements for a
1392mutable random access iterartor, even though the expression <tt>a[n] =
1393t</tt> will only modify a temporary that goes away. With this proposed
1394resolution, <tt>a[n] = t</tt> will be required to have the same
1395operational semantics as <tt>*(a + n) = t</tt>.
1396</p>
1397
1398<p><i>[
13992009-07-28 Reopened by Alisdair.  No longer solved by concepts.
1400]</i></p>
1401
1402
1403<p><i>[
14042009-09-18 Alisdair adds:
1405]</i></p>
1406
1407
1408<blockquote>
1409<p>
1410Why can't we write through the reference returned from operator[] on a
1411random access iterator?
1412</p>
1413
1414<p>
1415Recommended solution:
1416</p>
1417
1418<p>
1419In table Table 104 -- Random access iterator requirements, replace
1420</p>
1421
1422<blockquote>
1423a[n] : convertible to <del><tt>const T &amp;</tt></del>
1424<ins><tt>T&amp;</tt> if <tt>X</tt> is mutable, otherwise convertible to <tt>const T&amp;</tt></ins>
1425</blockquote>
1426</blockquote>
1427
1428<p><i>[
14292009-10 Santa Cruz:
1430]</i></p>
1431
1432
1433<blockquote>
1434Leave Open. Alisdair to spearhead a paper on revivification.
1435</blockquote>
1436
1437
1438
1439<p><b>Proposed resolution:</b></p>
1440
1441<p>
1442In section 24.1.4 [lib.bidirectdional.iterators], change the return
1443type in table 75 from "convertible to <tt>T</tt>" to
1444<tt>T&amp;</tt>.
1445</p>
1446
1447<p>
1448In section 24.1.5 [lib.random.access.iterators], change the
1449operational semantics for <tt>a[n]</tt> to " the r-value of
1450<tt>a[n]</tt> is equivalent to the r-value of <tt>*(a +
1451n)</tt>". Add a new row in the table for the expression <tt>a[n] = t</tt>
1452with a return type of convertible to <tt>T</tt> and operational semantics of
1453<tt>*(a + n) = t</tt>.
1454</p>
1455
1456<p><i>[Lillehammer: Real problem, but should be addressed as part of
1457  iterator redesign]</i></p>
1458
1459
1460
1461
1462<p><b>Rationale:</b></p>
1463<p><i>[
1464San Francisco:
1465]</i></p>
1466
1467
1468<blockquote>
1469Solved by
1470<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2758.pdf">N2758</a>.
1471</blockquote>
1472
1473
1474
1475
1476
1477
1478
1479<hr>
1480<h3><a name="397"></a>397. ostream::sentry dtor throws exceptions</h3>
1481<p><b>Section:</b> 27.7.2.4 [ostream::sentry] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
1482 <b>Submitter:</b> Martin Sebor <b>Opened:</b> 2003-01-05  <b>Last modified:</b> 2009-10-20</p>
1483<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#ostream::sentry">issues</a> in [ostream::sentry].</p>
1484<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
1485<p><b>Discussion:</b></p>
1486    <p>
148717.4.4.8, p3 prohibits library dtors from throwing exceptions.
1488    </p>
1489    <p>
149027.6.2.3, p4 says this about the ostream::sentry dtor:
1491    </p>
1492    <pre>    -4- If ((os.flags() &amp; ios_base::unitbuf) &amp;&amp; !uncaught_exception())
1493        is true, calls os.flush().
1494    </pre>
1495    <p>
149627.6.2.6, p7 that describes ostream::flush() says:
1497    </p>
1498    <pre>    -7- If rdbuf() is not a null pointer, calls rdbuf()-&gt;pubsync().
1499        If that function returns ?-1 calls setstate(badbit) (which
1500        may throw ios_base::failure (27.4.4.3)).
1501    </pre>
1502    <p>
1503That seems like a defect, since both pubsync() and setstate() can
1504throw an exception. 
1505    </p>
1506<p><i>[
1507The contradiction is real.  Clause 17 says destructors may never
1508throw exceptions, and clause 27 specifies a destructor that does
1509throw.  In principle we might change either one.  We're leaning
1510toward changing clause 17: putting in an "unless otherwise specified"
1511clause, and then putting in a footnote saying the sentry destructor
1512is the only one that can throw.  PJP suggests specifying that
1513sentry::~sentry() should internally catch any exceptions it might cause.
1514]</i></p>
1515
1516
1517<p><i>[
1518See <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#418">418</a> and <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#622">622</a> for related issues.
1519]</i></p>
1520
1521
1522<p><i>[
15232009-07 Frankfurt
1524]</i></p>
1525
1526
1527<blockquote>
1528<p>
1529Move to Review. Add "Throws: nothing" to the specification of ostream::sentry::~sentry().
1530</p>
1531</blockquote>
1532
1533<p><i>[
15342009-10-13 Daniel adds:
1535]</i></p>
1536
1537
1538<blockquote>
1539The proposed resolution of <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#835">835</a> is written to match the outcome
1540of this issue.
1541</blockquote>
1542
1543<p><i>[
15442009 Santa Cruz:
1545]</i></p>
1546
1547
1548<blockquote>
1549Move to Open.  Our intent is to solve this issue with <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#835">835</a>.
1550</blockquote>
1551
1552
1553
1554<p><b>Proposed resolution:</b></p>
1555<p>
1556Add after 27.7.2.4 [ostream::sentry] p17:
1557</p>
1558
1559<blockquote>
1560<pre>~sentry();
1561</pre>
1562<blockquote>
1563<p>
1564-17- If <tt>((os.flags() &amp; ios_base::unitbuf) &amp;&amp; !uncaught_exception())</tt>
1565is <tt>true</tt>, calls <tt>os.flush()</tt>.
1566</p>
1567
1568<p><ins>
1569<i>Throws:</i> Nothing.
1570</ins></p>
1571</blockquote>
1572</blockquote>
1573
1574
1575
1576
1577
1578<hr>
1579<h3><a name="408"></a>408. Is vector&lt;reverse_iterator&lt;char*&gt; &gt; forbidden?</h3>
1580<p><b>Section:</b> 24.2 [iterator.requirements] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
1581 <b>Submitter:</b> Nathan Myers <b>Opened:</b> 2003-06-03  <b>Last modified:</b> 2009-11-03</p>
1582<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#iterator.requirements">active issues</a> in [iterator.requirements].</p>
1583<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#iterator.requirements">issues</a> in [iterator.requirements].</p>
1584<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
1585<p><b>Discussion:</b></p>
1586<p>
1587I've been discussing iterator semantics with Dave Abrahams, and a 
1588surprise has popped up.  I don't think this has been discussed before.
1589</p>
1590
1591<p>
1592X [iterator.concepts] says that the only operation that can be performed on "singular"
1593iterator values is to assign a non-singular value to them.  (It 
1594doesn't say they can be destroyed, and that's probably a defect.)  
1595Some implementations have taken this to imply that there is no need 
1596to initialize the data member of a reverse_iterator&lt;&gt; in the default
1597constructor.  As a result, code like
1598</p>
1599<blockquote><pre>  std::vector&lt;std::reverse_iterator&lt;char*&gt; &gt; v(7);
1600  v.reserve(1000);
1601</pre></blockquote>
1602<p>
1603invokes undefined behavior, because it must default-initialize the
1604vector elements, and then copy them to other storage.  Of course many 
1605other vector operations on these adapters are also left undefined,
1606and which those are is not reliably deducible from the standard.
1607</p>
1608
1609<p>
1610I don't think that 24.1 was meant to make standard-library iterator 
1611types unsafe.  Rather, it was meant to restrict what operations may 
1612be performed by functions which take general user- and standard 
1613iterators as arguments, so that raw pointers would qualify as
1614iterators.  However, this is not clear in the text, others have come 
1615to the opposite conclusion.
1616</p>
1617
1618<p>
1619One question is whether the standard iterator adaptors have defined
1620copy semantics.  Another is whether they have defined destructor
1621semantics: is
1622</p>
1623<blockquote><pre>  { std::vector&lt;std::reverse_iterator&lt;char*&gt; &gt;  v(7); }
1624</pre></blockquote>
1625<p>
1626undefined too?
1627</p>
1628
1629<p>
1630Note this is not a question of whether algorithms are allowed to
1631rely on copy semantics for arbitrary iterators, just whether the
1632types we actually supply support those operations.  I believe the 
1633resolution must be expressed in terms of the semantics of the 
1634adapter's argument type.  It should make clear that, e.g., the 
1635reverse_iterator&lt;T&gt; constructor is actually required to execute
1636T(), and so copying is defined if the result of T() is copyable.
1637</p>
1638
1639<p>
1640Issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#235">235</a>, which defines reverse_iterator's default
1641constructor more precisely, has some relevance to this issue.
1642However, it is not the whole story.
1643</p>
1644
1645<p>
1646The issue was whether 
1647</p>
1648<blockquote><pre>  reverse_iterator() { }
1649</pre></blockquote>
1650<p>
1651is allowed, vs. 
1652</p>
1653<blockquote><pre>  reverse_iterator() : current() { }
1654</pre></blockquote>
1655
1656<p>
1657The difference is when T is char*, where the first leaves the member
1658uninitialized, and possibly equal to an existing pointer value, or
1659(on some targets) may result in a hardware trap when copied.
1660</p>
1661
1662<p>
16638.5 paragraph 5 seems to make clear that the second is required to
1664satisfy DR <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#235">235</a>, at least for non-class Iterator argument
1665types.
1666</p>
1667
1668<p>
1669But that only takes care of reverse_iterator, and doesn't establish
1670a policy for all iterators.  (The reverse iterator adapter was just
1671an example.)  In particular, does my function
1672</p>
1673<blockquote><pre>  template &lt;typename Iterator&gt;
1674    void f() { std::vector&lt;Iterator&gt;  v(7); } 
1675</pre></blockquote>
1676<p>
1677evoke undefined behavior for some conforming iterator definitions?
1678I think it does, now, because vector&lt;&gt; will destroy those singular
1679iterator values, and that's explicitly disallowed.
1680</p>
1681
1682<p>
168324.1 shouldn't give blanket permission to copy all singular iterators,
1684because then pointers wouldn't qualify as iterators.  However, it
1685should allow copying of that subset of singular iterator values that
1686are default-initialized, and it should explicitly allow destroying any
1687iterator value, singular or not, default-initialized or not.
1688</p>
1689
1690<p>Related issues: <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#407">407</a>, <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1012">1012</a></p>
1691<p><i>[
1692We don't want to require all singular iterators to be copyable,
1693because that is not the case for pointers.  However, default
1694construction may be a special case.  Issue: is it really default
1695construction we want to talk about, or is it something like value
1696initialization?  We need to check with core to see whether default
1697constructed pointers are required to be copyable; if not, it would be
1698wrong to impose so strict a requirement for iterators.
1699]</i></p>
1700
1701
1702<p><i>[
17032009-05-10 Alisdair provided wording.
1704]</i></p>
1705
1706
1707<blockquote>
1708The comments regarding destroying singular iterators have already been
1709resolved.  That just leaves copying (with moving implied).
1710</blockquote>
1711
1712<p><i>[
17132009-07 Frankfurt
1714]</i></p>
1715
1716
1717<blockquote>
1718<p>
1719This is related to LWG <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1012">1012</a>.
1720</p>
1721<p>
1722Note that there is a bug in the proposed resolution to LWG <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1012">1012</a>. The
1723change to  [reverse.iter.con] should be modified so that the word
1724"default" in the second sentence of the Effects clause is replaced by
1725"value."
1726</p>
1727<p>
1728We believe that the proposed fix to LWG <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1012">1012</a> (now corrected) is
1729sufficient to solve the problem for reverse_iterator. However, Alisdair
1730pointed out that LWG <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1012">1012</a> does not solve the general problem for authors
1731of iterator adaptors.
1732</p>
1733<p>
1734There are some problems with the proposed resolution. The phrase "safely
1735copyable" is not a term of art. Also, it mentions a
1736DefaultConstructible? concept.
1737</p>
1738<p>
1739Move to Review after Alisdair updates the wording.
1740</p>
1741</blockquote>
1742
1743<p><i>[
17442009-07-31 Alisdair revised wording:
1745]</i></p>
1746
1747
1748<p><i>[
17492009-08-17 Alisdair and Daniel collaborate on slightly revised wording.
1750This issue depends upon <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#724">724</a>
1751]</i></p>
1752
1753
1754<p><i>[
17552009-10-14 Daniel adds:
1756]</i></p>
1757
1758
1759<blockquote>
1760There is a clear dependency on <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1213">1213</a>, because the term "singular",
1761which is used as part of the resolution, is not properly defined yet.
1762</blockquote>
1763
1764<p><i>[
17652009-10 Santa Cruz:
1766]</i></p>
1767
1768
1769<blockquote>
1770Moved to Open. Alisdair will provide improved wording to make
1771this have "value semantics" and otherwise behave like a valid iterator.
1772</blockquote>
1773
1774
1775
1776<p><b>Proposed resolution:</b></p>
1777<p>
1778Add a new paragrpah to Iterator concepts 24.2 [iterator.requirements] after para 5 (the one describing
1779singular iterators)
1780</p>
1781<blockquote>
1782<p>
1783Just as a regular pointer to an array guarantees that there is a pointer
1784value pointing past the last element of the array, so for any iterator
1785type there is an iterator value that points past the last element of a
1786corresponding container. These values are called <i>past-the-end</i> values.
1787Values of an iterator <tt>i</tt> for which the expression <tt>*i</tt> is defined are called
1788<i>dereferenceable</i>. The library never assumes that past-the-end values are
1789dereferenceable. Iterators can also have singular values that are not
1790associated with any container. [<i>Example:</i> After the declaration of an
1791uninitialized pointer <tt>x</tt> (as with <tt>int* x;</tt>), <tt>x</tt> must always be assumed to
1792have a singular value of a pointer. &#8212; <i>end example</i>] Results of most
1793expressions are undefined for singular values; the only exceptions are
1794destroying an iterator that holds a singular value and the assignment of
1795a non-singular value to an iterator that holds a singular value. In this
1796case the singular value is overwritten the same way as any other value.
1797Dereferenceable values are always non-singular.
1798</p>
1799<p><ins>
1800After value-initialization, any iterator that satisfies the
1801<tt>DefaultConstructible</tt> requirements ([defaultconstructible]) shall not introduce undefined behaviour
1802when used <ins>as</ins> the
1803source of a copy or move operation, even if it would
1804otherwise be singular. [<i>Note:</i> This guarantee is not offered for
1805default-initialization (8.5 [dcl.init]), although the distinction only
1806matters for types with trivial default constructors such as pointers. &#8212;
1807<i>end note</i>]
1808</ins></p>
1809
1810
1811</blockquote>
1812
1813
1814
1815
1816
1817
1818<hr>
1819<h3><a name="427"></a>427. stage 2 and rationale of DR 221</h3>
1820<p><b>Section:</b> 22.4.2.1.2 [facet.num.get.virtuals] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
1821 <b>Submitter:</b> Martin Sebor <b>Opened:</b> 2003-09-18  <b>Last modified:</b> 2009-10-26</p>
1822<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#facet.num.get.virtuals">active issues</a> in [facet.num.get.virtuals].</p>
1823<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#facet.num.get.virtuals">issues</a> in [facet.num.get.virtuals].</p>
1824<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
1825<p><b>Discussion:</b></p>
1826<p>
1827The requirements specified in Stage 2 and reiterated in the rationale
1828of DR 221 (and echoed again in DR 303) specify that num_get&lt;charT&gt;::
1829do_get() compares characters on the stream against the widened elements
1830of "012...abc...ABCX+-"
1831</p>
1832
1833<p>
1834An implementation is required to allow programs to instantiate the num_get
1835template on any charT that satisfies the requirements on a user-defined
1836character type. These requirements do not include the ability of the
1837character type to be equality comparable (the char_traits template must
1838be used to perform tests for equality). Hence, the num_get template cannot
1839be implemented to support any arbitrary character type. The num_get template
1840must either make the assumption that the character type is equality-comparable
1841(as some popular implementations do), or it may use char_traits&lt;charT&gt; to do
1842the comparisons (some other popular implementations do that). This diversity
1843of approaches makes it difficult to write portable programs that attempt to
1844instantiate the num_get template on user-defined types.
1845</p>
1846
1847<p><i>[Kona: the heart of the problem is that we're theoretically
1848  supposed to use traits classes for all fundamental character
1849  operations like assignment and comparison, but facets don't have
1850  traits parameters.  This is a fundamental design flaw and it
1851  appears all over the place, not just in this one place.  It's not
1852  clear what the correct solution is, but a thorough review of facets
1853  and traits is in order.  The LWG considered and rejected the
1854  possibility of changing numeric facets to use narrowing instead of
1855  widening.  This may be a good idea for other reasons (see issue
1856  <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#459">459</a>), but it doesn't solve the problem raised by this
1857  issue.  Whether we use widen or narrow the <tt>num_get</tt> facet
1858  still has no idea which traits class the user wants to use for 
1859  the comparison, because only streams, not facets, are passed traits
1860  classes.   The standard does not require that two different
1861  traits classes with the same <tt>char_type</tt> must necessarily 
1862  have the same behavior.]</i></p>
1863
1864
1865<p>Informally, one possibility: require that some of the basic
1866character operations, such as <tt>eq</tt>, <tt>lt</tt>,
1867and <tt>assign</tt>, must behave the same way for all traits classes
1868with the same <tt>char_type</tt>.  If we accept that limitation on
1869traits classes, then the facet could reasonably be required to
1870use <tt>char_traits&lt;charT&gt;</tt>.</p>
1871
1872<p><i>[
18732009-07 Frankfurt
1874]</i></p>
1875
1876
1877<blockquote>
1878<p>
1879There was general agreement that the standard only needs to specify the
1880behavior when the character type is char or wchar_t.
1881</p>
1882<p>
1883Beman: we don't need to worry about C++1x because there is a non-zero
1884possibility that we would have a replacement facility for iostreams that
1885would solve these problems.
1886</p>
1887<p>
1888We need to change the following sentence in [locale.category], paragraph
18896 to specify that C is char and wchar_t:
1890</p>
1891<p>
1892"A template formal parameter with name C represents the set of all
1893possible specializations on a parameter that satisfies the requirements
1894for a character on which any member of the iostream components can be
1895instantiated."
1896</p>
1897<p>
1898We also need to specify in 27 that the basic character operations, such
1899as eq, lt, and assign use std::char_traits.
1900</p>
1901<p>
1902Daniel volunteered to provide wording.
1903</p>
1904</blockquote>
1905
1906<p><i>[
19072009-09-19 Daniel provided wording.
1908]</i></p>
1909
1910
1911<p><i>[
19122009-10 Santa Cruz:
1913]</i></p>
1914
1915
1916<blockquote>
1917Leave as Open. Alisdair and/or Tom will provide wording based on discussions.
1918We want to clearly state that streams and locales work just on <tt>char</tt>
1919and <tt>wchar_t</tt> (except where otherwise specified).
1920</blockquote>
1921
1922
1923
1924<p><b>Proposed resolution:</b></p>
1925<ol>
1926<li>
1927<p>
1928Change 22.3.1.1.1 [locale.category]/6:
1929</p>
1930
1931<blockquote>
1932[..] A template formal parameter with name <tt>C</tt> represents the set of all possible
1933specializations on a <ins><tt>char</tt> or <tt>wchar_t</tt></ins> parameter<del> that satisfies
1934the requirements for a character on which any of the iostream components
1935can be instantiated</del>. [..]
1936</blockquote>
1937</li>
1938
1939<li>
1940<p>
1941Add the following sentence to the end of 22.4.2 [category.numeric]/2:
1942</p>
1943
1944<blockquote>
1945[..] These specializations refer to [..], and also for the <tt>ctype&lt;&gt;</tt> facet to
1946perform character classification. <ins>Implementations are encouraged
1947but not required to use the <tt>char_traits&lt;charT&gt;</tt> functions for all
1948comparisons and assignments of characters of type <tt>charT</tt> that do
1949not belong to the set of required specializations.</ins>
1950</blockquote>
1951</li>
1952
1953<li>
1954<p>
1955Change 22.4.2.1.2 [facet.num.get.virtuals]/3:
1956</p>
1957
1958<blockquote>
1959<p>
1960Stage 2: If <tt>in==end</tt> then stage 2 terminates. Otherwise a <tt>charT</tt> is taken
1961from <tt>in</tt> and local variables are initialized as if by
1962</p>
1963
1964<blockquote><pre>char_type ct = *in;
1965<ins>using tr = char_traits&lt;char_type&gt;;
1966const char_type* pos = tr::find(atoms, sizeof(src) - 1, ct);</ins>
1967char c = src[<del>find(atoms, atoms + sizeof(src) - 1, ct) - atoms</del>
1968             <ins>pos ? pos - atoms : sizeof(src) - 1</ins>];
1969if (<ins>tr::eq(ct, </ins><del>ct == </del>use_facet&lt;numpunct&lt;charT&gt;(loc).decimal_point()<ins>)</ins>)
1970    c = '.';
1971bool discard =
1972    <ins>tr::eq(ct, </ins><del>ct == </del>use_facet&lt;numpunct&lt;charT&gt;(loc).thousands_sep()<ins>)</ins>
1973    &amp;&amp; use_facet&lt;numpunct&lt;charT&gt; &gt;(loc).grouping().length() != 0;
1974</pre></blockquote>
1975
1976<p>
1977where the values <tt>src</tt> and <tt>atoms</tt> are defined as if by: [..]
1978</p>
1979</blockquote>
1980
1981<p>
1982[Remark of the author: I considered to replace the initialization
1983"<tt>char_type ct = *in;</tt>"
1984by the sequence "<tt>char_type ct; tr::assign(ct, *in);</tt>", but decided
1985against it, because
1986it is a copy-initialization context, not an assignment]
1987</p>
1988</li>
1989
1990<li>
1991<p>
1992Add the following sentence to the end of 22.4.5 [category.time]/1:
1993</p>
1994
1995<blockquote>
1996[..] Their members use [..] , to determine formatting details.
1997<ins>Implementations are encouraged but not required to use the
1998<tt>char_traits&lt;charT&gt;</tt> functions for all comparisons and assignments
1999of characters of type <tt>charT</tt> that do
2000not belong to the set of required specializations.</ins>
2001</blockquote>
2002</li>
2003
2004<li>
2005<p>
2006Change 22.4.5.1.1 [locale.time.get.members]/8 bullet 4:
2007</p>
2008
2009<ul>
2010<li>
2011<del>The next element of <tt>fmt</tt> is equal to <tt>'%'</tt></del> <ins>For the next element <tt>c</tt>
2012of <tt>fmt char_traits&lt;char_type&gt;::eq(c, use_facet&lt;ctype&lt;char_type&gt;&gt;(f.getloc()).widen('%')) == true</tt></ins>,
2013[..]
2014</li>
2015</ul>
2016</li>
2017
2018<li>
2019<p>
2020Add the following sentence to the end of 22.4.6 [category.monetary]/2:
2021</p>
2022
2023<blockquote>
2024Their members use [..] to determine formatting details.
2025<ins>Implementations are encouraged but not required to use the
2026<tt>char_traits&lt;charT&gt;</tt> functions for all comparisons and assignments
2027of characters of type <tt>charT</tt> that do
2028not belong to the set of required specializations.</ins>
2029</blockquote>
2030</li>
2031
2032<li>
2033<p>
2034Change 22.4.6.1.2 [locale.money.get.virtuals]/4:
2035</p>
2036
2037<blockquote>
2038<p>
2039[..] The value <tt>units</tt> is produced as if by:
2040</p>
2041
2042<blockquote><pre>for (int i = 0; i &lt; n; ++i)
2043  buf2[i] = src[<ins>char_traits&lt;charT&gt;::</ins>find(atoms, <del>atoms+</del>sizeof(src), buf1[i]) - atoms];
2044buf2[n] = 0;
2045sscanf(buf2, "%Lf", &amp;units);
2046</pre></blockquote>
2047</blockquote>
2048</li>
2049
2050<li>
2051<p>
2052Change 22.4.6.2.2 [locale.money.put.virtuals]/1:
2053</p>
2054
2055<blockquote>
2056[..] for character buffers <tt>buf1</tt> and <tt>buf2</tt>. If <ins>for</ins> the first
2057character <ins><tt>c</tt></ins>
2058in <tt>digits</tt> or <tt>buf2</tt> <del>is equal to
2059<tt>ct.widen('-')</tt></del><ins><tt>char_traits&lt;charT&gt;::eq(c,
2060ct.widen('-')) == true</tt></ins>, [..]
2061</blockquote>
2062</li>
2063
2064<li>
2065<p>
2066Add a footnote to the first sentence of 27.7.1.2.2 [istream.formatted.arithmetic]/1:
2067</p>
2068
2069<blockquote>
2070<p>
2071As in the case of the inserters, these extractors depend on the locale's
2072<tt>num_get&lt;&gt;</tt> (22.4.2.1) object to perform parsing the input stream
2073data.<ins><sup>(footnote)</sup></ins> [..]
2074</p>
2075
2076<p>
2077<ins>
2078<sup>footnote)</sup> If the traits of the input stream has different semantics for <tt>lt()</tt>,
2079<tt>eq()</tt>, and <tt>assign()</tt> than <tt>char_traits&lt;char_type&gt;</tt>, this may give surprising
2080results.
2081</ins>
2082</p>
2083</blockquote>
2084</li>
2085
2086<li>
2087<p>
2088Add a footnote to the second sentence of 27.7.2.6.2 [ostream.inserters.arithmetic]/1:
2089</p>
2090
2091<blockquote>
2092<p>
2093<i>Effects:</i> The classes <tt>num_get&lt;&gt;</tt> and
2094<tt>num_put&lt;&gt;</tt> handle locale-dependent numeric formatting and
2095parsing. These inserter functions use the imbued locale value to perform
2096numeric formatting.<ins><sup>(footnote)</sup></ins> [..]
2097</p>
2098
2099<p>
2100<ins>
2101<sup>footnote)</sup> If the traits of the output stream has different semantics for <tt>lt()</tt>,
2102<tt>eq()</tt>, and <tt>assign()</tt> than <tt>char_traits&lt;char_type&gt;</tt>, this may give surprising
2103results.
2104</ins>
2105</p>
2106</blockquote>
2107</li>
2108
2109<li>
2110<p>
2111Add a footnote after the first sentence of 27.7.4 [ext.manip]/4:
2112</p>
2113
2114<blockquote>
2115<p>
2116<i>Returns:</i> An object of unspecified type such that if in is an object of type
2117<tt>basic_istream&lt;charT, traits&gt;</tt> then the expression <tt>in &gt;&gt; get_money(mon, intl)</tt>
2118behaves as if it called <tt>f(in, mon, intl)</tt>, where the function <tt>f</tt> is defined
2119as:<ins><sup>(footnote)</sup></ins> [..]
2120</p>
2121
2122<p>
2123<ins>
2124<sup>footnote)</sup> If the traits of the input stream has different semantics for <tt>lt()</tt>,
2125<tt>eq()</tt>, and <tt>assign()</tt> than <tt>char_traits&lt;char_type&gt;</tt>, this may give surprising
2126results.
2127</ins>
2128</p>
2129</blockquote>
2130</li>
2131
2132<li>
2133<p>
2134Add a footnote after the first sentence of 27.7.4 [ext.manip]/5:
2135</p>
2136
2137<blockquote>
2138<p>
2139<i>Returns:</i> An object of unspecified type such that if <tt>out</tt> is an object of type
2140<tt>basic_ostream&lt;charT, traits&gt;</tt> then the expression <tt>out &lt;&lt; put_money(mon, intl)</tt>
2141behaves as a formatted input function that calls <tt>f(out, mon, intl)</tt>, where the
2142function <tt>f</tt> is defined as:<ins><sup>(footnote)</sup></ins> [..]
2143</p>
2144
2145<p>
2146<ins>
2147<sup>footnote)</sup> If the traits of the output stream has different semantics for <tt>lt()</tt>,
2148<tt>eq()</tt>, and <tt>assign()</tt> than <tt>char_traits&lt;char_type&gt;</tt>, this may give surprising
2149results.
2150</ins>
2151</p>
2152</blockquote>
2153</li>
2154
2155<li>
2156<p>
215713) Add a footnote after the first sentence of 27.7.4 [ext.manip]/8:
2158</p>
2159
2160<blockquote>
2161<p>
2162<i>Returns:</i> An object of unspecified type such that if <tt>in</tt> is an
2163object of type b<tt>asic_istream&lt;charT, traits&gt;</tt> then the expression
2164<tt>in &gt;&gt;get_time(tmb, fmt)</tt> behaves as if it called <tt>f(in, tmb, fmt)</tt>,
2165where the function <tt>f</tt> is defined as:<ins><sup>(footnote)</sup></ins> [..]
2166</p>
2167
2168<p>
2169<ins>
2170<sup>footnote)</sup> If the traits of the input stream has different semantics for <tt>lt()</tt>,
2171<tt>eq()</tt>, and <tt>assign()</tt> than <tt>char_traits&lt;char_type&gt;</tt>, this may give surprising
2172results.
2173</ins>
2174</p>
2175</blockquote>
2176</li>
2177
2178<li>
2179<p>
2180Add a footnote after the first sentence of 27.7.4 [ext.manip]/10:
2181</p>
2182
2183<blockquote>
2184<p>
2185Returns: An object of unspecified type such that if <tt>out</tt> is an object of type
2186<tt>basic_ostream&lt;charT, traits&gt;</tt> then the expression <tt>out &lt;&lt;put_time(tmb, fmt)</tt>
2187behaves as if it called <tt>f(out, tmb, fmt)</tt>, where the function <tt>f</tt> is defined
2188as:<ins><sup>(footnote)</sup></ins> [..]
2189</p>
2190
2191<p>
2192<ins>
2193<sup>footnote)</sup> If the traits of the output stream has different semantics for <tt>lt()</tt>,
2194<tt>eq()</tt>, and <tt>assign()</tt> than <tt>char_traits&lt;char_type&gt;</tt>, this may give surprising
2195results.
2196</ins>
2197</p>
2198</blockquote>
2199</li>
2200</ol>
2201
2202
2203
2204
2205
2206<hr>
2207<h3><a name="430"></a>430. valarray subset operations</h3>
2208<p><b>Section:</b> 26.6.2.4 [valarray.sub] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
2209 <b>Submitter:</b> Martin Sebor <b>Opened:</b> 2003-09-18  <b>Last modified:</b> 2009-11-04</p>
2210<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
2211<p><b>Discussion:</b></p>
2212<p>
2213The standard fails to specify the behavior of valarray::operator[](slice)
2214and other valarray subset operations when they are passed an "invalid"
2215slice object, i.e., either a slice that doesn't make sense at all (e.g.,
2216slice (0, 1, 0) or one that doesn't specify a valid subset of the valarray
2217object (e.g., slice (2, 1, 1) for a valarray of size 1).
2218</p>
2219<p><i>[Kona: the LWG believes that invalid slices should invoke
2220  undefined behavior.  Valarrays are supposed to be designed for high
2221  performance, so we don't want to require specific checking.  We
2222  need wording to express this decision.]</i></p>
2223
2224
2225<p><i>[
2226Bellevue:
2227]</i></p>
2228
2229
2230<blockquote>
2231Please note that the standard also fails to specify the behavior of
2232slice_array and gslice_array in the valid case. Bill Plauger will
2233endeavor to provide revised wording for slice_array and gslice_array.
2234</blockquote>
2235
2236<p><i>[
2237post-Bellevue:  Bill provided wording.
2238]</i></p>
2239
2240
2241<p><i>[
22422009-07 Frankfurt
2243]</i></p>
2244
2245
2246<blockquote>
2247<p>
2248Move to Ready.
2249</p>
2250</blockquote>
2251
2252<p><i>[
22532009-11-04 Pete opens:
2254]</i></p>
2255
2256
2257<blockquote>
2258The resolution to LWG issue 430 has not been applied --- there have been
2259changes to the underlying text, and the resolution needs to be reworked.
2260</blockquote>
2261
2262
2263
2264<p><b>Proposed resolution:</b></p>
2265<p>
2266Insert after 26.6.2.4 [valarray.sub], paragraph 1:
2267</p>
2268
2269<blockquote>
2270<p>
2271The member operator is overloaded to provide several ways to select
2272sequences
2273of elements from among those controlled by <tt>*this</tt>. The first group of five
2274member operators work in conjunction with various overloads of <tt>operator=</tt>
2275(and other assigning operators) to allow selective replacement (slicing) of
2276the controlled sequence. The selected elements must exist.
2277</p>
2278<p>
2279The first member operator selects element off. For example:
2280</p>
2281
2282<blockquote><pre>valarray&lt;char&gt; v0("abcdefghijklmnop", 16);
2283v0[3] = 'A';
2284// v0 == valarray&lt;char&gt;("abcAefghijklmnop", 16)
2285</pre></blockquote>
2286
2287<p>
2288The second member operator selects those elements of the controlled sequence
2289designated by <tt>slicearr</tt>. For example:
2290</p>
2291
2292<blockquote><pre>valarray&lt;char&gt; v0("abcdefghijklmnop", 16);
2293valarray&lt;char&gt; v1("ABCDE", 5);
2294v0[slice(2, 5, 3)] = v1;
2295// v0 == valarray&lt;char&gt;("abAdeBghCjkDmnEp", 16)
2296</pre></blockquote>
2297
2298<p>
2299The third member operator selects those elements of the controlled sequence
2300designated by <tt>gslicearr</tt>. For example:
2301</p>
2302
2303<blockquote><pre>valarray&lt;char&gt; v0("abcdefghijklmnop", 16);
2304valarray&lt;char&gt; v1("ABCDEF", 6);
2305const size_t lv[] = {2, 3};
2306const size_t dv[] = {7, 2};
2307const valarray&lt;size_t&gt; len(lv, 2), str(dv, 2);
2308v0[gslice(3, len, str)] = v1;
2309// v0 == valarray&lt;char&gt;("abcAeBgCijDlEnFp", 16)
2310</pre></blockquote>
2311
2312<p>
2313The fourth member operator selects those elements of the controlled sequence
2314designated by <tt>boolarr</tt>. For example:
2315</p>
2316
2317<blockquote><pre>valarray&lt;char&gt; v0("abcdefghijklmnop", 16);
2318valarray&lt;char&gt; v1("ABC", 3);
2319const bool vb[] = {false, false, true, true, false, true};
2320v0[valarray&lt;bool&gt;(vb, 6)] = v1;
2321// v0 == valarray&lt;char&gt;("abABeCghijklmnop", 16)
2322</pre></blockquote>
2323
2324<p>
2325The fifth member operator selects those elements of the controlled sequence
2326designated by indarr. For example:
2327</p>
2328
2329<blockquote><pre>valarray&lt;char&gt; v0("abcdefghijklmnop", 16);
2330valarray&lt;char&gt; v1("ABCDE", 5);
2331const size_t vi[] = {7, 5, 2, 3, 8};
2332v0[valarray&lt;size_t&gt;(vi, 5)] = v1;
2333// v0 == valarray&lt;char&gt;("abCDeBgAEjklmnop", 16)
2334</pre></blockquote>
2335
2336<p>
2337The second group of five member operators each construct an object that
2338represents the value(s) selected. The selected elements must exist.
2339</p>
2340
2341<p>
2342The sixth member operator returns the value of element off. For example:
2343</p>
2344
2345<blockquote><pre>valarray&lt;char&gt; v0("abcdefghijklmnop", 16);
2346// v0[3] returns 'd'
2347</pre></blockquote>
2348
2349<p>
2350The seventh member operator returns an object of class <tt>valarray&lt;Ty&gt;</tt>
2351containing those elements of the controlled sequence designated by <tt>slicearr</tt>.
2352For example:
2353</p>
2354
2355<blockquote><pre>valarray&lt;char&gt; v0("abcdefghijklmnop", 16);
2356// v0[slice(2, 5, 3)] returns valarray&lt;char&gt;("cfilo", 5)
2357</pre></blockquote>
2358
2359<p>
2360The eighth member operator selects those elements of the controlled sequence
2361designated by <tt>gslicearr</tt>. For example:
2362</p>
2363
2364<blockquote><pre>valarray&lt;char&gt; v0("abcdefghijklmnop", 16);
2365const size_t lv[] = {2, 3};
2366const size_t dv[] = {7, 2};
2367const valarray&lt;size_t&gt; len(lv, 2), str(dv, 2);
2368// v0[gslice(3, len, str)] returns
2369//    valarray&lt;char&gt;("dfhkmo", 6)
2370</pre></blockquote>
2371
2372<p>
2373The ninth member operator selects those elements of the controlled sequence
2374designated by <tt>boolarr</tt>. For example:
2375</p>
2376
2377<blockquote><pre>valarray&lt;char&gt; v0("abcdefghijklmnop", 16);
2378const bool vb[] = {false, false, true, true, false, true};
2379// v0[valarray&lt;bool&gt;(vb, 6)] returns
2380//    valarray&lt;char&gt;("cdf", 3)
2381</pre></blockquote>
2382
2383<p>
2384The last member operator selects those elements of the controlled sequence
2385designated by <tt>indarr</tt>. For example:
2386</p>
2387
2388<blockquote><pre>valarray&lt;char&gt; v0("abcdefghijklmnop", 16);
2389const size_t vi[] = {7, 5, 2, 3, 8};
2390// v0[valarray&lt;size_t&gt;(vi, 5)] returns
2391//    valarray&lt;char&gt;("hfcdi", 5)
2392</pre></blockquote>
2393
2394</blockquote>
2395
2396
2397
2398
2399
2400<hr>
2401<h3><a name="446"></a>446. Iterator equality between different containers</h3>
2402<p><b>Section:</b> 24.2 [iterator.requirements], 23.2 [container.requirements] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
2403 <b>Submitter:</b> Andy Koenig <b>Opened:</b> 2003-12-16  <b>Last modified:</b> 2009-11-03</p>
2404<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#iterator.requirements">active issues</a> in [iterator.requirements].</p>
2405<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#iterator.requirements">issues</a> in [iterator.requirements].</p>
2406<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
2407<p><b>Discussion:</b></p>
2408<p>
2409What requirements does the standard place on equality comparisons between
2410iterators that refer to elements of different containers.  For example, if
2411v1 and v2 are empty vectors, is v1.end() == v2.end() allowed to yield true?
2412Is it allowed to throw an exception?
2413</p>
2414
2415<p>
2416The standard appears to be silent on both questions.
2417</p>
2418<p><i>[Sydney: The intention is that comparing two iterators from
2419different containers is undefined, but it's not clear if we say that,
2420or even whether it's something we should be saying in clause 23 or in
2421clause 24.  Intuitively we might want to say that equality is defined
2422only if one iterator is reachable from another, but figuring out how
2423to say it in any sensible way is a bit tricky: reachability is defined
2424in terms of equality, so we can't also define equality in terms of
2425reachability.
2426]</i></p>
2427
2428
2429<p><i>[
24302009-07 Frankfurt
2431]</i></p>
2432
2433
2434<blockquote>
2435Daniel volunteered to work on this.
2436</blockquote>
2437
2438<p><i>[
24392009-09-20 Daniel provided wording.
2440]</i></p>
2441
2442
2443<p><i>[
24442009-10 Santa Cruz:
2445]</i></p>
2446
2447
2448<blockquote>
2449Leave as Open. Alisdair has volunteered to refine the wording.
2450</blockquote>
2451
2452
2453
2454<p><b>Proposed resolution:</b></p>
2455<p>
2456Insert a new paragraph between 24.2 [iterator.requirements]/7+8:
2457</p>
2458
2459<blockquote>
2460<p>
2461[..] The result of the application of functions in the library to invalid
2462ranges is undefined.
2463</p>
2464
2465<p><ins>The result of directly or indirectly evaluating any comparison function
2466or the binary - operator with two iterator values as arguments that
2467were obtained
2468from two different ranges <tt>r1</tt> and <tt>r2</tt> (including their past-the-end values) which
2469are not subranges of one common range is undefined, unless explicitly
2470described otherwise.</ins>
2471</p>
2472
2473</blockquote>
2474
2475
2476
2477
2478
2479
2480<hr>
2481<h3><a name="471"></a>471. result of what() implementation-defined</h3>
2482<p><b>Section:</b> 18.8.1 [exception] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
2483 <b>Submitter:</b> Martin Sebor <b>Opened:</b> 2004-06-28  <b>Last modified:</b> 2009-10-26</p>
2484<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
2485<p><b>Discussion:</b></p>
2486
2487<p>[lib.exception] specifies the following:</p>
2488<pre>    exception (const exception&amp;) throw();
2489    exception&amp; operator= (const exception&amp;) throw();
2490
2491    -4- Effects: Copies an exception object.
2492    -5- Notes: The effects of calling what() after assignment
2493        are implementation-defined.
2494</pre>
2495
2496<p>
2497First, does the Note only apply to the assignment operator? If so,
2498what are the effects of calling what() on a copy of an object? Is
2499the returned pointer supposed to point to an identical copy of
2500the NTBS returned by what() called on the original object or not?
2501</p>
2502
2503<p>
2504Second, is this Note intended to extend to all the derived classes
2505in section 19? I.e., does the standard provide any guarantee for
2506the effects of what() called on a copy of any of the derived class
2507described in section 19?
2508</p>
2509
2510<p>
2511Finally, if the answer to the first question is no, I believe it
2512constitutes a defect since throwing an exception object typically
2513implies invoking the copy ctor on the object. If the answer is yes,
2514then I believe the standard ought to be clarified to spell out
2515exactly what the effects are on the copy (i.e., after the copy
2516ctor was called).
2517</p>
2518
2519<p><i>[Redmond: Yes, this is fuzzy.  The issue of derived classes is
2520  fuzzy too.]</i></p>
2521
2522
2523<p><i>[
2524Batavia: Howard provided wording.
2525]</i></p>
2526
2527
2528<p><i>[
2529Bellevue:
2530]</i></p>
2531
2532
2533<blockquote>
2534<p>
2535Eric concerned this is unimplementable, due to nothrow guarantees.
2536Suggested implementation would involve reference counting.
2537</p>
2538<p>
2539Is the implied reference counting subtle enough to call out a note on
2540implementation? Probably not.
2541</p>
2542<p>
2543If reference counting required, could we tighten specification further
2544to require same pointer value? Probably an overspecification, especially
2545if exception classes defer evalutation of final string to calls to
2546what().
2547</p>
2548<p>
2549Remember issue moved open and not resolved at Batavia, but cannot
2550remember who objected to canvas a disenting opinion - please speak up if
2551you disagree while reading these minutes!
2552</p>
2553<p>
2554Move to Ready as we are accepting words unmodified.
2555</p>
2556</blockquote>
2557
2558<p><i>[
2559Sophia Antipolis:
2560]</i></p>
2561
2562
2563<blockquote>
2564The issue was pulled from Ready.  It needs to make clear that only homogenous copying
2565is intended to be supported, not coping from a derived to a base.
2566</blockquote>
2567
2568<p><i>[
2569Batavia (2009-05):
2570]</i></p>
2571
2572<blockquote>
2573<p>
2574Howard supplied the following replacement wording
2575for paragraph 7 of the proposed resolution:
2576</p>
2577<blockquote>
2578<ins>-7- <i>Postcondition:</i> <tt>what()</tt> shall return the same NTBS
2579  as would be obtained by using <tt>static_cast</tt>
2580  to cast the rhs to the same types as the lhs
2581  and then calling <tt>what()</tt> on that possibly sliced object.</ins>
2582</blockquote>
2583<p>
2584Pete asks what "the same NTBS" means.
2585</p>
2586</blockquote>
2587
2588<p><i>[
25892009-07-30 Niels adds:
2590]</i></p>
2591
2592
2593<blockquote>
2594Further discussion in the thread starting with c++std-lib-24512.
2595</blockquote>
2596
2597<p><i>[
25982009-09-24 Niels provided updated wording:
2599]</i></p>
2600
2601
2602<blockquote>
2603<p>
2604I think the resolution should at least guarantee
2605that the result of <tt>what()</tt> is independent of whether the compiler does
2606copy-elision. And for any class derived from <tt>std::excepion</tt> that has a
2607constructor that allows specifying a <tt>what_arg</tt>, it should make sure that
2608the text of a user-provided <tt>what_arg</tt> is preserved, when the object is
2609copied. Note that all the implementations I've tested already appear to
2610satisfy the proposed resolution, including MSVC 2008 SP1, Apache
2611stdcxx-4.2.1, GCC 4.1.2, GCC 4.3.2, and CodeGear C++ 6.13.
2612</p>
2613<p>
2614The proposed resolution was updated with help from Daniel Kr�gler;
2615the update aims to clarify that the proposed postcondition only
2616applies to homogeneous copying.
2617</p>
2618</blockquote>
2619
2620<p><i>[
26212009-10 Santa Cruz:
2622]</i></p>
2623
2624
2625<blockquote>
2626Moved to Ready after inserting "publicly accessible" in two places.
2627</blockquote>
2628
2629
2630
2631<p><b>Proposed resolution:</b></p>
2632
2633<p>
2634Change 18.8.1 [exception] to:
2635</p>
2636
2637<blockquote>
2638<p>
2639-1- The class <tt>exception</tt> defines the base class for the types of
2640objects thrown as exceptions by C++ standard library components, and
2641certain expressions, to report errors detected during program execution.
2642</p>
2643<p><ins>
2644Each standard library class <tt>T</tt> that derives from class
2645<tt>exception</tt> shall have a publicly accessible copy constructor and a publicly accessible copy assignment
2646operator that do not exit with an exception. These member functions
2647shall preserve the following postcondition: If two objects <i>lhs</i>
2648and <i>rhs</i> both have dynamic type <tt>T</tt>, and <i>lhs</i> is a
2649copy of <i>rhs</i>, then <tt>strcmp(<i>lhs</i>.what(),
2650<i>rhs</i>.what()) == 0</tt>.
2651</ins></p>
2652<p>
2653 ...
2654</p>
2655
2656<pre>exception(const exception&amp; <ins>rhs</ins>) throw();
2657exception&amp; operator=(const exception&amp; <ins>rhs</ins>) throw();</pre>
2658
2659<blockquote>
2660<p>
2661-4- <i>Effects:</i> Copies an exception object.
2662</p>
2663<p>
2664<del> -5- <i>Remarks:</i> The effects of calling <tt>what()</tt> after assignment
2665are implementation-defined.</del>
2666</p>
2667<p>
2668<ins>-5- <i>Postcondition:</i>
2669	If <tt>*this</tt>
2670	and <i>rhs</i> both have dynamic type <tt>exception</tt>
2671	then <tt>strcmp(what(), <i>rhs</i>.what()) == 0</tt>.</ins>
2672</p>
2673
2674</blockquote>
2675
2676</blockquote>
2677
2678
2679
2680
2681
2682<hr>
2683<h3><a name="473"></a>473. underspecified ctype calls</h3>
2684<p><b>Section:</b> 22.4.1.1 [locale.ctype] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
2685 <b>Submitter:</b> Martin Sebor <b>Opened:</b> 2004-07-01  <b>Last modified:</b> 2009-10-21</p>
2686<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
2687<p><b>Discussion:</b></p>
2688<p>
2689Most ctype member functions come in two forms: one that operates
2690on a single character at a time and another form that operates
2691on a range of characters. Both forms are typically described by
2692a single Effects and/or Returns clause.
2693</p>
2694<p>
2695The Returns clause of each of the single-character non-virtual forms
2696suggests that the function calls the corresponding single character
2697virtual function, and that the array form calls the corresponding
2698virtual array form. Neither of the two forms of each virtual member
2699function is required to be implemented in terms of the other.
2700</p>
2701<p>
2702There are three problems:
2703</p>
2704<p>
27051. One is that while the standard does suggest that each non-virtual
2706member function calls the corresponding form of the virtual function,
2707it doesn't actually explicitly require it.
2708</p>
2709<p>
2710Implementations that cache results from some of the virtual member
2711functions for some or all values of their arguments might want to
2712call the array form from the non-array form the first time to fill
2713the cache and avoid any or most subsequent virtual calls. Programs
2714that rely on each form of the virtual function being called from
2715the corresponding non-virtual function will see unexpected behavior
2716when using such implementations.
2717</p>
2718<p>
27192. The second problem is that either form of each of the virtual
2720functions can be overridden by a user-defined function in a derived
2721class to return a value that is different from the one produced by
2722the virtual function of the alternate form that has not been
2723overriden.
2724</p>
2725<p>
2726Thus, it might be possible for, say, ctype::widen(c) to return one
2727value, while for ctype::widen(&amp;c, &amp;c + 1, &amp;wc) to set
2728wc to another value. This is almost certainly not intended. Both
2729forms of every function should be required to return the same result
2730for the same character, otherwise the same program using an
2731implementation that calls one form of the functions will behave
2732differently than when using another implementation that calls the
2733other form of the function "under the hood."
2734</p>
2735<p>
27363. The last problem is that the standard text fails to specify whether
2737one form of any of the virtual functions is permitted to be implemented
2738in terms of the other form or not, and if so, whether it is required
2739or permitted to call the overridden virtual function or not.
2740</p>
2741<p>
2742Thus, a program that overrides one of the virtual functions so that
2743it calls the other form which then calls the base member might end
2744up in an infinite loop if the called form of the base implementation
2745of the function in turn calls the other form.
2746</p>
2747<p>
2748Lillehammer: Part of this isn't a real problem. We already talk about
2749caching. 22.1.1/6 But part is a real problem. ctype virtuals may call
2750each other, so users don't know which ones to override to avoid avoid
2751infinite loops.</p>
2752
2753<p>This is a problem for all facet virtuals, not just ctype virtuals,
2754so we probably want a blanket statement in clause 22 for all
2755facets. The LWG is leaning toward a blanket prohibition, that a
2756facet's virtuals may never call each other. We might want to do that
2757in clause 27 too, for that matter. A review is necessary.  Bill will
2758provide wording.</p>
2759
2760<p><i>[
27612009-07 Frankfurt, Howard provided wording directed by consensus.
2762]</i></p>
2763
2764
2765<p><i>[
27662009-10 Santa Cruz:
2767]</i></p>
2768
2769
2770<blockquote>
2771Move to Ready.
2772</blockquote>
2773
2774
2775
2776<p><b>Proposed resolution:</b></p>
2777<p>
2778Add paragraph 3 to 22.4 [locale.categories]:
2779</p>
2780
2781<blockquote><ins>
2782-3- Within this clause it is unspecified if one virtual function calls another
2783virtual function.
2784</ins></blockquote>
2785
2786
2787
2788<p><b>Rationale:</b></p>
2789<p>
2790We are explicitly not addressing bullet
2791item #2, thus giving implementors more latitude. Users will have to
2792override both virtual functions, not just one.
2793</p>
2794
2795
2796
2797
2798<hr>
2799<h3><a name="485"></a>485. output iterator insufficiently constrained</h3>
2800<p><b>Section:</b> 24.2.2 [output.iterators] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
2801 <b>Submitter:</b> Chris Jefferson <b>Opened:</b> 2004-10-13  <b>Last modified:</b> 2009-10-26</p>
2802<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#output.iterators">issues</a> in [output.iterators].</p>
2803<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
2804<p><b>Discussion:</b></p>
2805<p>
2806The note on 24.1.2 Output iterators insufficiently limits what can be
2807performed on output iterators. While it requires that each iterator is
2808progressed through only once and that each iterator is written to only
2809once, it does not require the following things:</p>
2810
2811<p>Note: Here it is assumed that x is an output iterator of type X which
2812has not yet been assigned to.</p>
2813
2814<p>a) That each value of the output iterator is written to:
2815The standard allows:
2816++x; ++x; ++x;
2817</p>
2818
2819<p>
2820b) That assignments to the output iterator are made in order
2821X a(x); ++a; *a=1; *x=2; is allowed
2822</p>
2823
2824<p>
2825c) Chains of output iterators cannot be constructed:
2826X a(x); ++a; X b(a); ++b; X c(b); ++c; is allowed, and under the current
2827wording (I believe) x,a,b,c could be written to in any order.
2828</p>
2829
2830<p>I do not believe this was the intension of the standard?</p>
2831<p><i>[Lillehammer: Real issue.  There are lots of constraints we
2832  intended but didn't specify.  Should be solved as part of iterator
2833  redesign.]</i></p>
2834
2835
2836<p><i>[
28372009-07 Frankfurt
2838]</i></p>
2839
2840
2841<blockquote>
2842Bill provided wording according to consensus.
2843</blockquote>
2844
2845<p><i>[
28462009-07-21 Alisdair requests change from Review to Open.  See thread starting
2847with c++std-lib-24459 for discussion.
2848]</i></p>
2849
2850
2851<p><i>[
28522009-10 Santa Cruz:
2853]</i></p>
2854
2855
2856<blockquote>
2857Modified wording.  Set to Review.
2858</blockquote>
2859
2860<p><i>[
28612009-10 Santa Cruz:
2862]</i></p>
2863
2864
2865<blockquote>
2866Move to Ready after looking at again in a larger group in Santa Cruz.
2867</blockquote>
2868
2869
2870
2871<p><b>Proposed resolution:</b></p>
2872<p>
2873Change Table 101 &#8212; Output iterator requirements in 24.2.2 [output.iterators]:
2874</p>
2875<blockquote>
2876<table border="1">
2877<caption>Table 101 &#8212; Output iterator requirements</caption>
2878<tbody><tr>
2879<th>Expression</th>
2880<th>Return type</th>
2881<th>Operational semantics</th>
2882<th>Assertion/note pre-/post-condition</th>
2883</tr>
2884
2885<tr>
2886<td>
2887<tt>X(a)</tt>
2888</td>
2889<td>
2890&nbsp;
2891</td>
2892<td>
2893&nbsp;
2894</td>
2895<td>
2896<tt>a = t</tt> is equivalent to <tt>X(a) = t</tt>. note: a destructor is assumed.
2897</td>
2898</tr>
2899
2900<tr>
2901<td>
2902<tt>X u(a);</tt><br>
2903<tt>X u = a;</tt>
2904</td>
2905<td>
2906&nbsp;
2907</td>
2908<td>
2909&nbsp;
2910</td>
2911<td>
2912&nbsp;
2913</td>
2914</tr>
2915
2916<tr>
2917<td>
2918<tt>*r = o</tt>
2919</td>
2920<td>
2921result is not used
2922</td>
2923<td>
2924&nbsp;
2925</td>
2926<td>
2927<ins>
2928Post: <tt>r</tt> is not required to be dereferenceable.  <tt>r</tt> is incrementable.
2929</ins>
2930</td>
2931</tr>
2932
2933<tr>
2934<td>
2935<tt>++r</tt>
2936</td>
2937<td>
2938<tt>X&amp;</tt>
2939</td>
2940<td>
2941&nbsp;
2942</td>
2943<td>
2944<tt>&amp;r == &amp;++r</tt>
2945<ins>
2946Post: <tt>r</tt> is dereferenceable, unless otherwise specified.  <tt>r</tt> is not required to be incrementable.
2947</ins>
2948</td>
2949</tr>
2950
2951<tr>
2952<td>
2953<tt>r++</tt>
2954</td>
2955<td>
2956convertible to <tt>const X&amp;</tt>
2957</td>
2958<td>
2959<tt>{X tmp = r;<br>++r;<br>return tmp;}</tt>
2960</td>
2961<td>
2962<ins>
2963Post: <tt>r</tt> is dereferenceable, unless otherwise specified. <tt>r</tt> is not required to be incrementable.
2964</ins>
2965</td>
2966</tr>
2967
2968<tr>
2969<td>
2970<tt>*r++ = o;</tt>
2971</td>
2972<td>
2973result is not used
2974</td>
2975<td>
2976&nbsp;
2977</td>
2978<td>
2979
2980</td>
2981</tr>
2982
2983</tbody></table>
2984</blockquote>
2985
2986
2987
2988
2989
2990<hr>
2991<h3><a name="539"></a>539. partial_sum and adjacent_difference should mention requirements</h3>
2992<p><b>Section:</b> 26.7.3 [partial.sum] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
2993 <b>Submitter:</b> Marc Schoolderman <b>Opened:</b> 2006-02-06  <b>Last modified:</b> 2009-10-24</p>
2994<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
2995<p><b>Discussion:</b></p>
2996<p>
2997There are some problems in the definition of partial_sum and
2998adjacent_difference in 26.4 [lib.numeric.ops]
2999</p>
3000
3001<p>
3002Unlike <tt>accumulate</tt> and <tt>inner_product</tt>, these functions are not
3003parametrized on a "type T", instead, 26.4.3 [lib.partial.sum] simply
3004specifies the effects clause as;
3005</p>
3006
3007<blockquote><p>
3008Assigns to every element referred to by iterator <tt>i</tt> in the range
3009<tt>[result,result + (last - first))</tt> a value correspondingly equal to
3010</p>
3011<blockquote><pre>((...(* first + *( first + 1)) + ...) + *( first + ( i - result )))
3012</pre></blockquote>
3013</blockquote>
3014
3015<p>
3016And similarly for BinaryOperation. Using just this definition, it seems
3017logical to expect that:
3018</p>
3019
3020
3021<blockquote><pre>char i_array[4] = { 100, 100, 100, 100 };
3022int  o_array[4];
3023
3024std::partial_sum(i_array, i_array+4, o_array);
3025</pre></blockquote>
3026
3027<p>
3028Is equivalent to
3029</p>
3030
3031<blockquote><pre>int o_array[4] = { 100, 100+100, 100+100+100, 100+100+100+100 };
3032</pre></blockquote>
3033
3034<p>
3035i.e. 100, 200, 300, 400, with addition happening in the <tt>result type</tt>,
3036<tt>int</tt>.
3037</p>
3038
3039<p>
3040Yet all implementations I have tested produce 100, -56, 44, -112,
3041because they are using an accumulator of the <tt>InputIterator</tt>'s
3042<tt>value_type</tt>, which in this case is <tt>char</tt>, not <tt>int</tt>.
3043</p>
3044
3045<p>
3046The issue becomes more noticeable when the result of the expression <tt>*i +
3047*(i+1)</tt> or <tt>binary_op(*i, *i-1)</tt> can't be converted to the
3048<tt>value_type</tt>. In a contrived example:
3049</p>
3050
3051<blockquote><pre>enum not_int { x = 1, y = 2 };
3052...
3053not_int e_array[4] = { x, x, y, y };
3054std::partial_sum(e_array, e_array+4, o_array);
3055</pre></blockquote>
3056
3057<p>
3058Is it the intent that the operations happen in the <tt>input type</tt>, or in
3059the <tt>result type</tt>?
3060</p>
3061
3062<p>
3063If the intent is that operations happen in the <tt>result type</tt>, something
3064like this should be added to the "Requires" clause of 26.4.3/4
3065[lib.partial.sum]:
3066</p>
3067
3068<blockquote><p>
3069The type of <tt>*i + *(i+1)</tt> or <tt>binary_op(*i, *(i+1))</tt> shall meet the
3070requirements of <tt>CopyConstructible</tt> (20.1.3) and <tt>Assignable</tt>
3071(23.1) types.
3072</p></blockquote>
3073
3074<p>
3075(As also required for <tt>T</tt> in 26.4.1 [lib.accumulate] and 26.4.2
3076[lib.inner.product].)
3077</p>
3078
3079<p>
3080The "auto initializer" feature proposed in
3081<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2005/n1894.pdf">N1894</a>
3082is not required to
3083implement <tt>partial_sum</tt> this way. The 'narrowing' behaviour can still be
3084obtained by using the <tt>std::plus&lt;&gt;</tt> function object.
3085</p>
3086
3087<p>
3088If the intent is that operations happen in the <tt>input type</tt>, then
3089something like this should be added instead;
3090</p>
3091
3092<blockquote><p>
3093The type of *first shall meet the requirements of
3094<tt>CopyConstructible</tt> (20.1.3) and <tt>Assignable</tt> (23.1) types.
3095The result of <tt>*i + *(i+1)</tt> or <tt>binary_op(*i, *(i+1))</tt> shall be
3096convertible to this type.
3097</p></blockquote>
3098
3099<p>
3100The 'widening' behaviour can then be obtained by writing a custom proxy
3101iterator, which is somewhat involved.
3102</p>
3103
3104<p>
3105In both cases, the semantics should probably be clarified.
3106</p>
3107
3108<p>
310926.4.4 [lib.adjacent.difference] is similarly underspecified, although
3110all implementations seem to perform operations in the 'result' type:
3111</p>
3112
3113<blockquote><pre>unsigned char i_array[4] = { 4, 3, 2, 1 };
3114int o_array[4];
3115
3116std::adjacent_difference(i_array, i_array+4, o_array);
3117</pre></blockquote>
3118
3119<p>
3120o_array is 4, -1, -1, -1 as expected, not 4, 255, 255, 255.
3121</p>
3122
3123<p>
3124In any case, <tt>adjacent_difference</tt> doesn't mention the requirements on the
3125<tt>value_type</tt>; it can be brought in line with the rest of 26.4
3126[lib.numeric.ops] by adding the following to 26.4.4/2
3127[lib.adjacent.difference]:
3128</p>
3129
3130<blockquote><p>
3131The type of <tt>*first</tt> shall meet the requirements of
3132<tt>CopyConstructible</tt> (20.1.3) and <tt>Assignable</tt> (23.1) types."
3133</p></blockquote>
3134<p><i>[
3135Berlin: Giving output iterator's value_types very controversial. Suggestion of
3136adding signatures to allow user to specify "accumulator".
3137]</i></p>
3138
3139
3140<p><i>[
3141Bellevue:
3142]</i></p>
3143
3144
3145<blockquote>
3146The intent of the algorithms is to perform their calculations using the type of the input iterator.
3147Proposed wording provided.
3148</blockquote>
3149
3150<p><i>[
3151Sophia Antipolis:
3152]</i></p>
3153
3154
3155<blockquote>
3156We did not agree that the proposed resolution was correct. For example,
3157when the arguments are types <tt>(float*, float*, double*)</tt>, the
3158highest-quality solution would use double as the type of the
3159accumulator. If the intent of the wording is to require that the type of
3160the accumulator must be the <tt>input_iterator</tt>'s <tt>value_type</tt>, the wording
3161should specify it.
3162</blockquote>
3163
3164<p><i>[
31652009-05-09 Alisdair adds:
3166]</i></p>
3167
3168
3169<blockquote>
3170<p>
3171Now that we have the facility, the 'best' accumulator type could probably be
3172deduced as:
3173</p>
3174<blockquote><pre>std::common_type&lt;InIter::value_type, OutIter::reference&gt;::type
3175</pre></blockquote>
3176<p>
3177This type would then have additional requirements of constructability and
3178incrementability/assignability.
3179</p>
3180<p>
3181If this extracting an accumulator type from a pair/set of iterators (with
3182additional requirements on that type) is a problem for multiple functions,
3183it might be worth extracting into a SharedAccumulator concept or similar.
3184</p>
3185<p>
3186I'll go no further in writing up wording now, until the group gives a
3187clearer indication of preferred direction.
3188</p>
3189</blockquote>
3190
3191<p><i>[
31922009-07 Frankfurt
3193]</i></p>
3194
3195
3196<blockquote>
3197The proposed resolution isn't quite right. For example, "the type of
3198*first" should be changed to "iterator::value_type" or similar. Daniel
3199volunteered to correct the wording.
3200</blockquote>
3201
3202<p><i>[
32032009-07-29 Daniel corrected wording.
3204]</i></p>
3205
3206
3207<p><i>[
32082009-10 Santa Cruz:
3209]</i></p>
3210
3211
3212<blockquote>
3213Move to Ready.
3214</blockquote>
3215
3216
3217
3218<p><b>Proposed resolution:</b></p>
3219
3220
3221
3222<ol>
3223<li>
3224<p>
3225Change 26.7.3 [partial.sum]/1 as indicated:
3226</p>
3227
3228<blockquote>
3229<p>
3230<i>Effects:</i> <ins>Let <tt>VT</tt> be <tt>InputIterator</tt>'s value type. For a nonempty range,
3231initializes an accumulator <tt>acc</tt> of type <tt>VT</tt> with <tt>*first</tt> and performs
3232<tt>*result = acc</tt>. For every iterator <tt>i</tt> in <tt>[first + 1, last)</tt> in order, <tt>acc</tt> is then
3233modified by <tt>acc = acc + *i</tt> or <tt>acc = binary_op(acc, *i)</tt> and is assigned
3234to <tt>*(result + (i - first))</tt>.</ins> <del>Assigns to every element referred to by
3235iterator <tt>i</tt> in the range <tt>[result,result + (last - first))</tt> a value
3236correspondingly
3237equal to</del>
3238</p>
3239
3240<blockquote><pre><del>
3241((...(*first + *(first + 1)) + ...) + *(first + (i - result)))
3242</del></pre></blockquote>
3243
3244<p><del>
3245or
3246</del></p>
3247
3248<blockquote><pre><del>
3249binary_op(binary_op(...,
3250   binary_op(*first, *(first + 1)),...), *(first + (i - result)))
3251</del></pre></blockquote>
3252</blockquote>
3253</li>
3254
3255<li>
3256<p>
3257Change 26.7.3 [partial.sum]/3 as indicated:
3258</p>
3259
3260<blockquote>
3261<i>Complexity:</i> Exactly <tt><ins>max(</ins>(last - first) - 1<ins>, 0)</ins></tt>
3262applications
3263of <tt><del>binary_op</del></tt><ins>the binary operation</ins>.
3264</blockquote>
3265</li>
3266
3267<li>
3268<p>
3269Change 26.7.3 [partial.sum]/4 as indicated:
3270</p>
3271
3272<blockquote>
3273<i>Requires:</i> <ins><tt>VT</tt> shall be constructible from the type of <tt>*first</tt>, the result of
3274<tt>acc + *i</tt> or <tt>binary_op(acc, *i)</tt> shall be implicitly convertible to <tt>VT</tt>, and
3275the result of the expression <tt>acc</tt> shall be writable to the <tt>result</tt>
3276output iterator.</ins> In the ranges <tt>[first,last]</tt> and
3277<tt>[result,result + (last - first)]</tt> [..]
3278</blockquote>
3279</li>
3280
3281<li>
3282<p>
3283Change 26.7.4 [adjacent.difference]/1 as indicated:
3284</p>
3285
3286<blockquote>
3287<p>
3288<i>Effects:</i> <ins>Let <tt>VT</tt> be <tt>InputIterator</tt>'s value type. For a nonempty range,
3289initializes an accumulator <tt>acc</tt> of type <tt>VT</tt> with <tt>*first</tt> and performs
3290<tt>*result = acc</tt>. For every iterator <tt>i</tt> in <tt>[first + 1, last)</tt> in order,
3291initializes a
3292value <tt>val</tt> of type <tt>VT</tt> with <tt>*i</tt>, assigns the result of <tt>val - acc</tt> or
3293<tt>binary_op(val, acc)</tt>
3294to <tt>*(result + (i - first))</tt> and modifies <tt>acc = std::move(val)</tt>.</ins>
3295<del>Assigns to every element referred to by iterator <tt>i</tt> in the range
3296<tt>[result + 1,
3297result + (last - first))</tt> a value correspondingly equal to</del>
3298</p>
3299
3300<blockquote><pre><del>
3301*(first + (i - result)) - *(first + (i - result) - 1)
3302</del></pre></blockquote>
3303
3304<p><del>
3305or
3306</del></p>
3307
3308<blockquote><pre><del>
3309binary_op(*(first + (i - result)), *(first + (i - result) - 1)).
3310</del></pre></blockquote>
3311
3312<p><del>
3313result gets the value of *first.</del>
3314</p>
3315</blockquote>
3316</li>
3317
3318<li>
3319<p>
3320Change 26.7.4 [adjacent.difference]/2 as indicated:
3321</p>
3322
3323<blockquote>
3324<i>Requires:</i> <ins><tt>VT</tt> shall be <tt>MoveAssignable</tt> ([moveassignable])
3325and shall be
3326constructible from the type of <tt>*first</tt>. The result
3327of the expression <tt>acc</tt> and the result of the expression <tt>val - acc</tt> or
3328<tt>binary_op(val, acc)</tt>
3329shall be writable to the <tt>result</tt> output iterator.</ins> In the ranges
3330<tt>[first,last]</tt> [..]
3331</blockquote>
3332</li>
3333
3334<li>
3335<p>
3336Change 26.7.4 [adjacent.difference]/5 as indicated:
3337</p>
3338
3339<blockquote>
3340<i>Complexity:</i> Exactly <tt><ins>max(</ins>(last - first) - 1<ins>, 0)</ins></tt>
3341applications
3342of <del><tt>binary_op</tt></del><ins>the binary operation</ins>.
3343</blockquote>
3344</li>
3345</ol>
3346
3347
3348
3349
3350
3351
3352
3353
3354<hr>
3355<h3><a name="556"></a>556. is Compare a BinaryPredicate?</h3>
3356<p><b>Section:</b> 25.4 [alg.sorting] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Review">Review</a>
3357 <b>Submitter:</b> Martin Sebor <b>Opened:</b> 2006-02-05  <b>Last modified:</b> 2009-10-25</p>
3358<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#alg.sorting">issues</a> in [alg.sorting].</p>
3359<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Review">Review</a> status.</p>
3360<p><b>Discussion:</b></p>
3361<p>
3362In 25, p8 we allow BinaryPredicates to return a type that's convertible
3363to bool but need not actually be bool. That allows predicates to return
3364things like proxies and requires that implementations be careful about
3365what kinds of expressions they use the result of the predicate in (e.g.,
3366the expression in if (!pred(a, b)) need not be well-formed since the
3367negation operator may be inaccessible or return a type that's not
3368convertible to bool).
3369</p>
3370<p>
3371Here's the text for reference:
3372</p>
3373<blockquote><p>
3374  ...if an algorithm takes BinaryPredicate binary_pred as its argument
3375 and first1 and first2 as its iterator arguments, it should work
3376 correctly in the construct if (binary_pred(*first1, first2)){...}.
3377</p></blockquote>
3378
3379<p>
3380In 25.3, p2 we require that the Compare function object return true
3381of false, which would seem to preclude such proxies. The relevant text
3382is here:
3383</p>
3384<blockquote><p>
3385  Compare is used as a function object which returns true if the first
3386  argument is less than the second, and false otherwise...
3387</p></blockquote>
3388
3389<p><i>[
3390Portland:  Jack to define "convertible to bool" such that short circuiting isn't
3391destroyed.
3392]</i></p>
3393
3394
3395<p><i>[
33962009-07-28 Reopened by Alisdair.  No longer solved by concepts.
3397]</i></p>
3398
3399
3400<p><i>[
34012009-10 Santa Cruz:
3402]</i></p>
3403
3404
3405<blockquote>
3406Move to Review once wording received. Stefanus to send proposed wording.
3407</blockquote>
3408
3409<p><i>[
34102009-10 Santa Cruz:
3411]</i></p>
3412
3413
3414<blockquote>
3415Move to Review once wording received. Stefanus to send proposed wording.
3416</blockquote>
3417
3418<p><i>[
34192009-10-24 Stefanus supplied wording.
3420]</i></p>
3421
3422
3423<blockquote>
3424Move to Review once wording received. Stefanus to send proposed wording.
3425Current proposed wording proposed here:
3426<blockquote>
3427<p>
3428I think we could fix this by rewording 25.3, p2 to read somthing like:
3429</p>
3430<blockquote><p>
3431-2- <tt>Compare</tt> is <del>used as a function object which returns
3432<tt>true</tt> if the first argument</del> <ins>a <tt>BinaryPredicate</tt>. The
3433return value of the function call operator applied to an object of type
3434<tt>Compare</tt>, when converted to type <tt>bool</tt>, yields <tt>true</tt>
3435if the first argument of the call</ins> is less than the second, and
3436<tt>false</tt> otherwise. <tt>Compare <i>comp</i></tt> is used throughout for
3437algorithms assuming an ordering relation. It is assumed that <tt><i>comp</i></tt>
3438will not apply any non-constant function through the dereferenced iterator.
3439</p></blockquote>
3440</blockquote>
3441</blockquote>
3442
3443
3444
3445<p><b>Proposed resolution:</b></p>
3446<p>
3447Change 25.4 [alg.sorting] p2:
3448</p>
3449<blockquote>
3450<tt>Compare</tt> is used as a function object<ins>. The return value of
3451the function call operator applied to an object of type Compare, when
3452converted to type bool, yields true if the first argument of the
3453call</ins> <del>which returns <tt>true</tt> if the first argument</del>
3454is less than the second, and <tt>false</tt> otherwise. <tt>Compare
3455comp</tt> is used throughout for algorithms assuming an ordering
3456relation. It is assumed that <tt>comp</tt> will not apply any
3457non-constant function through the dereferenced iterator.
3458</blockquote>
3459
3460
3461<p><b>Rationale:</b></p>
3462<p><i>[
3463San Francisco:
3464]</i></p>
3465
3466
3467<blockquote>
3468Solved by
3469(<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2774.pdf">N2774</a>).
3470</blockquote>
3471
3472
3473
3474
3475
3476
3477<hr>
3478<h3><a name="594"></a>594. Disadvantages of defining Swappable in terms of CopyConstructible and Assignable</h3>
3479<p><b>Section:</b> 20.2.1 [utility.arg.requirements] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
3480 <b>Submitter:</b> Niels Dekker <b>Opened:</b> 2006-11-02  <b>Last modified:</b> 2009-11-08</p>
3481<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#utility.arg.requirements">active issues</a> in [utility.arg.requirements].</p>
3482<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#utility.arg.requirements">issues</a> in [utility.arg.requirements].</p>
3483<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
3484<p><b>Discussion:</b></p>
3485<p>
3486It seems undesirable to define the Swappable requirement in terms of
3487CopyConstructible and Assignable requirements. And likewise, once the
3488MoveConstructible and MoveAssignable requirements (N1860) have made it
3489into the Working Draft, it seems undesirable to define the Swappable
3490requirement in terms of those requirements. Instead, it appears
3491preferable to have the Swappable requirement defined exclusively in
3492terms of the existence of an appropriate swap function.
3493</p>
3494<p>
3495Section 20.1.4 [lib.swappable] of the current Working Draft (N2009)
3496says:
3497</p>
3498<blockquote><p>
3499The Swappable requirement is met by satisfying one or more of the
3500following conditions:</p>
3501<ul>
3502<li>
3503T is Swappable if T satisfies the CopyConstructible requirements
3504(20.1.3) and the Assignable requirements (23.1);
3505</li>
3506<li>
3507T is Swappable if a namespace scope function named swap exists in the
3508same namespace as the definition of T, such that the expression
3509swap(t,u) is valid and has the semantics described in Table 33.
3510</li>
3511</ul>
3512</blockquote>
3513<p>
3514I can think of three disadvantages of this definition:
3515</p>
3516<ol>
3517<li>
3518<p>
3519If a client's type T satisfies the first condition (T is both
3520CopyConstructible and Assignable), the client cannot stop T from
3521satisfying the Swappable requirement without stopping T from
3522satisfying the first condition.
3523</p>
3524<p>
3525A client might want to stop T from satisfying the Swappable
3526requirement, because swapping by means of copy construction and
3527assignment might throw an exception, and she might find a throwing
3528swap unacceptable for her type. On the other hand, she might not feel
3529the need to fully implement her own swap function for this type. In
3530this case she would want to be able to simply prevent algorithms that
3531would swap objects of type T from being used, e.g., by declaring a
3532swap function for T, and leaving this function purposely undefined.
3533This would trigger a link error, if an attempt would be made to use
3534such an algorithm for this type. For most standard library
3535implementations, this practice would indeed have the effect of
3536stopping T from satisfying the Swappable requirement.
3537</p>
3538</li>
3539<li>
3540<p>
3541A client's type T that does not satisfy the first condition can not be
3542made Swappable by providing a specialization of std::swap for T.
3543</p>
3544<p>
3545While I'm aware about the fact that people have mixed feelings about
3546providing a specialization of std::swap, it is well-defined to do so.
3547It sounds rather counter-intuitive to say that T is not Swappable, if
3548it has a valid and semantically correct specialization of std::swap.
3549Also in practice, providing such a specialization will have the same
3550effect as satisfying the Swappable requirement.
3551</p>
3552</li>
3553<li>
3554<p>
3555For a client's type T that satisfies both conditions of the Swappable
3556requirement, it is not specified which of the two conditions prevails.
3557After reading section 20.1.4 [lib.swappable], one might wonder whether
3558objects of T will be swapped by doing copy construction and
3559assignments, or by calling the swap function of T.
3560</p>
3561<p>
3562I'm aware that the intention of the Draft is to prefer calling the
3563swap function of T over doing copy construction and assignments. Still
3564in my opinion, it would be better to make this clear in the wording of
3565the definition of Swappable. 
3566</p>
3567</li>
3568</ol>
3569<p>
3570I would like to have the Swappable requirement defined in such a way
3571that the following code fragment will correctly swap two objects of a
3572type T, if and only if T is Swappable:
3573</p>
3574<pre>   using std::swap;
3575   swap(t, u);  // t and u are of type T.
3576</pre>
3577<p>
3578This is also the way Scott Meyers recommends calling a swap function,
3579in Effective C++, Third Edition, item 25.
3580</p>
3581<p>
3582Most aspects of this issue have been dealt with in a discussion on
3583comp.std.c++ about the Swappable requirement, from 13 September to 4
3584October 2006, including valuable input by David Abrahams, Pete Becker,
3585Greg Herlihy, Howard Hinnant and others.
3586</p>
3587
3588<p><i>[
3589San Francisco:
3590]</i></p>
3591
3592
3593<blockquote>
3594Recommend NAD.  Solved by
3595<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2774.pdf">N2774</a>.
3596</blockquote>
3597
3598<p><i>[
35992009-07 Frankfurt
3600]</i></p>
3601
3602
3603<blockquote>
3604Moved to Open.  Waiting for non-concepts draft.
3605</blockquote>
3606
3607<p><i>[
36082009-11-08 Howard adds:
3609]</i></p>
3610
3611
3612<blockquote>
3613This issue is very closely related to <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#742">742</a>.
3614</blockquote>
3615
3616
3617<p><b>Proposed resolution:</b></p>
3618<p>
3619Change section 20.1.4 [lib.swappable] as follows:
3620</p>
3621<blockquote><p>
3622The Swappable requirement is met by satisfying
3623<del>one or more of the following conditions:</del>
3624<ins>the following condition:</ins></p>
3625<ul>
3626
3627<li>
3628<del>T is Swappable if T satisfies the CopyConstructible requirements
3629(20.1.3) and the Assignable requirements (23.1);</del>
3630</li>
3631<li>
3632<del>
3633T is Swappable if a namespace scope function named swap exists in the
3634same namespace as the definition of T, such that the expression
3635swap(t,u) is valid and has the semantics described in Table 33.
3636</del>
3637T is Swappable if an unqualified function call swap(t,u) is valid
3638within the namespace std, and has the semantics described in Table 33.
3639</li>
3640</ul>
3641</blockquote>
3642
3643
3644
3645
3646
3647<hr>
3648<h3><a name="625"></a>625. mixed up <i>Effects</i> and <i>Returns</i> clauses</h3>
3649<p><b>Section:</b> 17 [library] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
3650 <b>Submitter:</b> Martin Sebor <b>Opened:</b> 2007-01-20  <b>Last modified:</b> 2009-10-20</p>
3651<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#library">active issues</a> in [library].</p>
3652<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#library">issues</a> in [library].</p>
3653<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
3654<p><b>Duplicate of:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#895">895</a></p>
3655<p><b>Discussion:</b></p>
3656 <p>
3657
3658Many member functions of <code>basic_string</code> are overloaded,
3659with some of the overloads taking a <code>string</code> argument,
3660others <code>value_type*</code>, others <code>size_type</code>, and
3661others still <code>iterators</code>. Often, the requirements on one of
3662the overloads are expressed in the form of <i>Effects</i>,
3663<i>Throws</i>, and in the Working Paper
3664(<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2006/n2134.pdf">N2134</a>)
3665also <i>Remark</i> clauses, while those on the rest of the overloads
3666via a reference to this overload and using a <i>Returns</i> clause.
3667</p>
3668
3669<p>
3670The difference between the two forms of specification is that per
367117.5.1.4 [structure.specifications], p3, an <i>Effects</i> clause specifies
3672<i>"actions performed by the functions,"</i> i.e., its observable
3673effects, while a <i>Returns</i> clause is <i>"a description of the
3674return value(s) of a function"</i> that does not impose any
3675requirements on the function's observable effects.
3676</p>
3677
3678<p>
3679Since only <i>Notes</i> are explicitly defined to be informative and
3680all other paragraphs are explicitly defined to be normative, like
3681<i>Effects</i> and <i>Returns</i>, the new <i>Remark</i> clauses also
3682impose normative requirements.
3683</p>
3684
3685<p>
3686So by this strict reading of the standard there are some member
3687functions of <code>basic_string</code> that are required to throw an
3688exception under some conditions or use specific traits members while
3689many other otherwise equivalent overloads, while obliged to return the
3690same values, aren't required to follow the exact same requirements
3691with regards to the observable effects.
3692</p>
3693
3694<p>
3695Here's an example of this problem that was precipitated by the change
3696from informative Notes to normative <i>Remark</i>s (presumably made to
3697address <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#424">424</a>):
3698</p>
3699
3700<p>
3701In the Working Paper, <code>find(string, size_type)</code> contains a
3702<i>Remark</i> clause (which is just a <i>Note</i> in the current
3703standard) requiring it to use <code>traits::eq()</code>.
3704</p>
3705
3706<p>
3707<code>find(const charT *s, size_type pos)</code> is specified to
3708return <code>find(string(s), pos)</code> by a <i>Returns</i> clause
3709and so it is not required to use <code>traits::eq()</code>. However,
3710the Working Paper has replaced the original informative <i>Note</i>
3711about the function using <code>traits::length()</code> with a
3712normative requirement in the form of a <i>Remark</i>. Calling
3713<code>traits::length()</code> may be suboptimal, for example when the
3714argument is a very long array whose initial substring doesn't appear
3715anywhere in <code>*this</code>.
3716</p>
3717
3718<p>
3719Here's another similar example, one that existed even prior to the
3720introduction of <i>Remark</i>s:
3721</p>
3722
3723<p>
3724<code> insert(size_type pos, string, size_type, size_type)</code> is
3725required to throw <code>out_of_range</code> if <code>pos &gt;
3726size()</code>.
3727</p>
3728
3729<p>
3730<code>insert(size_type pos, string str)</code> is specified to return
3731<code>insert(pos, str, 0, npos)</code> by a <i>Returns</i> clause and
3732so its effects when <code>pos &gt; size()</code> are strictly speaking
3733unspecified.
3734</p><p>
3735
3736</p>
3737I believe a careful review of the current <i>Effects</i> and
3738<i>Returns</i> clauses is needed in order to identify all such
3739problematic cases. In addition, a review of the Working Paper should
3740be done to make sure that the newly introduced normative <i>Remark</i>
3741clauses do not impose any undesirable normative requirements in place
3742of the original informative <i>Notes</i>.
3743
3744
3745<p><i>[
3746Batavia: Alan and Pete to work.
3747]</i></p>
3748
3749
3750<p><i>[
3751Bellevue: Marked as NAD Editorial.
3752]</i></p>
3753
3754
3755<p><i>[
3756Post-Sophia Antipolis:
3757Martin indicates there is still work to be done on this issue.
3758Reopened.
3759]</i></p>
3760
3761
3762<p><i>[
3763Batavia (2009-05):
3764]</i></p>
3765
3766<blockquote>
3767Tom proposes we say that, unless specified otherwise,
3768it is always the caller's responsibility to verify that supplied arguments
3769meet the called function's requirements.
3770If further semantics are specified
3771(e.g., that the function throws under certain conditions),
3772then it is up to the implementer to check those conditions.
3773Alan feels strongly that our current use of Requires in this context
3774is confusing, especially now that <tt>requires</tt> is a new keyword.
3775</blockquote>
3776
3777<p><i>[
37782009-07 Frankfurt
3779]</i></p>
3780
3781
3782<blockquote>
3783Move to Tentatively NAD.
3784</blockquote>
3785
3786<p><i>[
37872009 Santa Cruz:
3788]</i></p>
3789
3790
3791<blockquote>
3792Move to Open.  Martin will work on proposed wording.
3793</blockquote>
3794
3795
3796
3797<p><b>Proposed resolution:</b></p>
3798<p>
3799</p>
3800
3801
3802
3803
3804
3805<hr>
3806<h3><a name="631"></a>631. conflicting requirements for <tt>BinaryPredicate</tt></h3>
3807<p><b>Section:</b> 25 [algorithms] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Review">Review</a>
3808 <b>Submitter:</b> James Kanze <b>Opened:</b> 2007-01-31  <b>Last modified:</b> 2009-10-24</p>
3809<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#algorithms">active issues</a> in [algorithms].</p>
3810<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#algorithms">issues</a> in [algorithms].</p>
3811<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Review">Review</a> status.</p>
3812<p><b>Discussion:</b></p>
3813<p>
3814The general requirements for <tt><tt>BinaryPredicate</tt></tt> (in 25 [algorithms]/8) contradict the implied specific requirements for
3815some functions. In particular, it says that:
3816</p>
3817
3818<blockquote><p>
3819[...] if an algorithm takes <tt>BinaryPredicate <i>binary_pred</i></tt>
3820as its argument and <tt><i>first1</i></tt> and <i>first2</i> as its
3821iterator arguments, it should work correctly in the construct <tt>if
3822(binary_pred (*<i>first1</i> , *<i>first2</i> )){...}</tt>.
3823<tt>BinaryPredicate</tt> always takes the first iterator type as its
3824first argument, that is, in those cases when <tt>T <i>value</i></tt> is
3825part of the signature, it should work correctly in the context of <tt>if
3826(binary_pred (*<i>first1</i> , <i>value</i>)){...}</tt>.
3827</p></blockquote>
3828
3829<p>
3830In the description of <tt>upper_bound</tt> (25.4.3.2 [upper.bound]/2), however, the use is described as
3831"<tt>!comp(<i>value</i>, <i>e</i>)</tt>", where <tt><i>e</i></tt> is an
3832element of the sequence (a result of dereferencing
3833<tt>*<i>first</i></tt>).
3834</p>
3835
3836<p>
3837In the description of <tt>lexicographical_compare</tt>, we have both
3838"<tt>*<i>first1</i> &lt; *<i>first2</i></tt>" and "<tt>*<i>first2</i>
3839&lt; *<i>first1</i></tt>" (which presumably implies "<tt>comp(
3840*<i>first1</i>, *<i>first2</i> )</tt>" and "<tt>comp( *<i>first2</i>,
3841*<i>first1</i> )</tt>".
3842</p>
3843
3844<p><i>[
3845Toronto:  Moved to Open.  ConceptGCC seems to get <tt>lower_bound</tt>
3846and <tt>upper_bound</tt> to work withoutt these changes.
3847]</i></p>
3848
3849
3850<p><i>[
38512009-07-28 Reopened by Alisdair.  No longer solved by concepts.
3852]</i></p>
3853
3854
3855<p><i>[
38562009-10 Santa Cruz:
3857]</i></p>
3858
3859
3860<blockquote>
3861Move to Review. The small problem with the "iterator type"
3862will be fixed. The cited functions (<tt>lower_bound</tt>, <tt>uppwer_bound</tt>,
3863<tt>equal_range</tt>) don't actually use <tt>BinaryPredicate</tt> , and where it is used,
3864it is consistent with  [algorithm]/8, so the main complaint of the issue
3865is moot.
3866</blockquote>
3867
3868
3869
3870<p><b>Proposed resolution:</b></p>
3871<p>
3872Logically, the <tt>BinaryPredicate</tt> is used as an ordering
3873relationship, with the semantics of "less than".  Depending on the
3874function, it may be used to determine equality, or any of the inequality
3875relationships; doing this requires being able to use it with either
3876parameter first.  I would thus suggest that the requirement be:
3877</p>
3878
3879<blockquote><p>
3880[...] <tt>BinaryPredicate</tt> always takes the first iterator
3881<tt>value_type</tt> as one of its arguments, it is unspecified which. If
3882an algorithm takes <tt>BinaryPredicate <i>binary_pred</i></tt> as its
3883argument and <tt><i><i>first1</i></i></tt> and <i>first2</i> as its
3884iterator arguments, it should work correctly both in the construct
3885<tt>if (binary_pred (*<i>first1</i> , *<i>first2</i> )){...}</tt> and
3886<tt>if (binary_pred (*<i>first2</i>, *<i>first1</i>)){...}</tt>.  In
3887those cases when <tt>T <i>value</i></tt> is part of the signature, it
3888should work correctly in the context of <tt>if (binary_pred
3889(*<i>first1</i> , <i>value</i>)){...}</tt> and of <tt>if (binary_pred
3890(<i>value</i>, *<i>first1</i>)){...}</tt>. [<i>Note:</i> if the two
3891types are not identical, and neither is convertable to the other, this
3892may require that the <tt>BinaryPredicate</tt> be a functional object
3893with two overloaded <tt>operator()()</tt> functions. <i>--end note</i>]
3894</p></blockquote>
3895
3896<p>
3897Alternatively, one could specify an order for each function. IMHO, this
3898would be more work for the committee, more work for the implementors,
3899and of no real advantage for the user: some functions, such as
3900<tt>lexicographical_compare</tt> or <tt>equal_range</tt>, will still require both
3901functions, and it seems like a much easier rule to teach that both
3902functions are always required, rather than to have a complicated list of
3903when you only need one, and which one.
3904</p>
3905
3906
3907<p><b>Rationale:</b></p>
3908<p><i>[
3909post San Francisco:
3910]</i></p>
3911
3912
3913<blockquote>
3914Solved by
3915<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2759.pdf">N2759</a>.
3916</blockquote>
3917
3918
3919
3920
3921
3922
3923<hr>
3924<h3><a name="671"></a>671. precision of hexfloat</h3>
3925<p><b>Section:</b> 22.4.2.2.2 [facet.num.put.virtuals] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
3926 <b>Submitter:</b> John Salmon <b>Opened:</b> 2007-04-20  <b>Last modified:</b> 2009-10-21</p>
3927<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#facet.num.put.virtuals">active issues</a> in [facet.num.put.virtuals].</p>
3928<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#facet.num.put.virtuals">issues</a> in [facet.num.put.virtuals].</p>
3929<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
3930<p><b>Discussion:</b></p>
3931<p>
3932I am trying to understand how TR1 supports hex float (%a) output.
3933</p>
3934<p>
3935As far as I can tell, it does so via the following:
3936</p>
3937<p>
39388.15 Additions to header &lt;locale&gt; [tr.c99.locale]
3939</p>
3940<p>
3941In subclause 22.4.2.2.2 [facet.num.put.virtuals], Table 58 Floating-point conversions, after
3942the line:
3943floatfield == ios_base::scientific %E
3944</p>
3945<p>
3946add the two lines:
3947</p>
3948<blockquote><pre>floatfield == ios_base::fixed | ios_base::scientific &amp;&amp; !uppercase %a
3949floatfield == ios_base::fixed | ios_base::scientific %A 2
3950</pre></blockquote>
3951<p>
3952[Note: The additional requirements on print and scan functions, later
3953in this clause, ensure that the print functions generate hexadecimal
3954floating-point fields with a %a or %A conversion specifier, and that
3955the scan functions match hexadecimal floating-point fields with a %g
3956conversion specifier.  end note]
3957</p>
3958<p>
3959Following the thread, in 22.4.2.2.2 [facet.num.put.virtuals], we find:
3960</p>
3961<p>
3962For conversion from a floating-point type, if (flags &amp; fixed) != 0 or
3963if str.precision() &gt; 0, then str.precision() is specified in the
3964conversion specification.
3965</p>
3966<p>
3967This would seem to imply that when floatfield == fixed|scientific, the
3968precision of the conversion specifier is to be taken from
3969str.precision().  Is this really what's intended?  I sincerely hope
3970that I'm either missing something or this is an oversight.  Please
3971tell me that the committee did not intend to mandate that hex floats
3972(and doubles) should by default be printed as if by %.6a.
3973</p>
3974
3975<p><i>[
3976Howard: I think the fundamental issue we overlooked was that with %f,
3977%e, %g, the default precision was always 6.  With %a the default
3978precision is not 6, it is infinity.  So for the first time, we need to
3979distinguish between the default value of precision, and the precision
3980value 6.
3981]</i></p>
3982
3983
3984<p><i>[
39852009-07 Frankfurt
3986]</i></p>
3987
3988
3989<blockquote>
3990<p>
3991Leave this open for Robert and Daniel to work on.
3992</p>
3993<p>
3994Straw poll: Disposition?
3995</p>
3996<ul>
3997<li>Default is %.6a (i.e. NAD): 2</li>
3998<li>Always %a (no precision): 6</li>
3999<li>precision(-1) == %a: 3</li>
4000</ul>
4001<p>
4002Daniel and Robert have direction to write up wording for the "always %a" solution.
4003</p>
4004
4005<p><i>[
40062009-07-15 Robert provided wording.
4007]</i></p>
4008
4009</blockquote>
4010
4011<p><i>[
40122009-10 Santa Cruz:
4013]</i></p>
4014
4015
4016<blockquote>
4017Move to Ready.
4018</blockquote>
4019
4020
4021
4022<p><b>Proposed resolution:</b></p>
4023<p>
4024Change 22.4.2.2.2 [facet.num.put.virtuals], Stage 1, under p5 (near the end
4025of Stage 1):
4026</p>
4027
4028<blockquote>
4029For conversion from a floating-point type, <tt>str.precision()</tt> is specified
4030<ins>as precision</ins> in the conversion specification
4031<ins>if <tt>floatfield != (ios_base::fixed | ios_base::scientific)</tt>, else no
4032precision is specified</ins>.
4033</blockquote>
4034
4035
4036
4037<p><i>[
4038Kona (2007): Robert volunteers to propose wording.
4039]</i></p>
4040
4041
4042
4043
4044
4045<hr>
4046<h3><a name="676"></a>676. Moving the unordered containers</h3>
4047<p><b>Section:</b> 23.5 [unord] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Review">Review</a>
4048 <b>Submitter:</b> Howard Hinnant <b>Opened:</b> 2007-05-05  <b>Last modified:</b> 2009-10-29</p>
4049<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#unord">issues</a> in [unord].</p>
4050<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Review">Review</a> status.</p>
4051<p><b>Discussion:</b></p>
4052<p>
4053Move semantics are missing from the <tt>unordered</tt> containers.  The proposed
4054resolution below adds move-support consistent with
4055<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2005/n1858.html">N1858</a>
4056and the current working draft.
4057</p>
4058
4059<p>
4060The current proposed resolution simply lists the requirements for each function.
4061These might better be hoisted into the requirements table for unordered associative containers.
4062Futhermore a mild reorganization of the container requirements could well be in order.
4063This defect report is purposefully ignoring these larger issues and just focusing
4064on getting the unordered containers "moved".
4065</p>
4066
4067<p><i>[
40682009-07-28 Reopened by Alisdair.  No longer solved by concepts.
4069]</i></p>
4070
4071
4072<p><i>[
40732009-10-17 Removed rvalue-swaps from wording.
4074]</i></p>
4075
4076
4077<p><i>[
40782009-10 Santa Cruz:
4079]</i></p>
4080
4081
4082<blockquote>
4083Move to Review. Alisdair will review proposed wording.
4084</blockquote>
4085
4086<p><i>[
40872009-10-29 Daniel updates wording.
4088]</i></p>
4089
4090
4091
4092
4093<p><b>Proposed resolution:</b></p>
4094
4095<p><b><tt>unordered_map</tt></b></p>
4096
4097<p>
4098Change 23.5.1 [unord.map]:
4099</p>
4100
4101<blockquote><pre>class unordered_map
4102{
4103    ...
4104    unordered_map(const unordered_map&amp;);
4105    <ins>unordered_map(unordered_map&amp;&amp;);</ins>
4106    ~unordered_map();
4107    unordered_map&amp; operator=(const unordered_map&amp;);
4108    <ins>unordered_map&amp; operator=(unordered_map&amp;&amp;);</ins>
4109    ...
4110    // modifiers 
4111    <del>std::</del>pair&lt;iterator, bool&gt; insert(const value_type&amp; obj); 
4112    <ins>template &lt;class P&gt; pair&lt;iterator, bool&gt; insert(P&amp;&amp; obj);</ins>
4113    iterator       insert(const_iterator hint, const value_type&amp; obj);
4114    <ins>template &lt;class P&gt; iterator       insert(const_iterator hint, P&amp;&amp; obj);</ins>
4115    ...
4116    mapped_type&amp; operator[](const key_type&amp; k);
4117    <ins>mapped_type&amp; operator[](key_type&amp;&amp; k);</ins>
4118    ...
4119};
4120
4121</pre></blockquote>
4122
4123<p>
4124Add to 23.5.1.1 [unord.map.cnstr]:
4125</p>
4126
4127<blockquote>
4128<pre>template &lt;class InputIterator&gt;
4129  unordered_map(InputIterator f, InputIterator l, 
4130                size_type n = <i>implementation-defined</i>, 
4131                const hasher&amp; hf = hasher(), 
4132                const key_equal&amp; eql = key_equal(), 
4133                const allocator_type&amp; a = allocator_type());
4134</pre>
4135
4136<blockquote><p>
4137<ins>
4138<i>Requires:</i> If the iterator's dereference operator returns an
4139lvalue or a const rvalue <tt>pair&lt;key_type, mapped_type&gt;</tt>,
4140then both <tt>key_type</tt> and <tt>mapped_type</tt> shall be
4141<tt>CopyConstructible</tt>.
4142</ins>
4143</p></blockquote>
4144</blockquote>
4145
4146<p>
4147Add to 23.5.1.2 [unord.map.elem]:
4148</p>
4149
4150<blockquote>
4151
4152<pre>mapped_type&amp; operator[](const key_type&amp; k);</pre>
4153
4154<blockquote>
4155<p>...</p>
4156<p><ins>
4157<i>Requires:</i> <tt>key_type</tt> shall be <tt>CopyConstructible</tt>
4158and <tt>mapped_type</tt> shall be <tt>DefaultConstructible</tt>.
4159</ins></p>
4160</blockquote>
4161
4162<pre><ins>mapped_type&amp; operator[](key_type&amp;&amp; k);</ins></pre>
4163
4164<blockquote>
4165<p><ins>
4166<i>Effects:</i> If the <tt>unordered_map</tt> does not already contain an
4167element whose key is equivalent to <tt>k</tt> , inserts the value
4168<tt>std::pair&lt;const key_type, mapped_type&gt;(std::move(k), mapped_type())</tt>.
4169</ins></p>
4170
4171<p><ins>
4172<i>Requires:</i> <tt>mapped_type</tt> shall be <tt>DefaultConstructible</tt>.
4173</ins></p>
4174
4175<p><ins>
4176<i>Returns:</i> A reference to <tt>x.second</tt>, where <tt>x</tt> is the
4177(unique) element whose key is equivalent to <tt>k</tt>.
4178</ins></p>
4179
4180</blockquote>
4181
4182</blockquote>
4183
4184<p>
4185Add new section [unord.map.modifiers]:
4186</p>
4187
4188<blockquote>
4189<pre><ins>pair&lt;iterator, bool&gt; insert(const value_type&amp; x);</ins>
4190<ins>template &lt;class P&gt; pair&lt;iterator, bool&gt; insert(P&amp;&amp; x);</ins>
4191<ins>iterator       insert(const_iterator hint, const value_type&amp; x);</ins>
4192<ins>template &lt;class P&gt; iterator       insert(const_iterator hint, P&amp;&amp; x);</ins>
4193<ins>template &lt;class InputIterator&gt;
4194  void insert(InputIterator first, InputIterator last);</ins>
4195</pre>
4196
4197<blockquote>
4198<p><ins>
4199<i>Requires:</i> Those signatures taking a <tt>const value_type&amp;</tt> parameter
4200requires both the <tt>key_type</tt> and the <tt>mapped_type</tt> to be
4201<tt>CopyConstructible</tt>.
4202 If <tt>P</tt> is instantiated as a reference
4203type, then the argument <tt>x</tt> is copied from. Otherwise <tt>x</tt>
4204is considered to be an rvalue as it is converted to <tt>value_type</tt>
4205and inserted into the <tt>unordered_map</tt>. Specifically, in such
4206cases <tt>CopyConstructible</tt> is not required for <tt>key_type</tt> or
4207<tt>mapped_type</tt> unless the conversion from <tt>P</tt> specifically
4208requires it (e.g. if <tt>P</tt> is a <tt>tuple&lt;const key_type,
4209mapped_type&gt;</tt>, then <tt>key_type</tt> must be
4210<tt>CopyConstructible</tt>).
4211</ins></p>
4212
4213<p><ins>
4214The signature taking <tt>InputIterator</tt>
4215parameters requires <tt>CopyConstructible</tt> of both
4216<tt>key_type</tt> and <tt>mapped_type</tt> if the dereferenced
4217<tt>InputIterator</tt> returns an lvalue or <tt>const</tt> rvalue
4218<tt>value_type</tt>.
4219</ins></p>
4220
4221</blockquote>
4222
4223</blockquote>
4224
4225<p><b><tt>unordered_multimap</tt></b></p>
4226
4227<p>
4228Change 23.5.2 [unord.multimap]:
4229</p>
4230
4231<blockquote><pre>class unordered_multimap
4232{
4233    ...
4234    unordered_multimap(const unordered_multimap&amp;);
4235    <ins>unordered_multimap(unordered_multimap&amp;&amp;);</ins>
4236    ~unordered_multimap();
4237    unordered_multimap&amp; operator=(const unordered_multimap&amp;);
4238    <ins>unordered_multimap&amp; operator=(unordered_multimap&amp;&amp;);</ins>
4239    ...
4240    // modifiers 
4241    iterator insert(const value_type&amp; obj); 
4242    <ins>template &lt;class P&gt; iterator insert(P&amp;&amp; obj);</ins>
4243    iterator       insert(const_iterator hint, const value_type&amp; obj);
4244    <ins>template &lt;class P&gt; iterator       insert(const_iterator hint, P&amp;&amp; obj);</ins>
4245    ...
4246};
4247
4248</pre></blockquote>
4249
4250<p>
4251Add to 23.5.2.1 [unord.multimap.cnstr]:
4252</p>
4253
4254<blockquote>
4255<pre>template &lt;class InputIterator&gt;
4256  unordered_multimap(InputIterator f, InputIterator l, 
4257                size_type n = <i>implementation-defined</i>, 
4258                const hasher&amp; hf = hasher(), 
4259                const key_equal&amp; eql = key_equal(), 
4260                const allocator_type&amp; a = allocator_type());
4261</pre>
4262
4263<blockquote><p>
4264<ins>
4265<i>Requires:</i> If the iterator's dereference operator returns an
4266lvalue or a const rvalue <tt>pair&lt;key_type, mapped_type&gt;</tt>,
4267then both <tt>key_type</tt> and <tt>mapped_type</tt> shall be
4268<tt>CopyConstructible</tt>.
4269</ins>
4270</p></blockquote>
4271</blockquote>
4272
4273<p>
4274Add new section [unord.multimap.modifiers]:
4275</p>
4276
4277<blockquote>
4278<pre><ins>iterator insert(const value_type&amp; x);</ins>
4279<ins>template &lt;class P&gt; iterator       insert(P&amp;&amp; x);</ins>
4280<ins>iterator       insert(const_iterator hint, const value_type&amp; x);</ins>
4281<ins>template &lt;class P&gt; iterator       insert(const_iterator hint, P&amp;&amp; x);</ins>
4282<ins>template &lt;class InputIterator&gt;
4283  void insert(InputIterator first, InputIterator last);</ins>
4284</pre>
4285
4286<blockquote>
4287<p><ins>
4288<i>Requires:</i> Those signatures taking a <tt>const value_type&amp;</tt> parameter
4289requires both the <tt>key_type</tt> and the <tt>mapped_type</tt> to be
4290<tt>CopyConstructible</tt>.
4291If <tt>P</tt> is instantiated as a reference
4292type, then the argument <tt>x</tt> is copied from. Otherwise <tt>x</tt>
4293is considered to be an rvalue as it is converted to <tt>value_type</tt>
4294and inserted into the <tt>unordered_multimap</tt>. Specifically, in such
4295cases <tt>CopyConstructible</tt> is not required for <tt>key_type</tt> or
4296<tt>mapped_type</tt> unless the conversion from <tt>P</tt> specifically
4297requires it (e.g. if <tt>P</tt> is a <tt>tuple&lt;const key_type,
4298mapped_type&gt;</tt>, then <tt>key_type</tt> must be
4299<tt>CopyConstructible</tt>).
4300</ins></p>
4301
4302<p><ins>
4303The signature taking <tt>InputIterator</tt>
4304parameters requires <tt>CopyConstructible</tt> of both
4305<tt>key_type</tt> and <tt>mapped_type</tt> if the dereferenced
4306<tt>InputIterator</tt> returns an lvalue or <tt>const</tt> rvalue
4307<tt>value_type</tt>.
4308</ins></p>
4309</blockquote>
4310
4311</blockquote>
4312
4313<p><b><tt>unordered_set</tt></b></p>
4314
4315<p>
4316Change 23.5.3 [unord.set]:
4317</p>
4318
4319<blockquote><pre>class unordered_set
4320{
4321    ...
4322    unordered_set(const unordered_set&amp;);
4323    <ins>unordered_set(unordered_set&amp;&amp;);</ins>
4324    ~unordered_set();
4325    unordered_set&amp; operator=(const unordered_set&amp;);
4326    <ins>unordered_set&amp; operator=(unordered_set&amp;&amp;);</ins>
4327    ...
4328    // modifiers 
4329    <del>std::</del>pair&lt;iterator, bool&gt; insert(const value_type&amp; obj); 
4330    <ins>pair&lt;iterator, bool&gt; insert(value_type&amp;&amp; obj);</ins>
4331    iterator       insert(const_iterator hint, const value_type&amp; obj);
4332    <ins>iterator       insert(const_iterator hint, value_type&amp;&amp; obj);</ins>
4333    ...
4334};
4335</pre></blockquote>
4336
4337<p>
4338Add to 23.5.3.1 [unord.set.cnstr]:
4339</p>
4340
4341<blockquote>
4342<pre>template &lt;class InputIterator&gt;
4343  unordered_set(InputIterator f, InputIterator l, 
4344                size_type n = <i>implementation-defined</i>, 
4345                const hasher&amp; hf = hasher(), 
4346                const key_equal&amp; eql = key_equal(), 
4347                const allocator_type&amp; a = allocator_type());
4348</pre>
4349
4350<blockquote><p>
4351<ins>
4352<i>Requires:</i> If the iterator's dereference operator returns an
4353lvalue or a const rvalue <tt>value_type</tt>, then the
4354<tt>value_type</tt> shall be <tt>CopyConstructible</tt>.
4355</ins>
4356</p></blockquote>
4357</blockquote>
4358
4359<p>
4360Add new section [unord.set.modifiers]:
4361</p>
4362
4363<blockquote>
4364<pre><ins>pair&lt;iterator, bool&gt; insert(const value_type&amp; x);</ins>
4365<ins>pair&lt;iterator, bool&gt; insert(value_type&amp;&amp; x);</ins>
4366<ins>iterator       insert(const_iterator hint, const value_type&amp; x);</ins>
4367<ins>iterator       insert(const_iterator hint, value_type&amp;&amp; x);</ins>
4368<ins>template &lt;class InputIterator&gt;
4369  void insert(InputIterator first, InputIterator last);</ins>
4370</pre>
4371
4372<blockquote>
4373
4374<p><ins>
4375<i>Requires:</i> Those signatures taking a <tt>const
4376value_type&amp;</tt> parameter requires the <tt>value_type</tt> to
4377be <tt>CopyConstructible</tt>.
4378</ins></p>
4379
4380<p><ins>
4381The signature taking <tt>InputIterator</tt> parameters requires
4382<tt>CopyConstructible</tt> of <tt>value_type</tt> if the dereferenced
4383<tt>InputIterator</tt> returns an lvalue or <tt>const</tt> rvalue
4384<tt>value_type</tt>.
4385</ins></p>
4386
4387</blockquote>
4388
4389</blockquote>
4390
4391<p><b><tt>unordered_multiset</tt></b></p>
4392
4393<p>
4394Change 23.5.4 [unord.multiset]:
4395</p>
4396
4397<blockquote><pre>class unordered_multiset
4398{
4399    ...
4400    unordered_multiset(const unordered_multiset&amp;);
4401    <ins>unordered_multiset(unordered_multiset&amp;&amp;);</ins>
4402    ~unordered_multiset();
4403    unordered_multiset&amp; operator=(const unordered_multiset&amp;);
4404    <ins>unordered_multiset&amp; operator=(unordered_multiset&amp;&amp;);</ins>
4405    ...
4406    // modifiers 
4407    iterator insert(const value_type&amp; obj); 
4408    <ins>iterator insert(value_type&amp;&amp; obj);</ins>
4409    iterator       insert(const_iterator hint, const value_type&amp; obj);
4410    <ins>iterator       insert(const_iterator hint, value_type&amp;&amp; obj);</ins>
4411    ...
4412};
4413
4414</pre></blockquote>
4415
4416<p>
4417Add to 23.5.4.1 [unord.multiset.cnstr]:
4418</p>
4419
4420<blockquote>
4421<pre>template &lt;class InputIterator&gt;
4422  unordered_multiset(InputIterator f, InputIterator l, 
4423                size_type n = <i>implementation-defined</i>, 
4424                const hasher&amp; hf = hasher(), 
4425                const key_equal&amp; eql = key_equal(), 
4426                const allocator_type&amp; a = allocator_type());
4427</pre>
4428
4429<blockquote><p>
4430<ins>
4431<i>Requires:</i> If the iterator's dereference operator returns an
4432lvalue or a const rvalue <tt>value_type</tt>, then the
4433<tt>value_type</tt> shall be <tt>CopyConstructible</tt>.
4434</ins>
4435</p></blockquote>
4436</blockquote>
4437
4438<p>
4439Add new section [unord.multiset.modifiers]:
4440</p>
4441
4442<blockquote>
4443<pre><ins>iterator insert(const value_type&amp; x);</ins>
4444<ins>iterator insert(value_type&amp;&amp; x);</ins>
4445<ins>iterator       insert(const_iterator hint, const value_type&amp; x);</ins>
4446<ins>iterator       insert(const_iterator hint, value_type&amp;&amp; x);</ins>
4447<ins>template &lt;class InputIterator&gt;
4448  void insert(InputIterator first, InputIterator last);</ins>
4449</pre>
4450
4451<blockquote>
4452
4453<p><ins>
4454<i>Requires:</i> Those signatures taking a <tt>const
4455value_type&amp;</tt> parameter requires the <tt>value_type</tt> to
4456be <tt>CopyConstructible</tt>.
4457</ins></p>
4458
4459<p><ins>
4460The signature taking <tt>InputIterator</tt> parameters requires
4461<tt>CopyConstructible</tt> of <tt>value_type</tt> if the dereferenced
4462<tt>InputIterator</tt> returns an lvalue or <tt>const</tt> rvalue
4463<tt>value_type</tt>.
4464</ins></p>
4465
4466</blockquote>
4467
4468</blockquote>
4469
4470
4471
4472<p><i>[
4473Voted to WP in Bellevue.
4474]</i></p>
4475
4476
4477<p><i>[
4478post Bellevue, Pete notes:
4479]</i></p>
4480
4481
4482<blockquote>
4483<p>
4484Please remind people who are reviewing issues to check that the text
4485modifications match the current draft. Issue 676, for example, adds two
4486overloads for unordered_map::insert taking a hint. One takes a
4487const_iterator and returns a const_iterator, and the other takes an
4488iterator and returns an iterator. This was correct at the time the issue
4489was written, but was changed in Toronto so there is only one hint
4490overload, taking a const_iterator and returning an iterator.
4491</p>
4492<p>
4493This issue is not ready. In addition to the relatively minor signature
4494problem I mentioned earlier, it puts requirements in the wrong places.
4495Instead of duplicating requirements throughout the template
4496specifications, it should put them in the front matter that talks about
4497requirements for unordered containers in general. This presentation
4498problem is editorial, but I'm not willing to do the extensive rewrite
4499that it requires. Please put it back into Open status.
4500</p>
4501</blockquote>
4502
4503<p><b>Rationale:</b></p>
4504<p><i>[
4505San Francisco:
4506]</i></p>
4507
4508
4509<blockquote>
4510Solved by
4511<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2776.pdf">N2776</a>.
4512</blockquote>
4513
4514
4515
4516
4517
4518
4519<hr>
4520<h3><a name="704"></a>704. MoveAssignable requirement for container value type overly strict</h3>
4521<p><b>Section:</b> 23.2 [container.requirements] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
4522 <b>Submitter:</b> Howard Hinnant <b>Opened:</b> 2007-05-20  <b>Last modified:</b> 2009-10-20</p>
4523<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#container.requirements">active issues</a> in [container.requirements].</p>
4524<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#container.requirements">issues</a> in [container.requirements].</p>
4525<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
4526<p><b>Discussion:</b></p>
4527<p>
4528The move-related changes inadvertently overwrote the intent of <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#276">276</a>.
4529Issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#276">276</a> removed the requirement of <tt>CopyAssignable</tt> from
4530most of the member functions of node-based containers.  But the move-related changes
4531unnecessarily introduced the <tt>MoveAssignable</tt> requirement for those members which used to
4532require <tt>CopyAssignable</tt>.
4533</p>
4534
4535<p>
4536We also discussed (c++std-lib-18722) the possibility of dropping <tt>MoveAssignable</tt>
4537from some of the sequence requirements.  Additionally the <i>in-place</i> construction
4538work may further reduce requirements.  For purposes of an easy reference, here are the
4539minimum sequence requirements as I currently understand them.  Those items in requirements
4540table in the working draft which do not appear below have been purposefully omitted for
4541brevity as they do not have any requirements of this nature.  Some items which do not
4542have any requirements of this nature are included below just to confirm that they were
4543not omitted by mistake.
4544</p>
4545
4546<table border="1">
4547<caption>Container Requirements</caption>
4548<tbody><tr><td><tt>X u(a)</tt></td><td><tt>value_type</tt> must be <tt>CopyConstructible</tt></td></tr>
4549<tr><td><tt>X u(rv)</tt></td><td><tt>array</tt> and containers with a <tt>propagate_never</tt> allocator require <tt>value_type</tt> to be <tt>MoveConstructible</tt></td></tr>
4550<tr><td><tt>a = u</tt></td><td>Sequences require <tt>value_type</tt> to be <tt>CopyConstructible</tt> and <tt>CopyAssignable</tt>.
4551                               Associative containers require <tt>value_type</tt> to be <tt>CopyConstructible</tt>.</td></tr>
4552<tr><td><tt>a = rv</tt></td><td><tt>array</tt> requires <tt>value_type</tt> to be <tt>MoveAssignable</tt>.
4553                                Sequences and Associative containers with <tt>propagate_never</tt> and <tt>propagate_on_copy_construction</tt> allocators require <tt>value_type</tt> to be <tt>MoveConstructible</tt>.</td></tr>
4554<tr><td><tt>swap(a,u)</tt></td><td><tt>array</tt> and containers with <tt>propagate_never</tt> and
4555                  <tt>propagate_on_copy_construction</tt> allocators require <tt>value_type</tt> to be <tt>Swappable</tt>.</td></tr>
4556</tbody></table>
4557
4558<p>
4559</p>
4560
4561<table border="1">
4562<caption>Sequence Requirements</caption>
4563<tbody><tr><td><tt>X(n)</tt></td><td><tt>value_type</tt> must be <tt>DefaultConstructible</tt></td></tr>
4564<tr><td><tt>X(n, t)</tt></td><td><tt>value_type</tt> must be <tt>CopyConstructible</tt></td></tr>
4565<tr><td><tt>X(i, j)</tt></td><td>If the iterators return an lvalue the <tt>value_type</tt> must be <tt>CopyConstructible</tt>.
4566                                 If the iterators return an rvalue the <tt>value_type</tt> must be <tt>MoveConstructible</tt>.</td></tr>
4567<tr><td><tt>a.insert(p, t)</tt></td><td>The <tt>value_type</tt> must be <tt>CopyConstructible</tt>.
4568                                        The sequences <tt>vector</tt> and <tt>deque</tt> also require the <tt>value_type</tt> to be <tt>CopyAssignable</tt>.</td></tr>
4569<tr><td><tt>a.insert(p, rv)</tt></td><td>The <tt>value_type</tt> must be <tt>MoveConstructible</tt>.
4570                                        The sequences <tt>vector</tt> and <tt>deque</tt> also require the <tt>value_type</tt> to be <tt>MoveAssignable</tt>.</td></tr>
4571<tr><td><tt>a.insert(p, n, t)</tt></td><td>The <tt>value_type</tt> must be <tt>CopyConstructible</tt>.
4572                                        The sequences <tt>vector</tt> and <tt>deque</tt> also require the <tt>value_type</tt> to be <tt>CopyAssignable</tt>.</td></tr>
4573<tr><td><tt>a.insert(p, i, j)</tt></td><td>If the iterators return an lvalue the <tt>value_type</tt> must be <tt>CopyConstructible</tt>.
4574                                        The sequences <tt>vector</tt> and <tt>deque</tt> also require the <tt>value_type</tt> to be <tt>CopyAssignable</tt> when the iterators return an lvalue.
4575                                        If the iterators return an rvalue the <tt>value_type</tt> must be <tt>MoveConstructible</tt>.
4576                                        The sequences <tt>vector</tt> and <tt>deque</tt> also require the <tt>value_type</tt> to be <tt>MoveAssignable</tt> when the iterators return an rvalue.</td></tr>
4577<tr><td><tt>a.erase(p)</tt></td><td>The sequences <tt>vector</tt> and <tt>deque</tt> require the <tt>value_type</tt> to be <tt>MoveAssignable</tt>.</td></tr>
4578<tr><td><tt>a.erase(q1, q2)</tt></td><td>The sequences <tt>vector</tt> and <tt>deque</tt> require the <tt>value_type</tt> to be <tt>MoveAssignable</tt>.</td></tr>
4579<tr><td><tt>a.clear()</tt></td><td></td></tr>
4580<tr><td><tt>a.assign(i, j)</tt></td><td>If the iterators return an lvalue the <tt>value_type</tt> must be <tt>CopyConstructible</tt> and <tt>CopyAssignable</tt>.
4581                                        If the iterators return an rvalue the <tt>value_type</tt> must be <tt>MoveConstructible</tt> and <tt>MoveAssignable</tt>.</td></tr>
4582<tr><td><tt>a.assign(n, t)</tt></td><td>The <tt>value_type</tt> must be <tt>CopyConstructible</tt> and <tt>CopyAssignable</tt>.</td></tr>
4583<tr><td><tt>a.resize(n)</tt></td><td>The <tt>value_type</tt> must be <tt>DefaultConstructible</tt>.
4584                                     The sequence <tt>vector</tt> also requires the <tt>value_type</tt> to be <tt>MoveConstructible</tt>.</td></tr>
4585<tr><td><tt>a.resize(n, t)</tt></td><td>The <tt>value_type</tt> must be <tt>CopyConstructible</tt>.</td></tr>
4586</tbody></table>
4587
4588<p>
4589</p>
4590
4591<table border="1">
4592<caption>Optional Sequence Requirements</caption>
4593<tbody><tr><td><tt>a.front()</tt></td><td></td></tr>
4594<tr><td><tt>a.back()</tt></td><td></td></tr>
4595<tr><td><tt>a.push_front(t)</tt></td><td>The <tt>value_type</tt> must be <tt>CopyConstructible</tt>.</td></tr>
4596<tr><td><tt>a.push_front(rv)</tt></td><td>The <tt>value_type</tt> must be <tt>MoveConstructible</tt>.</td></tr>
4597<tr><td><tt>a.push_back(t)</tt></td><td>The <tt>value_type</tt> must be <tt>CopyConstructible</tt>.</td></tr>
4598<tr><td><tt>a.push_back(rv)</tt></td><td>The <tt>value_type</tt> must be <tt>MoveConstructible</tt>.</td></tr>
4599<tr><td><tt>a.pop_front()</tt></td><td></td></tr>
4600<tr><td><tt>a.pop_back()</tt></td><td></td></tr>
4601<tr><td><tt>a[n]</tt></td><td></td></tr>
4602<tr><td><tt>a.at[n]</tt></td><td></td></tr>
4603</tbody></table>
4604
4605<p>
4606</p>
4607
4608<table border="1">
4609<caption>Associative Container Requirements</caption>
4610<tbody><tr><td><tt>X(i, j)</tt></td><td>If the iterators return an lvalue the <tt>value_type</tt> must be <tt>CopyConstructible</tt>.
4611                                 If the iterators return an rvalue the <tt>value_type</tt> must be <tt>MoveConstructible</tt>.</td></tr>
4612<tr><td><tt>a_uniq.insert(t)</tt></td><td>The <tt>value_type</tt> must be <tt>CopyConstructible</tt>.</td></tr>
4613<tr><td><tt>a_uniq.insert(rv)</tt></td><td>The <tt>key_type</tt> and the <tt>mapped_type</tt> (if it exists) must be <tt>MoveConstructible</tt>.</td></tr>
4614<tr><td><tt>a_eq.insert(t)</tt></td><td>The <tt>value_type</tt> must be <tt>CopyConstructible</tt>.</td></tr>
4615<tr><td><tt>a_eq.insert(rv)</tt></td><td>The <tt>key_type</tt> and the <tt>mapped_type</tt> (if it exists) must be <tt>MoveConstructible</tt>.</td></tr>
4616<tr><td><tt>a.insert(p, t)</tt></td><td>The <tt>value_type</tt> must be <tt>CopyConstructible</tt>.</td></tr>
4617<tr><td><tt>a.insert(p, rv)</tt></td><td>The <tt>key_type</tt> and the <tt>mapped_type</tt> (if it exists) must be <tt>MoveConstructible</tt>.</td></tr>
4618<tr><td><tt>a.insert(i, j)</tt></td><td>If the iterators return an lvalue the <tt>value_type</tt> must be <tt>CopyConstructible</tt>.
4619                                        If the iterators return an rvalue the <tt>key_type</tt> and the <tt>mapped_type</tt> (if it exists) must be <tt>MoveConstructible</tt>..</td></tr>
4620</tbody></table>
4621
4622<p>
4623</p>
4624
4625<table border="1">
4626<caption>Unordered Associative Container Requirements</caption>
4627<tbody><tr><td><tt>X(i, j, n, hf, eq)</tt></td><td>If the iterators return an lvalue the <tt>value_type</tt> must be <tt>CopyConstructible</tt>.
4628                                 If the iterators return an rvalue the <tt>value_type</tt> must be <tt>MoveConstructible</tt>.</td></tr>
4629<tr><td><tt>a_uniq.insert(t)</tt></td><td>The <tt>value_type</tt> must be <tt>CopyConstructible</tt>.</td></tr>
4630<tr><td><tt>a_uniq.insert(rv)</tt></td><td>The <tt>key_type</tt> and the <tt>mapped_type</tt> (if it exists) must be <tt>MoveConstructible</tt>.</td></tr>
4631<tr><td><tt>a_eq.insert(t)</tt></td><td>The <tt>value_type</tt> must be <tt>CopyConstructible</tt>.</td></tr>
4632<tr><td><tt>a_eq.insert(rv)</tt></td><td>The <tt>key_type</tt> and the <tt>mapped_type</tt> (if it exists) must be <tt>MoveConstructible</tt>.</td></tr>
4633<tr><td><tt>a.insert(p, t)</tt></td><td>The <tt>value_type</tt> must be <tt>CopyConstructible</tt>.</td></tr>
4634<tr><td><tt>a.insert(p, rv)</tt></td><td>The <tt>key_type</tt> and the <tt>mapped_type</tt> (if it exists) must be <tt>MoveConstructible</tt>.</td></tr>
4635<tr><td><tt>a.insert(i, j)</tt></td><td>If the iterators return an lvalue the <tt>value_type</tt> must be <tt>CopyConstructible</tt>.
4636                                        If the iterators return an rvalue the <tt>key_type</tt> and the <tt>mapped_type</tt> (if it exists) must be <tt>MoveConstructible</tt>..</td></tr>
4637</tbody></table>
4638
4639<p>
4640</p>
4641
4642<table border="1">
4643<caption>Miscellaneous Requirements</caption>
4644<tbody><tr><td><tt>map[lvalue-key]</tt></td><td>The <tt>key_type</tt> must be <tt>CopyConstructible</tt>.
4645                                         The <tt>mapped_type</tt> must be <tt>DefaultConstructible</tt> and <tt>MoveConstructible</tt>.</td></tr>
4646<tr><td><tt>map[rvalue-key]</tt></td><td>The <tt>key_type</tt> must be <tt>MoveConstructible</tt>.
4647                                         The <tt>mapped_type</tt> must be <tt>DefaultConstructible</tt> and <tt>MoveConstructible</tt>.</td></tr>
4648</tbody></table>
4649
4650<p><i>[
4651Kona (2007): Howard and Alan to update requirements table in issue with emplace signatures.
4652]</i></p>
4653
4654
4655<p><i>[
4656Bellevue: This should be handled as part of the concepts work.
4657]</i></p>
4658
4659
4660<p><i>[
46612009-07-20 Reopened by Howard:
4662]</i></p>
4663
4664
4665<blockquote>
4666<p>
4667This is one of the issues that was "solved by concepts" and is now no longer solved.
4668</p>
4669
4670<p>
4671In a nutshell, concepts adopted the "minimum requirements" philosophy outlined
4672in the discussion of this issue, and enforced it.  My strong suggestion is that
4673we translate the concepts specification into documentation for the containers.
4674</p>
4675
4676<p>
4677What this means for vendors is that they will have to implement container members
4678being careful to only use those characteristics of a type that the concepts specification
4679formally allowed.  Note that I <em>am not</em> talking about <tt>enable_if</tt>'ing
4680everything.  I am simply suggesting that (for example) we tell the vendor he can't call <tt>T's</tt>
4681copy constructor or move constructor within the <tt>emplace</tt> member function, etc.
4682</p>
4683
4684<p>
4685What this means for customers is that they will be able to use types within C++03
4686containers which are sometimes not CopyConstructible, and sometimes not even
4687MoveConstructible, etc.
4688</p>
4689</blockquote>
4690
4691<p><i>[
46922009-10 Santa Cruz:
4693]</i></p>
4694
4695
4696<blockquote>
4697Leave open. Howard to provide wording.
4698</blockquote>
4699
4700
4701
4702<p><b>Proposed resolution:</b></p>
4703
4704
4705
4706<p><b>Rationale:</b></p>
4707<p><i>[
4708post San Francisco:
4709]</i></p>
4710
4711
4712<blockquote>
4713Solved by
4714<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2776.pdf">N2776</a>.
4715</blockquote>
4716
4717
4718
4719
4720
4721
4722<hr>
4723<h3><a name="724"></a>724. <tt>DefaultConstructible</tt> is not defined</h3>
4724<p><b>Section:</b> 20.2.1 [utility.arg.requirements] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
4725 <b>Submitter:</b> Pablo Halpern <b>Opened:</b> 2007-09-12  <b>Last modified:</b> 2009-10-23</p>
4726<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#utility.arg.requirements">active issues</a> in [utility.arg.requirements].</p>
4727<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#utility.arg.requirements">issues</a> in [utility.arg.requirements].</p>
4728<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
4729<p><b>Discussion:</b></p>
4730<p>
4731The <tt>DefaultConstructible</tt> requirement is referenced in
4732several places in the August 2007 working draft
4733<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2369.pdf">N2369</a>,
4734but is not defined anywhere.
4735</p>
4736
4737<p><i>[
4738Bellevue:
4739]</i></p>
4740
4741
4742<blockquote>
4743<p>
4744Walking into the default/value-initialization mess...
4745</p>
4746<p>
4747Why two lines? Because we need both expressions to be valid.
4748</p>
4749<p>
4750AJM not sure what the phrase "default constructed" means. This is
4751unfortunate, as the phrase is already used 24 times in the library!
4752</p>
4753<p>
4754Example: const int would not accept first line, but will accept the second.
4755</p>
4756<p>
4757This is an issue that must be solved by concepts, but we might need to solve it independantly first.
4758</p>
4759<p>
4760It seems that the requirements are the syntax in the proposed first
4761column is valid, but not clear what semantics we need.
4762</p>
4763<p>
4764A table where there is no post-condition seems odd, but appears to sum up our position best.
4765</p>
4766<p>
4767At a minimum an object is declared and is destuctible.
4768</p>
4769<p>
4770Move to open, as no-one happy to produce wording on the fly.
4771</p>
4772</blockquote>
4773
4774<p><i>[
47752009-07-28 Reopened by Alisdair.  No longer solved by concepts.
4776]</i></p>
4777
4778
4779<p><i>[
47802009-08-17 Daniel adds "[defaultconstructible]" to table title.  <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#408">408</a>
4781depends upon this issue.
4782]</i></p>
4783
4784
4785<p><i>[
47862009-08-18 Alisdair adds:
4787]</i></p>
4788
4789
4790<blockquote>
4791<p>
4792Looking at the proposed table in this issue, it really needs two rows:
4793</p>
4794
4795<blockquote>
4796<table border="1">
4797<caption>Table 33: <tt>DefaultConstructible</tt> requirements [defaultconstructible]</caption>
4798<tbody><tr>
4799<th>expression</th><th>post-condition</th>
4800</tr>
4801
4802<tr>
4803<td><tt>T t;</tt></td><td><tt>t</tt> is default-initialized.</td>
4804</tr>
4805
4806<tr>
4807<td><tt>T{}</tt></td><td>Object of type <tt>T</tt> is value-initialized.</td>
4808</tr>
4809</tbody></table>
4810</blockquote>
4811
4812<p>
4813Note I am using the new brace-initialization syntax that is unambiguous
4814in all use cases (no most vexing parse.)
4815</p>
4816</blockquote>
4817
4818<p><i>[
48192009-10-03 Daniel adds:
4820]</i></p>
4821
4822
4823<blockquote>
4824<p>
4825The suggested definition <tt>T{}</tt> describing it as
4826value-initialization is wrong, because it belongs to list-initialization
4827which would - as the current rules are - always prefer a
4828initializer-list constructor over a default-constructor. I don't
4829consider this as an appropriate definition of
4830<tt>DefaultConstructible</tt>. My primary suggestion is to ask core,
4831whether the special case <tt>T{}</tt> (which also easily leads to
4832ambiguity situations for more than one initializer-list in a class)
4833would always prefer a default-constructor - if any - before considering
4834an initializer-list constructor or to provide another syntax form to
4835prefer value-initialization over list-initialization. If that fails I
4836would fall back to suggest to use the expression <tt>T()</tt> instead of
4837<tt>T{}</tt> with all it's disadvantages for the meaning of the
4838expression
4839</p>
4840
4841<blockquote><pre>T t();
4842</pre></blockquote>
4843</blockquote>
4844
4845<p><i>[
48462009-10 Santa Cruz:
4847]</i></p>
4848
4849
4850<blockquote>
4851Leave Open. Core is looking to make Alisdair's proposed
4852resolution correct.
4853</blockquote>
4854
4855
4856
4857<p><b>Proposed resolution:</b></p>
4858<p>
4859In section 20.2.1 [utility.arg.requirements], before table 33, add the
4860following table:
4861</p>
4862
4863<p style="text-align: center;" align="center">Table 33: <tt>DefaultConstructible</tt> requirements [defaultconstructible]</p>
4864
4865<div align="center">
4866
4867<table style="border-collapse: collapse;" border="0" cellpadding="0" cellspacing="0">
4868 <tbody><tr>
4869  <td style="border-style: solid none double solid; border-color: navy -moz-use-text-color navy navy; border-width: 1pt medium 1.5pt 1pt; padding: 0in 5.4pt; width: 85.5pt;" valign="top" width="114">
4870  <p style="margin: 0in 0in 0.0001pt; text-align: center;" align="center">expression</p>
4871  </td>
4872  <td style="border-style: solid solid double none; border-color: navy navy navy -moz-use-text-color; border-width: 1pt 1pt 1.5pt medium; padding: 0in 5.4pt; width: 243pt;" valign="top" width="324">
4873  <p style="margin: 0in 0in 0.0001pt; text-align: center;" align="center">post-condition</p>
4874  </td>
4875 </tr>
4876 <tr>
4877  <td style="border-style: none none solid solid; border-color: -moz-use-text-color -moz-use-text-color navy navy; border-width: medium medium 1pt 1pt; padding: 0in 5.4pt; width: 85.5pt;" valign="top" width="114">
4878  <p style="margin: 0in 0in 0.0001pt;"><tt>T
4879  t;</tt><br>
4880  <tt>T()</tt></p>
4881  </td>
4882  <td style="border-style: none solid solid none; border-color: -moz-use-text-color navy navy -moz-use-text-color; border-width: medium 1pt 1pt medium; padding: 0in 5.4pt; width: 243pt;" valign="top" width="324">
4883  <p style="margin: 0in 0in 0.0001pt;"><tt>T</tt>
4884  is <i>default constructed.</i></p>
4885  </td>
4886 </tr>
4887</tbody></table>
4888
4889</div>
4890
4891
4892
4893<p><b>Rationale:</b></p>
4894<p><i>[
4895San Francisco:
4896]</i></p>
4897
4898<blockquote>
4899We believe concepts will solve this problem
4900(<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2774.pdf">N2774</a>).
4901</blockquote>
4902
4903
4904
4905
4906
4907<hr>
4908<h3><a name="726"></a>726. Missing <tt>regex_replace()</tt> overloads</h3>
4909<p><b>Section:</b> 28.11.4 [re.alg.replace] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
4910 <b>Submitter:</b> Stephan T. Lavavej <b>Opened:</b> 2007-09-22  <b>Last modified:</b> 2009-10-23</p>
4911<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#re.alg.replace">active issues</a> in [re.alg.replace].</p>
4912<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#re.alg.replace">issues</a> in [re.alg.replace].</p>
4913<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
4914<p><b>Discussion:</b></p>
4915<p>
4916Two overloads of <tt>regex_replace()</tt> are currently provided:
4917</p>
4918
4919<blockquote><pre>template &lt;class OutputIterator, class BidirectionalIterator, 
4920    class traits, class charT&gt; 
4921  OutputIterator 
4922  regex_replace(OutputIterator out, 
4923                BidirectionalIterator first, BidirectionalIterator last, 
4924                const basic_regex&lt;charT, traits&gt;&amp; e, 
4925                const basic_string&lt;charT&gt;&amp; fmt, 
4926                regex_constants::match_flag_type flags = 
4927                  regex_constants::match_default);
4928 
4929template &lt;class traits, class charT&gt; 
4930  basic_string&lt;charT&gt; 
4931  regex_replace(const basic_string&lt;charT&gt;&amp; s, 
4932                const basic_regex&lt;charT, traits&gt;&amp; e, 
4933                const basic_string&lt;charT&gt;&amp; fmt, 
4934                regex_constants::match_flag_type flags = 
4935                  regex_constants::match_default);
4936</pre></blockquote>
4937
4938<ol>
4939<li>Overloads taking <tt>const charT *</tt> are provided for <tt>regex_match()</tt> and
4940<tt>regex_search()</tt>, but not <tt>regex_replace()</tt>.  This is inconsistent.</li>
4941<li>
4942<p>The absence of <tt>const charT *</tt> overloads prevents ordinary-looking code from compiling, such as:</p>
4943
4944<blockquote><pre>const string s("kitten");
4945const regex r("en");
4946cout &lt;&lt; regex_replace(s, r, "y") &lt;&lt; endl;
4947</pre></blockquote>
4948
4949<p>
4950The compiler error message will be something like "could not deduce
4951template argument for 'const std::basic_string&lt;_Elem&gt; &amp;' from 'const
4952char[1]'".
4953</p>
4954
4955<p>
4956Users expect that anything taking a <tt>basic_string&lt;charT&gt;</tt> can also take a
4957<tt>const charT *</tt>.  In their own code, when they write a function taking
4958<tt>std::string</tt> (or <tt>std::wstring</tt>), they can pass a <tt>const char *</tt> (or <tt>const
4959wchar_t *</tt>), thanks to <tt>basic_string</tt>'s implicit constructor.  Because the
4960regex algorithms are templated on <tt>charT</tt>, they can't rely on
4961<tt>basic_string</tt>'s implicit constructor (as the compiler error message
4962indicates, template argument deduction fails first).
4963</p>
4964
4965<p>
4966If a user figures out what the compiler error message means, workarounds
4967are available - but they are all verbose.  Explicit template arguments
4968could be given to <tt>regex_replace()</tt>, allowing <tt>basic_string</tt>'s implicit
4969constructor to be invoked - but <tt>charT</tt> is the last template argument, not
4970the first, so this would be extremely verbose.  Therefore, constructing
4971a <tt>basic_string</tt> from each C string is the simplest workaround.
4972</p>
4973</li>
4974
4975<li>
4976There is an efficiency consideration: constructing <tt>basic_string</tt>s can
4977impose performance costs that could be avoided by a library
4978implementation taking C strings and dealing with them directly. 
4979(Currently, for replacement sources, C strings can be converted into
4980iterator pairs at the cost of verbosity, but for format strings, there
4981is no way to avoid constructing a <tt>basic_string</tt>.)
4982</li>
4983</ol>
4984
4985<p><i>[
4986Sophia Antipolis:
4987]</i></p>
4988
4989
4990<blockquote>
4991We note that Boost already has these overloads. However, the proposed
4992wording is provided only for 28.11.4 [re.alg.replace]; wording is needed for the synopsis
4993as well. We also note that this has impact on <tt>match_results::format</tt>,
4994which may require further overloads.
4995</blockquote>
4996
4997<p><i>[
49982009-07 Frankfurt:
4999]</i></p>
5000
5001
5002<blockquote>
5003Daniel to tweak for us.
5004</blockquote>
5005
5006<p><i>[
50072009-07-25 Daniel tweaks both this issue and <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#727">727</a>.
5008]</i></p>
5009
5010
5011<blockquote>
5012<p>
5013This is solved by the proposed resolution of <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#727">727</a>.
5014</p>
5015</blockquote>
5016
5017<p><i>[
50182009-10 Santa Cruz:
5019]</i></p>
5020
5021
5022<blockquote>
5023Leave Open. Though we believe this is solved by the proposed resolution
5024to <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#727">727</a>.
5025</blockquote>
5026
5027
5028
5029<p><b>Proposed resolution:</b></p>
5030
5031<p>
5032Provide additional overloads for <tt>regex_replace()</tt>: one additional
5033overload of the iterator-based form (taking <tt>const charT* fmt</tt>), and three
5034additional overloads of the convenience form (one taking <tt>const charT*
5035str</tt>, another taking <tt>const charT* fmt</tt>, and the third taking both <tt>const
5036charT* str</tt> and <tt>const charT* fmt</tt>).  28.11.4 [re.alg.replace]:
5037</p>
5038
5039<blockquote>
5040<pre>template &lt;class OutputIterator, class BidirectionalIterator, 
5041    class traits, class charT&gt; 
5042  OutputIterator 
5043  regex_replace(OutputIterator out, 
5044                BidirectionalIterator first, BidirectionalIterator last, 
5045                const basic_regex&lt;charT, traits&gt;&amp; e, 
5046                const basic_string&lt;charT&gt;&amp; fmt, 
5047                regex_constants::match_flag_type flags = 
5048                  regex_constants::match_default);
5049
5050<ins>template &lt;class OutputIterator, class BidirectionalIterator, 
5051    class traits, class charT&gt; 
5052  OutputIterator 
5053  regex_replace(OutputIterator out, 
5054                BidirectionalIterator first, BidirectionalIterator last, 
5055                const basic_regex&lt;charT, traits&gt;&amp; e, 
5056                const charT* fmt, 
5057                regex_constants::match_flag_type flags = 
5058                  regex_constants::match_default);</ins>
5059</pre>
5060<p>...</p>
5061<pre>template &lt;class traits, class charT&gt; 
5062  basic_string&lt;charT&gt; 
5063  regex_replace(const basic_string&lt;charT&gt;&amp; s, 
5064                const basic_regex&lt;charT, traits&gt;&amp; e, 
5065                const basic_string&lt;charT&gt;&amp; fmt, 
5066                regex_constants::match_flag_type flags = 
5067                  regex_constants::match_default);
5068
5069<ins>template &lt;class traits, class charT&gt; 
5070  basic_string&lt;charT&gt; 
5071  regex_replace(const basic_string&lt;charT&gt;&amp; s, 
5072                const basic_regex&lt;charT, traits&gt;&amp; e, 
5073                const charT* fmt, 
5074                regex_constants::match_flag_type flags = 
5075                  regex_constants::match_default);</ins>
5076
5077<ins>template &lt;class traits, class charT&gt; 
5078  basic_string&lt;charT&gt; 
5079  regex_replace(const charT* s, 
5080                const basic_regex&lt;charT, traits&gt;&amp; e, 
5081                const basic_string&lt;charT&gt;&amp; fmt, 
5082                regex_constants::match_flag_type flags = 
5083                  regex_constants::match_default);</ins>
5084
5085<ins>template &lt;class traits, class charT&gt; 
5086  basic_string&lt;charT&gt; 
5087  regex_replace(const charT* s, 
5088                const basic_regex&lt;charT, traits&gt;&amp; e, 
5089                const charT* fmt, 
5090                regex_constants::match_flag_type flags = 
5091                  regex_constants::match_default);</ins>
5092</pre>
5093</blockquote>
5094
5095
5096
5097
5098
5099
5100<hr>
5101<h3><a name="727"></a>727. <tt>regex_replace()</tt> doesn't accept <tt>basic_string</tt>s with custom traits and allocators</h3>
5102<p><b>Section:</b> 28.11.4 [re.alg.replace] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Review">Review</a>
5103 <b>Submitter:</b> Stephan T. Lavavej <b>Opened:</b> 2007-09-22  <b>Last modified:</b> 2009-10-23</p>
5104<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#re.alg.replace">active issues</a> in [re.alg.replace].</p>
5105<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#re.alg.replace">issues</a> in [re.alg.replace].</p>
5106<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Review">Review</a> status.</p>
5107<p><b>Discussion:</b></p>
5108<p>
5109<tt>regex_match()</tt> and <tt>regex_search()</tt> take <tt>const basic_string&lt;charT, ST,
5110SA&gt;&amp;</tt>.  <tt>regex_replace()</tt> takes <tt>const basic_string&lt;charT&gt;&amp;</tt>.  This prevents
5111<tt>regex_replace()</tt> from accepting <tt>basic_string</tt>s with custom traits and
5112allocators.
5113</p>
5114
5115<p>
5116Overloads of <tt>regex_replace()</tt> taking <tt>basic_string</tt> should be additionally
5117templated on <tt>class ST, class SA</tt> and take <tt>const basic_string&lt;charT, ST,
5118SA&gt;&amp;</tt>.  Consistency with <tt>regex_match()</tt> and <tt>regex_search()</tt> would place
5119<tt>class ST, class SA</tt> as the first template arguments; compatibility with
5120existing code using TR1 and giving explicit template arguments to
5121<tt>regex_replace()</tt> would place <tt>class ST, class SA</tt> as the last template
5122arguments.
5123</p>
5124
5125<p><i>[
5126Batavia (2009-05):
5127]</i></p>
5128
5129<blockquote>
5130<p>
5131Bill comments, "We need to look at the depth of this change."
5132</p>
5133<p>
5134Pete remarks that we are here dealing with a convenience function
5135that saves a user from calling the iterato-based overload.
5136</p>
5137<p>
5138Move to Open.
5139</p>
5140</blockquote>
5141
5142<p><i>[
51432009-07 Frankfurt:
5144]</i></p>
5145
5146
5147<blockquote>
5148Howard to ask Stephan Lavavej to provide wording.
5149</blockquote>
5150
5151<p><i>[
51522009-07-17 Stephan provided wording.
5153]</i></p>
5154
5155
5156<p><i>[
51572009-07-25 Daniel tweaks both this issue and <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#726">726</a>.
5158]</i></p>
5159
5160
5161<blockquote>
5162<p>
5163One relevant part of the proposed resolution below suggests
5164to add a new overload of the format member function in the
5165<tt>match_results</tt> class template that accepts two character pointers
5166defining the <tt>begin</tt> and <tt>end</tt> of a format range. A more general
5167approach could have proposed a pair of iterators instead, but
5168the used pair of char pointers reflects existing practice. If the
5169committee strongly favors an iterator-based signature, this
5170could be simply changed. I think that the minimum requirement
5171should be a <tt>BidirectionalIterator</tt>, but current implementations
5172take advantage (at least partially) of the <tt>RandomAccessIterator</tt>
5173sub interface of the char pointers.
5174</p>
5175
5176<p><b>Suggested Resolution:</b></p>
5177
5178<p><i>[Moved into the proposed resloution]</i></p>
5179
5180
5181
5182</blockquote>
5183
5184<p><i>[
51852009-07-30 Stephan agrees with Daniel's wording.  Howard places Daniel's wording
5186in the Proposed Resolution.
5187]</i></p>
5188
5189
5190<p><i>[
51912009-10 Santa Cruz:
5192]</i></p>
5193
5194
5195<blockquote>
5196Move to Review. Chair is anxious to move this to Ready in Pittsburgh.
5197</blockquote>
5198
5199
5200
5201<p><b>Proposed resolution:</b></p>
5202
5203<ol>
5204<li>
5205<p>
5206Change 28.4 [re.syn] as indicated:
5207</p>
5208
5209<blockquote><pre>// 28.11.4, function template regex_replace:
5210template &lt;class OutputIterator, class BidirectionalIterator,
5211          class traits, class charT<ins>, class ST, class SA</ins>&gt;
5212  OutputIterator
5213  regex_replace(OutputIterator out,
5214                BidirectionalIterator first, BidirectionalIterator last,
5215                const basic_regex&lt;charT, traits&gt;&amp; e,
5216                const basic_string&lt;charT<ins>, ST, SA</ins>&gt;&amp; fmt,
5217                regex_constants::match_flag_type flags =
5218                  regex_constants::match_default);
5219
5220<ins>
5221template &lt;class OutputIterator, class BidirectionalIterator,
5222          class traits, class charT&gt;
5223  OutputIterator
5224  regex_replace(OutputIterator out,
5225                BidirectionalIterator first, BidirectionalIterator last,
5226                const basic_regex&lt;charT, traits&gt;&amp; e,
5227                const charT* fmt,
5228                regex_constants::match_flag_type flags =
5229                  regex_constants::match_default);
5230</ins>
5231
5232template &lt;class traits, class charT<ins>, class ST, class SA,
5233          class FST, class FSA</ins>&gt;
5234  basic_string&lt;charT<ins>, ST, SA</ins>&gt;
5235  regex_replace(const basic_string&lt;charT<ins>, ST, SA</ins>&gt;&amp; s,
5236                const basic_regex&lt;charT, traits&gt;&amp; e,
5237                const basic_string&lt;charT<ins>, FST, FSA</ins>&gt;&amp; fmt,
5238                regex_constants::match_flag_type flags =
5239                  regex_constants::match_default);
5240
5241<ins>
5242template &lt;class traits, class charT, class ST, class SA&gt;
5243  basic_string&lt;charT, ST, SA&gt;
5244  regex_replace(const basic_string&lt;charT, ST, SA&gt;&amp; s,
5245                const basic_regex&lt;charT, traits&gt;&amp; e,
5246                const charT* fmt,
5247                regex_constants::match_flag_type flags =
5248                  regex_constants::match_default);
5249</ins>
5250
5251<ins>
5252template &lt;class traits, class charT, class ST, class SA&gt;
5253  basic_string&lt;charT&gt;
5254  regex_replace(const charT* s,
5255                const basic_regex&lt;charT, traits&gt;&amp; e,
5256                const basic_string&lt;charT, ST, SA&gt;&amp; fmt,
5257                regex_constants::match_flag_type flags =
5258                  regex_constants::match_default);
5259</ins>
5260
5261<ins>
5262template &lt;class traits, class charT&gt;
5263  basic_string&lt;charT&gt;
5264  regex_replace(const charT* s,
5265                const basic_regex&lt;charT, traits&gt;&amp; e,
5266                const charT* fmt,
5267                regex_constants::match_flag_type flags =
5268                  regex_constants::match_default);
5269</ins>
5270</pre></blockquote>
5271</li>
5272
5273<li>
5274<p>
5275Change 28.10 [re.results]/3, class template <tt>match_results</tt> as
5276indicated:
5277</p>
5278
5279<blockquote><pre><ins>
5280template &lt;class OutputIter&gt;
5281  OutputIter
5282  format(OutputIter out,
5283         const char_type* fmt_first, const char_type* fmt_last,
5284         regex_constants::match_flag_type flags =
5285           regex_constants::format_default) const;
5286</ins>
5287
5288template &lt;class OutputIter<ins>, class ST, class SA</ins>&gt;
5289  OutputIter
5290  format(OutputIter out,
5291         const <del>string_type</del><ins>basic_string&lt;char_type, ST, SA&gt;</ins>&amp; fmt,
5292         regex_constants::match_flag_type flags =
5293           regex_constants::format_default) const;
5294
5295<ins>template &lt;class ST, class SA&gt;</ins>
5296  <del>string_type</del><ins>basic_string&lt;char_type, ST, SA&gt;</ins>
5297  format(const <del>string_type</del><ins>basic_string&lt;char_type, ST, SA&gt;</ins>&amp; fmt,
5298         regex_constants::match_flag_type flags =
5299           regex_constants::format_default) const;
5300
5301<ins>
5302string_type
5303format(const char_type* fmt,
5304       regex_constants::match_flag_type flags =
5305         regex_constants::format_default) const;
5306</ins>
5307</pre></blockquote>
5308</li>
5309
5310<li>
5311<p>
5312Insert at the very beginning of 28.10.4 [re.results.form] the following:
5313</p>
5314
5315<blockquote><pre><ins>
5316template &lt;class OutputIter&gt;
5317  OutputIter
5318  format(OutputIter out,
5319         const char_type* fmt_first, const char_type* fmt_last,
5320         regex_constants::match_flag_type flags =
5321           regex_constants::format_default) const;
5322</ins>
5323</pre>
5324<blockquote>
5325
5326<p><ins>
53271 <i>Requires:</i> The type <tt>OutputIter</tt> shall satisfy the requirements for an
5328Output Iterator (24.2.2 [output.iterators]).
5329</ins></p>
5330
5331<p><ins>
53322 <i>Effects:</i> Copies the character sequence <tt>[fmt_first,fmt_last)</tt> to
5333<tt>OutputIter out</tt>. Replaces each
5334format specifier or escape sequence in the copied range with either
5335the character(s) it represents
5336or the sequence of characters within <tt>*this</tt> to which it refers. The
5337bitmasks specified in <tt>flags</tt>
5338determines what format specifiers and escape sequences are recognized.
5339</ins></p>
5340
5341<p><ins>
53423 <i>Returns:</i> <tt>out</tt>.
5343</ins></p>
5344</blockquote>
5345</blockquote>
5346</li>
5347
5348<li>
5349<p>
5350Change 28.10.4 [re.results.form], before p. 1 until p. 3 (according to
5351previous numbering)
5352as indicated:
5353</p>
5354
5355<blockquote><pre>template &lt;class OutputIter<ins>, class ST, class SA</ins>&gt;
5356  OutputIter
5357  format(OutputIter out,
5358         const <del>string_type</del><ins>basic_string&lt;char_type, ST, SA&gt;</ins>&amp; fmt,
5359         regex_constants::match_flag_type flags =
5360           regex_constants::format_default) const;
5361</pre>
5362
5363<blockquote>
5364<p>
5365<del><i>Requires:</i> The type <tt>OutputIter</tt> shall satisfy the requirements for
5366an Output Iterator (24.2.3).</del>
5367</p>
5368
5369<p>
5370<del><i>Effects:</i> Copies the character sequence <tt>[fmt.begin(),fmt.end())</tt> to
5371<tt>OutputIter out</tt>. Replaces each
5372format specifier or escape sequence in <tt>fmt</tt> with either the
5373character(s) it represents or the sequence of
5374characters within <tt>*this</tt> to which it refers. The bitmasks specified in
5375<tt>flags</tt> determines what format
5376specifiers and escape sequences are recognized.</del>
5377</p>
5378
5379<p>
5380<i>Returns:</i> <tt><del>out</del><ins>format(out, fmt.data(), fmt.data() +
5381fmt.size(), flags)</ins></tt>.
5382</p>
5383</blockquote>
5384</blockquote>
5385</li>
5386
5387<li>
5388<p>
5389Change 28.10.4 [re.results.form], before p. 4 until p. 4 (according to
5390previous numbering) as indicated:
5391</p>
5392
5393<blockquote><pre><ins>template &lt;class ST, class SA&gt;</ins>
5394  <del>string_type</del><ins>basic_string&lt;char_type, ST, SA&gt;</ins>
5395  format(const <del>string_type</del><ins>basic_string&lt;char_type, ST, SA&gt;</ins>&amp; fmt,
5396         regex_constants::match_flag_type flags =
5397           regex_constants::format_default) const;
5398</pre>
5399
5400<blockquote>
5401<p>
5402<i>Effects:</i> <del>Returns a copy of the string <tt>fmt</tt>. Replaces each format
5403specifier or escape sequence
5404in <tt>fmt</tt> with either the character(s) it represents or the sequence of
5405characters within <tt>*this</tt> to which
5406it refers. The bitmasks specified in flags determines what format
5407specifiers and escape sequences are
5408recognized.</del> <ins>Constructs an empty string <tt>result</tt> of type
5409<tt>basic_string&lt;char_type, ST, SA&gt;</tt>,
5410and calls <tt>format(back_inserter(result), fmt, flags)</tt>.</ins>
5411</p>
5412
5413<p>
5414<ins><i>Returns:</i> <tt>result</tt></ins>
5415</p>
5416</blockquote>
5417</blockquote>
5418</li>
5419
5420<li>
5421<p>
5422At the end of 28.10.4 [re.results.form] insert as indicated:
5423</p>
5424
5425<blockquote><pre><ins>
5426string_type
5427  format(const char_type* fmt,
5428         regex_constants::match_flag_type flags =
5429           regex_constants::format_default) const;
5430</ins></pre>
5431
5432<blockquote>
5433<p>
5434<ins><i>Effects:</i> Constructs an empty string <tt>result</tt> of type <tt>string_type</tt>, and calls
5435<tt>format(back_inserter(result), fmt, fmt +
5436char_traits&lt;char_type&gt;::length(fmt), flags)</tt>.</ins>
5437</p>
5438<p>
5439<ins><i>Returns:</i> <tt>result</tt></ins>
5440</p>
5441</blockquote>
5442</blockquote>
5443
5444</li>
5445
5446<li>
5447<p>
5448Change 28.11.4 [re.alg.replace] before p. 1 as indicated:
5449</p>
5450
5451<blockquote><pre>template &lt;class OutputIterator, class BidirectionalIterator,
5452          class traits, class charT<ins>, class ST, class SA</ins>&gt;
5453  OutputIterator
5454  regex_replace(OutputIterator out,
5455                BidirectionalIterator first, BidirectionalIterator last,
5456                const basic_regex&lt;charT, traits&gt;&amp; e,
5457                const basic_string&lt;charT<ins>, ST, SA</ins>&gt;&amp; fmt,
5458                regex_constants::match_flag_type flags =
5459                  regex_constants::match_default);
5460
5461<ins>
5462template &lt;class OutputIterator, class BidirectionalIterator,
5463          class traits, class charT&gt;
5464  OutputIterator
5465  regex_replace(OutputIterator out,
5466                BidirectionalIterator first, BidirectionalIterator last,
5467                const basic_regex&lt;charT, traits&gt;&amp; e,
5468                const charT* fmt,
5469                regex_constants::match_flag_type flags =
5470                  regex_constants::match_default);
5471</ins></pre>
5472
5473<blockquote>
5474<i>Effects:</i> [..]. If any matches are found then, for each such match, if <tt>!(flags &amp;
5475 regex_constants::format_no_copy)</tt> calls <tt>std::copy(m.prefix().first,
5476m.prefix().second,
5477 out)</tt>, and then calls <tt>m.format(out, fmt, flags)</tt> <ins>for the first
5478form of the function
5479 and <tt>m.format(out, fmt, fmt + char_traits&lt;charT&gt;::length(fmt), flags)</tt>
5480for the second
5481 form</ins>. [..].
5482</blockquote>
5483</blockquote>
5484</li>
5485
5486<li>
5487<p>
5488Change 28.11.4 [re.alg.replace] before p. 3 as indicated:
5489</p>
5490
5491<blockquote><pre>template &lt;class traits, class charT<ins>, class ST, class SA,
5492          class FST, class FSA</ins>&gt;
5493  basic_string&lt;charT<ins>, ST, SA</ins>&gt;
5494  regex_replace(const basic_string&lt;charT<ins>, ST, SA</ins>&gt;&amp; s,
5495                const basic_regex&lt;charT, traits&gt;&amp; e,
5496                const basic_string&lt;charT<ins>, FST, FSA</ins>&gt;&amp; fmt,
5497                regex_constants::match_flag_type flags =
5498                  regex_constants::match_default);
5499
5500<ins>
5501template &lt;class traits, class charT, class ST, class SA&gt;
5502  basic_string&lt;charT, ST, SA&gt;
5503  regex_replace(const basic_string&lt;charT, ST, SA&gt;&amp; s,
5504                const basic_regex&lt;charT, traits&gt;&amp; e,
5505                const charT* fmt,
5506                regex_constants::match_flag_type flags =
5507                  regex_constants::match_default);
5508</ins></pre>
5509
5510<blockquote>
5511<i>Effects:</i> Constructs an empty string <tt>result</tt> of type <tt>basic_string&lt;charT<ins>,
5512ST, SA</ins>&gt;</tt>, calls <tt>regex_replace(back_inserter(result), s.begin(), s.end(),
5513e, fmt, flags)</tt>, and then returns <tt>result</tt>.
5514</blockquote>
5515</blockquote>
5516</li>
5517
5518<li>
5519<p>
5520At the end of 28.11.4 [re.alg.replace] add the following new prototype description:
5521</p>
5522
5523<blockquote><pre><ins>
5524template &lt;class traits, class charT, class ST, class SA&gt;
5525  basic_string&lt;charT&gt;
5526  regex_replace(const charT* s,
5527                const basic_regex&lt;charT, traits&gt;&amp; e,
5528                const basic_string&lt;charT, ST, SA&gt;&amp; fmt,
5529                regex_constants::match_flag_type flags =
5530                  regex_constants::match_default);
5531</ins>
5532
5533<ins>
5534template &lt;class traits, class charT&gt;
5535  basic_string&lt;charT&gt;
5536  regex_replace(const charT* s,
5537                const basic_regex&lt;charT, traits&gt;&amp; e,
5538                const charT* fmt,
5539                regex_constants::match_flag_type flags =
5540                  regex_constants::match_default);
5541</ins></pre>
5542
5543<blockquote>
5544<ins>
5545<i>Effects:</i> Constructs an empty string <tt>result</tt> of type <tt>basic_string&lt;charT&gt;</tt>,
5546calls <tt>regex_replace(back_inserter(result), s, s +
5547char_traits&lt;charT&gt;::length(s),
5548e, fmt, flags)</tt>, and then returns <tt>result</tt>.
5549</ins>
5550</blockquote>
5551</blockquote>
5552</li>
5553
5554</ol>
5555
5556
5557
5558
5559
5560
5561
5562<hr>
5563<h3><a name="742"></a>742. Enabling <tt>swap</tt> for proxy iterators</h3>
5564<p><b>Section:</b> 20.2.1 [utility.arg.requirements] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
5565 <b>Submitter:</b> Howard Hinnant <b>Opened:</b> 2007-10-10  <b>Last modified:</b> 2009-11-08</p>
5566<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#utility.arg.requirements">active issues</a> in [utility.arg.requirements].</p>
5567<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#utility.arg.requirements">issues</a> in [utility.arg.requirements].</p>
5568<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
5569<p><b>Discussion:</b></p>
5570<p>
5571This issue was split from <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#672">672</a>. <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#672">672</a> now just
5572deals with changing the requirements of <tt>T</tt> in the <tt>Swappable</tt>
5573requirement from <tt>CopyConstructible</tt> and <tt>CopyAssignable</tt> to
5574<tt>MoveConstructible</tt> and <tt>MoveAssignable</tt>.
5575</p>
5576
5577<p>
5578This issue seeks to widen the <tt>Swappable</tt> requirement to support proxy iterators.  Here
5579is example code:
5580</p>
5581
5582<blockquote><pre>namespace Mine {
5583
5584template &lt;class T&gt;
5585struct proxy {...};
5586
5587template &lt;class T&gt;
5588struct proxied_iterator
5589{
5590   typedef T value_type;
5591   typedef proxy&lt;T&gt; reference;
5592   reference operator*() const;
5593   ...
5594};
5595
5596struct A
5597{
5598   // heavy type, has an optimized swap, maybe isn't even copyable or movable, just swappable
5599   void swap(A&amp;);
5600   ...
5601};
5602
5603void swap(A&amp;, A&amp;);
5604void swap(proxy&lt;A&gt;, A&amp;);
5605void swap(A&amp;, proxy&lt;A&gt;);
5606void swap(proxy&lt;A&gt;, proxy&lt;A&gt;);
5607
5608}  // Mine
5609
5610...
5611
5612Mine::proxied_iterator&lt;Mine::A&gt; i(...)
5613Mine::A a;
5614<b>swap(*i1, a);</b>
5615</pre></blockquote>
5616
5617<p>
5618The key point to note in the above code is that in the call to <tt>swap</tt>, <tt>*i1</tt>
5619and <tt>a</tt> are different types (currently types can only be <tt>Swappable</tt> with the
5620same type).  A secondary point is that to support proxies, one must be able to pass rvalues
5621to <tt>swap</tt>.  But note that I am not stating that the general purpose <tt>std::swap</tt>
5622should accept rvalues!  Only that overloaded <tt>swap</tt>s, as in the example above, be allowed
5623to take rvalues.
5624</p>
5625
5626<p>
5627That is, no standard library code needs to change.  We simply need to have a more flexible
5628definition of <tt>Swappable</tt>.
5629</p>
5630
5631<p><i>[
5632Bellevue:
5633]</i></p>
5634
5635
5636<blockquote>
5637<p>
5638While we believe Concepts work will define a swappable concept, we
5639should still resolve this issue if possible to give guidance to the
5640Concepts work.
5641</p>
5642<p>
5643Would an ambiguous swap function in two namespaces found by ADL break
5644this wording? Suggest that the phrase "valid expression" means such a
5645pair of types would still not be swappable.
5646</p>
5647<p>
5648Motivation is proxy-iterators, but facility is considerably more
5649general. Are we happy going so far?
5650</p>
5651<p>
5652We think this wording is probably correct and probably an improvement on
5653what's there in the WP. On the other hand, what's already there in the
5654WP is awfully complicated. Why do we need the two bullet points? They're
5655too implementation-centric. They don't add anything to the semantics of
5656what swap() means, which is there in the post-condition. What's wrong
5657with saying that types are swappable if you can call swap() and it
5658satisfies the semantics of swapping?
5659</p>
5660</blockquote>
5661
5662<p><i>[
56632009-07-28 Reopened by Alisdair.  No longer solved by concepts.
5664]</i></p>
5665
5666
5667<p><i>[
56682009-10 Santa Cruz:
5669]</i></p>
5670
5671
5672<blockquote>
5673Leave as Open. Dave to provide wording.
5674</blockquote>
5675
5676<p><i>[
56772009-11-08 Howard adds:
5678]</i></p>
5679
5680
5681<blockquote>
5682Updated wording to sync with
5683<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n3000.pdf">N3000</a>.
5684Also this issue is very closely related to <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#594">594</a>.
5685</blockquote>
5686
5687
5688
5689<p><b>Proposed resolution:</b></p>
5690<p>
5691Change 20.2.1 [utility.arg.requirements]:
5692</p>
5693
5694<blockquote>
5695
5696<p>
5697-1- The template definitions in the C++ Standard Library refer to various
5698named requirements whose details are set out in tables 31-38. In these
5699tables, <tt>T</tt> <ins>and <tt>V</tt> are</ins> <del>is a</del> type<ins>s</ins> to be supplied by a C++ program
5700instantiating a template; <tt>a</tt>, <tt>b</tt>, and <tt>c</tt> are
5701values of type <tt>const T</tt>; <tt>s</tt> and <tt>t</tt> are modifiable
5702lvalues of type <tt>T</tt>; <tt>u</tt> is a value of type (possibly
5703<tt>const</tt>) <tt>T</tt>; <del>and</del> <tt>rv</tt> is a non-<tt>const</tt>
5704rvalue of type <tt>T</tt><ins>; <tt>w</tt> is a value of type <tt>T</tt>; and <tt>v</tt> is a value of type <tt>V</tt></ins>.
5705</p>
5706
5707<table border="1">
5708<caption>Table 37: <tt>Swappable</tt> requirements <b>[swappable]</b></caption>
5709<tbody><tr><th>expression</th><th>Return type</th><th>Post-condition</th></tr>
5710<tr><td><tt>swap(<del>s</del><ins>w</ins>,<del>t</del><ins>v</ins>)</tt></td><td><tt>void</tt></td>
5711<td><del><tt>t</tt></del><ins><tt>w</tt></ins> has the value originally
5712held by <del><tt>u</tt></del><ins><tt>v</tt></ins>, and
5713<del><tt>u</tt></del><ins><tt>v</tt></ins> has the value originally held
5714by <del><tt>t</tt></del><ins><tt>w</tt></ins></td></tr>
5715<tr><td colspan="3">
5716<p>
5717The <tt>Swappable</tt> requirement is met by satisfying one or more of the following conditions:
5718</p>
5719<ul>
5720<li>
5721<tt>T</tt> is <tt>Swappable</tt> if <ins><tt>T</tt> and <tt>V</tt> are
5722the same type and </ins> <tt>T</tt> satisfies the
5723<tt>MoveConstructible</tt> requirements (Table 
572433) and the 
5725<tt>MoveAssignable</tt> requirements (Table 
572635);
5727</li>
5728<li>
5729<tt>T</tt> is <tt>Swappable</tt> <ins>with <tt>V</tt></ins> if a namespace scope function named
5730<tt>swap</tt> exists in the same namespace as the definition of
5731<tt>T</tt> <ins>or <tt>V</tt></ins>, such that the expression
5732<tt>swap(<del>s</del><ins>w</ins>,<del>t</del> <ins>v</ins>)</tt> is valid and has the
5733semantics described in this table.
5734</li>
5735<li>
5736<tt>T</tt> is <tt>Swappable</tt> if <tt>T</tt> is an array type whose
5737element type is <tt>Swappable</tt>.
5738</li>
5739</ul>
5740</td></tr>
5741</tbody></table>
5742</blockquote>
5743
5744
5745
5746<p><b>Rationale:</b></p>
5747<p><i>[
5748post San Francisco:
5749]</i></p>
5750
5751
5752<blockquote>
5753Solved by
5754<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2758.pdf">N2758</a>.
5755</blockquote>
5756
5757
5758
5759
5760
5761
5762<hr>
5763<h3><a name="774"></a>774. Member swap undefined for most containers</h3>
5764<p><b>Section:</b> 23 [containers] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
5765 <b>Submitter:</b> Alisdair Meredith <b>Opened:</b> 2008-01-14  <b>Last modified:</b> 2009-10-31</p>
5766<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#containers">active issues</a> in [containers].</p>
5767<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#containers">issues</a> in [containers].</p>
5768<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
5769<p><b>Discussion:</b></p>
5770<p>
5771It appears most containers declare but do not define a member-swap
5772function.
5773</p>
5774
5775<p>
5776This is unfortunate, as all overload the <tt>swap</tt> algorithm to call the
5777member-swap function!
5778(required for <tt>swappable</tt> guarantees [Table 37] and Container Requirements
5779[Table 87])
5780</p>
5781
5782<p>
5783Note in particular that Table 87 gives semantics of <tt>a.swap(b)</tt> as <tt>swap(a,b)</tt>,
5784yet for all containers we define <tt>swap(a,b)</tt> to call <tt>a.swap(b)</tt> - a circular
5785definition.
5786</p>
5787
5788<p>
5789A quick survey of clause 23 shows that the following containers provide a
5790definition for member-swap:
5791</p>
5792
5793<blockquote><pre>array
5794queue
5795stack
5796vector
5797</pre></blockquote>
5798
5799<p>
5800Whereas the following declare it, but do not define the semantics:
5801</p>
5802
5803<blockquote><pre>deque
5804list
5805map
5806multimap
5807multiset
5808priority_queue
5809set
5810unordered_map
5811unordered_multi_map
5812unordered_multi_set
5813unordered_set
5814</pre></blockquote>
5815
5816<p>
5817Suggested resolution:
5818</p>
5819<blockquote>
5820Provide a definition for each of the affected containers...
5821</blockquote>
5822
5823<p><i>[
5824Bellevue:
5825]</i></p>
5826
5827
5828<blockquote>
5829Move to Open and ask Alisdair to provide wording.
5830</blockquote>
5831
5832<p><i>[
58332009-07 Frankfurt:
5834]</i></p>
5835
5836
5837<blockquote>
5838Daniel to provide wording.
5839<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2590.pdf">N2590</a>
5840is no longer applicable.
5841</blockquote>
5842
5843<p><i>[
58442009-07-28 Daniel provided wording.
5845]</i></p>
5846
5847
5848<blockquote>
5849<ol>
5850<li>
5851It assumes that the proposed resolution for <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#883">883</a> is applied,
5852which breaks the circularity of definition between member
5853<tt>swap</tt> and free <tt>swap</tt>.
5854</li>
5855
5856<li>
5857It uses the notation of the pre-concept allocator trait
5858<tt>allocator_propagation_map</tt>, which might be renamed after the
5859next refactoring phase of generalized allocators.
5860</li>
5861
5862<li>
5863It requires that compare objects, key equal functions and
5864hash functions in containers are swapped via unqualified free
5865<tt>swap</tt> according to <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#594">594</a>.
5866</li>
5867</ol>
5868</blockquote>
5869
5870<p><i>[
58712009-09-30 Daniel adds:
5872]</i></p>
5873
5874
5875<blockquote>
5876The outcome of this issue should be considered with the outcome of <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1198">1198</a> both in style and in content (e.g. bullet 9 suggests to
5877define the semantic of <tt>void
5878priority_queue::swap(priority_queue&amp;)</tt> in terms of the member
5879<tt>swap</tt> of the container).
5880</blockquote>
5881
5882<p><i>[
58832009-10 Santa Cruz:
5884]</i></p>
5885
5886
5887<blockquote>
5888Looked at, but took no action on as it overlaps too much with
5889<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2982.pdf">N2982</a>.
5890Waiting for a new draft WP.
5891</blockquote>
5892
5893<p><i>[
58942009-10 Santa Cruz:
5895]</i></p>
5896
5897
5898<blockquote>
5899Leave as open. Pablo to provide wording.
5900</blockquote>
5901
5902<p><i>[
59032009-10-26 Pablo updated wording.  Here is the wording he replaced:
5904]</i></p>
5905
5906
5907<blockquote class="note">
5908<ol>
5909<li>
5910<p>
5911Add a new Throws clause just after X [allocator.propagation.map]/5:
5912</p>
5913
5914<blockquote><pre>static void swap(Alloc&amp; a, Alloc&amp; b);
5915</pre>
5916<blockquote>
5917<p>
5918<i>Effects:</i> [..]
5919</p>
5920
5921<p>
5922<ins><i>Throws:</i> Nothing.</ins>
5923</p>
5924</blockquote>
5925</blockquote>
5926<p><i>[
5927This exception requirement is added, such that it's combination with the
5928general container requirements of
5929<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2723.pdf">N2723</a>
5930[container.requirements.general]/9
5931make it unambiguously clear that the following descriptions of "swaps the
5932allocators" have the following meaning: (a) This swap is done by calling
5933<tt>allocator_propagation_map&lt;allocator_type&gt;::swap</tt> and (b) This allocator
5934swap does never propagate an exception
5935]</i></p>
5936
5937</li>
5938
5939<li>
5940<p>
5941Change 23.2.4.1 [associative.reqmts.except]/3 as indicated:
5942</p>
5943
5944<blockquote>
5945For associative containers, no <tt>swap</tt> function throws an exception unless that
5946exception is thrown by the <del>copy constructor or copy assignment
5947operator</del>
5948<ins><tt>swap</tt></ins> of the container's <tt>Pred</tt> object<ins>s</ins><del> (if any)</del>.
5949</blockquote>
5950</li>
5951
5952<li>
5953<p>
5954Change 23.2.5.1 [unord.req.except]/3 as indicated:
5955</p>
5956
5957<blockquote>
5958For unordered associative containers, no <tt>swap</tt> function throws an
5959exception unless
5960that exception is thrown by the <del>copy constructor or copy
5961assignment operator</del>
5962<ins><tt>swap</tt></ins> of the container's <tt>Hash</tt> or <tt>Pred</tt> object<ins>s,
5963respectively</ins><del> (if any)</del>.
5964</blockquote>
5965</li>
5966
5967<li>
5968<p>
5969Insert a new paragraph just after 23.3 [sequences]/1:
5970</p>
5971
5972<blockquote>
5973<ins>In addition to being available via inclusion of the <tt>&lt;algorithm&gt;</tt> header,
5974the <tt>swap</tt> function templates in 25.3.3 [alg.swap] are also available when the
5975header <tt>&lt;queue&gt;</tt> is included.</ins>
5976</blockquote>
5977
5978<p><i>[
5979There is a new issue in process that will suggest a minimum header for <tt>swap</tt>
5980and <tt>move</tt>. If this one is provided, this text can be removed and the header
5981dependency should be added to <tt>&lt;queue&gt;</tt>
5982]</i></p>
5983
5984
5985</li>
5986
5987<li>
5988<p>
5989Add one further clause at the end of 23.3.1.2 [array.special]:
5990</p>
5991<p><i>[This part is added, because otherwise <tt>array::swap</tt> would otherwise
5992contradict the
5993general contract of 23.2.1 [container.requirements.general] p. 10 b. 5]</i></p>
5994
5995
5996<blockquote>
5997<ins><i>Throws:</i> Nothing, unless one of the element-wise <tt>swap</tt> calls throws
5998an exception.</ins>
5999</blockquote>
6000</li>
6001
6002<li>
6003<ol type="a">
6004<li>
6005<p>
6006In 23.3.2 [deque], class template deque synopsis change as indicated:
6007</p>
6008<blockquote><pre>void swap(deque<del>&lt;T,Alloc&gt;</del>&amp;);
6009</pre></blockquote>
6010</li>
6011
6012<li>
6013<p>
6014At the end of 23.3.2.3 [deque.modifiers] add as indicated:
6015</p>
6016
6017<blockquote><pre><ins>void swap(deque&amp; x);</ins>
6018</pre>
6019<blockquote>
6020<p>
6021<ins><i>Effects:</i> Exchanges the contents and swaps the allocators of <tt>*this</tt>
6022with that of <tt>x</tt>.</ins>
6023</p>
6024<p>
6025<ins><i>Complexity:</i> Constant time.</ins>
6026</p>
6027</blockquote>
6028</blockquote>
6029</li>
6030</ol>
6031</li>
6032
6033<li>
6034<ol type="a">
6035<li>
6036<p>
6037In 23.3.3 [forwardlist], class template <tt>forward_list</tt> synposis change as indicated:
6038</p>
6039
6040<blockquote><pre>void swap(forward_list<del>&lt;T,Allocator&gt;</del>&amp;);
6041</pre></blockquote>
6042</li>
6043
6044<li>
6045<p>
6046At the end of 23.3.3.4 [forwardlist.modifiers] add as indicated:
6047</p>
6048
6049<blockquote><pre><ins>void swap(forward_list&amp; x);</ins>
6050</pre>
6051<blockquote>
6052<p>
6053<ins><i>Effects:</i> Exchanges the contents and swaps the allocators of <tt>*this</tt>
6054with that of <tt>x</tt>.</ins>
6055</p>
6056<p>
6057<ins><i>Complexity:</i> Constant time.</ins>
6058</p>
6059</blockquote>
6060</blockquote>
6061</li>
6062</ol>
6063</li>
6064
6065<li>
6066<ol type="a">
6067<li>
6068<p>
6069In 23.3.4 [list], class template <tt>list</tt> synopsis change as indicated:
6070</p>
6071
6072<blockquote><pre>void swap(list<del>&lt;T,Allocator&gt;</del>&amp;);
6073</pre></blockquote>
6074</li>
6075
6076<li>
6077<p>
6078At the end of 23.3.4.3 [list.modifiers] add as indicated:
6079</p>
6080
6081<blockquote><pre><ins>void swap(list&amp; x);</ins>
6082</pre>
6083
6084<blockquote>
6085<p>
6086<ins><i>Effects:</i> Exchanges the contents and swaps the allocators of <tt>*this</tt>
6087with that of <tt>x</tt>.</ins>
6088</p>
6089
6090<p>
6091<ins><i>Complexity:</i> Constant time.</ins>
6092</p>
6093</blockquote>
6094</blockquote>
6095</li>
6096</ol>
6097</li>
6098
6099<li>
6100<p>
6101At the end of 23.3.5.2.2 [priqueue.members] add a new prototype description:
6102</p>
6103
6104<blockquote><pre><ins>void swap(priority_queue&amp; q);</ins>
6105</pre>
6106<blockquote>
6107<p>
6108<ins><i>Requires:</i> <tt>Compare</tt> shall satisfy the <tt>Swappable</tt> requirements
6109( [swappable]).</ins>
6110</p>
6111
6112<p><i>[
6113This requirement is added to ensure that even a user defined <tt>swap</tt>
6114which is found by
6115ADL for <tt>Compare</tt> satisfies the <tt>Swappable</tt> requirements
6116]</i></p>
6117
6118
6119<p>
6120<ins><i>Effects:</i> <tt>this-&gt;c.swap(q.c); swap(this-&gt;comp, q.comp);</tt></ins>
6121</p>
6122<p>
6123<ins><i>Throws:</i> What and if <tt>c.swap(q.c)</tt> and <tt>swap(comp, q.comp)</tt> throws.</ins>
6124</p>
6125</blockquote>
6126</blockquote>
6127<p><i>[
6128This part is added, because otherwise <tt>priority_queue::swap</tt> would otherwise
6129contradict the general contract of 23.2.1 [container.requirements.general] p. 10 b. 5
6130]</i></p>
6131
6132</li>
6133
6134<li>
6135<ol type="a">
6136<li>
6137<p>
6138In 23.3.6 [vector], class template <tt>vector</tt> synopsis change as indicated:
6139</p>
6140
6141<blockquote><pre>void swap(vector<del>&lt;T,Allocator&gt;</del>&amp;);
6142</pre></blockquote>
6143</li>
6144
6145<li>
6146<p>
6147Change 23.3.6.2 [vector.capacity]/8 as indicated:
6148</p>
6149
6150<blockquote><pre>void swap(vector<del>&lt;T,Allocator&gt;</del>&amp; x);
6151</pre>
6152
6153<blockquote>
6154<i>Effects:</i> Exchanges the contents and <tt>capacity()</tt> <ins>and swaps the
6155allocators</ins>
6156of <tt>*this</tt> with that of <tt>x</tt>.
6157</blockquote>
6158</blockquote>
6159</li>
6160</ol>
6161</li>
6162
6163<li>
6164<p>
6165Insert a new paragraph just before 23.4 [associative]/1:
6166</p>
6167
6168<blockquote>
6169<ins>In addition to being available via inclusion of the <tt>&lt;algorithm&gt;</tt> header,
6170the <tt>swap</tt> function templates in 25.3.3 [alg.swap] are also available when any of the
6171headers <tt>&lt;map&gt;</tt> or <tt>&lt;set&gt;</tt> are included.</ins>
6172</blockquote>
6173</li>
6174
6175<li>
6176<ol type="a">
6177<li>
6178<p>
6179In 23.4.1 [map], class template <tt>map</tt> synopsis change as indicated:
6180</p>
6181
6182<blockquote><pre>void swap(map<del>&lt;Key,T,Compare,Allocator&gt;</del>&amp;);
6183</pre></blockquote>
6184</li>
6185
6186<li>
6187<p>
6188At the end of 23.4.1.3 [map.modifiers] add as indicated:
6189</p>
6190
6191<blockquote><pre><ins>void swap(map&amp; x);</ins>
6192</pre>
6193
6194<blockquote>
6195<p>
6196<ins><i>Requires:</i> Compare shall satisfy the <tt>Swappable</tt> requirements
6197( [swappable]).</ins>
6198</p>
6199
6200<p><i>[
6201This requirement is added to ensure that even a user defined <tt>swap</tt>
6202which is found by ADL for <tt>Compare</tt> satisfies the <tt>Swappable</tt>
6203requirements
6204]</i></p>
6205
6206
6207<p>
6208<ins><i>Effects:</i> Exchanges the contents and swaps the allocators of <tt>*this</tt>
6209with that of <tt>x</tt>, followed by an unqualified <tt>swap</tt> of the comparison objects
6210of <tt>*this</tt> and <tt>x</tt>.</ins>
6211</p>
6212
6213<p>
6214<ins><i>Complexity:</i> Constant time</ins>
6215</p>
6216</blockquote>
6217</blockquote>
6218</li>
6219</ol>
6220</li>
6221
6222<li>
6223<ol type="a">
6224<li>
6225<p>
6226In 23.4.2 [multimap], class template <tt>multimap</tt> synopsis change as indicated:
6227</p>
6228
6229<blockquote><pre>void swap(multimap<del>&lt;Key,T,Compare,Allocator&gt;</del>&amp;);
6230</pre></blockquote>
6231</li>
6232
6233<li>
6234<p>
6235At the end of 23.4.2.2 [multimap.modifiers] add as indicated:
6236</p>
6237
6238<blockquote><pre><ins>void swap(multimap&amp; x);</ins>
6239</pre>
6240
6241<blockquote>
6242<p>
6243<ins><i>Requires:</i> Compare shall satisfy the <tt>Swappable</tt> requirements
6244( [swappable]).</ins>
6245</p>
6246<p>
6247<ins><i>Effects:</i> Exchanges the contents and swaps the allocators of <tt>*this</tt>
6248with that of <tt>x</tt>, followed by an unqualified <tt>swap</tt> of the comparison objects
6249of <tt>*this</tt> and <tt>x</tt>.</ins>
6250</p>
6251<p>
6252<ins><i>Complexity:</i> Constant time</ins>
6253</p>
6254</blockquote>
6255</blockquote>
6256</li>
6257</ol>
6258</li>
6259
6260<li>
6261<ol type="a">
6262<li>
6263<p>
6264In 23.4.3 [set], class template <tt>set</tt> synopsis change as indicated:
6265</p>
6266
6267<blockquote><pre>void swap(set<del>&lt;Key,Compare,Allocator&gt;</del>&amp;);
6268</pre></blockquote>
6269</li>
6270
6271<li>
6272<p>
6273After section 23.4.3.1 [set.cons] add a new section <ins><tt>set</tt> modifiers
6274 [set.modifiers]</ins>
6275and add the following paragraphs:
6276</p>
6277
6278<blockquote><pre><ins>void swap(set&amp; x);</ins>
6279</pre>
6280
6281<blockquote>
6282<p>
6283<ins><i>Requires:</i> Compare shall satisfy the <tt>Swappable</tt> requirements
6284( [swappable]).</ins>
6285</p>
6286
6287<p>
6288<ins><i>Effects:</i> Exchanges the contents and swaps the allocators of <tt>*this</tt>
6289with that of <tt>x</tt>, followed by an unqualified <tt>swap</tt> of the comparison objects
6290of <tt>*this</tt> and <tt>x</tt>.</ins>
6291</p>
6292
6293<p>
6294<ins>Complexity: Constant time</ins>
6295</p>
6296</blockquote>
6297</blockquote>
6298</li>
6299</ol>
6300</li>
6301
6302<li>
6303<ol type="a">
6304<li>
6305<p>
6306In 23.4.4 [multiset], class template <tt>multiset</tt> synosis, change as indicated:
6307</p>
6308
6309<blockquote><pre>void swap(multiset<del>&lt;Key,Compare,Allocator&gt;</del>&amp;);
6310</pre></blockquote>
6311</li>
6312
6313<li>
6314<p>
6315After section 23.4.4.1 [multiset.cons] add a new section <ins><tt>multiset</tt> modifiers
6316 [multiset.modifiers]</ins> and add the following paragraphs:
6317</p>
6318
6319<blockquote><pre><ins>void swap(multiset&amp; x);</ins>
6320</pre>
6321
6322<blockquote>
6323<p>
6324<ins><i>Requires:</i> Compare shall satisfy the <tt>Swappable</tt> requirements
6325( [swappable]).</ins>
6326</p>
6327
6328<p>
6329<ins><i>Effects:</i> Exchanges the contents and swaps the allocators of <tt>*this</tt>
6330with that of <tt>x</tt>, followed by an unqualified <tt>swap</tt> of the comparison objects
6331of <tt>*this</tt> and <tt>x</tt>.</ins>
6332</p>
6333
6334<p>
6335<ins><i>Complexity:</i> Constant time</ins>
6336</p>
6337</blockquote>
6338</blockquote>
6339</li>
6340</ol>
6341</li>
6342
6343<li>
6344<p>
6345Insert a new paragraph just before 23.5 [unord]/1:
6346</p>
6347
6348<blockquote>
6349<ins>In addition to being available via inclusion of the <tt>&lt;algorithm&gt;</tt> header,
6350the <tt>swap</tt> function templates in 25.3.3 [alg.swap] are also available when any of the
6351headers <tt>&lt;unordered_map&gt;</tt> or <tt>&lt;unordered_set&gt;</tt> are included.</ins>
6352</blockquote>
6353
6354</li>
6355
6356<li>
6357<p>
6358After section 23.5.1.2 [unord.map.elem] add a new section <ins>unordered_map
6359modifiers  [unord.map.modifiers]</ins> and add the following paragraphs:
6360</p>
6361
6362<blockquote><pre><ins>void swap(unordered_map&amp; x);</ins>
6363</pre>
6364
6365<blockquote>
6366<p>
6367<ins><i>Requires:</i> <tt>Hash</tt> and <tt>Pred</tt> shall satisfy the <tt>Swappable</tt> requirements
6368( [swappable]).</ins>
6369</p>
6370
6371<p><i>[
6372This requirement is added to ensure that even a user defined <tt>swap</tt>
6373which is found by ADL for <tt>Hash</tt> and <tt>Pred</tt> satisfies the <tt>Swappable</tt>
6374requirements
6375]</i></p>
6376
6377
6378<p>
6379<ins><i>Effects:</i> Exchanges the contents and hash policy and swaps the
6380allocators of <tt>*this</tt>
6381with that of <tt>x</tt>, followed by an unqualified <tt>swap</tt> of the <tt>Pred</tt> objects
6382and an unqualified <tt>swap</tt> of the <tt>Hash</tt> objects of <tt>*this</tt> and <tt>x</tt>.</ins>
6383</p>
6384
6385<p>
6386<ins><i>Complexity:</i> Constant time</ins>
6387</p>
6388</blockquote>
6389</blockquote>
6390</li>
6391
6392<li>
6393<p>
6394After section 23.5.2.1 [unord.multimap.cnstr] add a new section
6395<ins>unordered_multimap
6396modifiers  [unord.multimap.modifiers]</ins> and add the following paragraphs:
6397</p>
6398
6399<blockquote><pre><ins>void swap(unordered_multimap&amp; x);</ins>
6400</pre>
6401
6402<blockquote>
6403<p>
6404<ins><i>Requires:</i> <tt>Hash</tt> and <tt>Pred</tt> shall satisfy the <tt>Swappable</tt> requirements
6405( [swappable]).</ins>
6406</p>
6407
6408<p>
6409<ins><i>Effects:</i> Exchanges the contents and hash policy and swaps the
6410allocators of <tt>*this</tt>
6411with that of <tt>x</tt>, followed by an unqualified <tt>swap</tt> of the <tt>Pred</tt> objects
6412and an unqualified <tt>swap</tt> of the <tt>Hash</tt> objects of <tt>*this</tt> and <tt>x</tt></ins>
6413</p>
6414<p>
6415<ins><i>Complexity:</i> Constant time</ins>
6416</p>
6417</blockquote>
6418</blockquote>
6419</li>
6420
6421<li>
6422<p>
6423After section 23.5.3.1 [unord.set.cnstr] add a new section
6424<ins>unordered_set modifiers
6425 [unord.set.modifiers]</ins> and add the following paragraphs:
6426</p>
6427
6428<blockquote><pre><ins>void swap(unordered_set&amp; x);</ins>
6429</pre>
6430
6431<blockquote>
6432<p>
6433<ins><i>Requires:</i> <tt>Hash</tt> and <tt>Pred</tt> shall satisfy the <tt>Swappable</tt> requirements
6434( [swappable]).</ins>
6435</p>
6436
6437<p>
6438<ins><i>Effects:</i> Exchanges the contents and hash policy and swaps the
6439allocators of <tt>*this</tt>
6440with that of <tt>x</tt>, followed by an unqualified <tt>swap</tt> of the <tt>Pred</tt> objects
6441and an unqualified <tt>swap</tt> of the <tt>Hash</tt> objects of <tt>*this</tt> and <tt>x</tt></ins>
6442</p>
6443
6444<p>
6445<ins><i>Complexity:</i> Constant time</ins>
6446</p>
6447</blockquote>
6448</blockquote>
6449</li>
6450
6451<li>
6452<p>
6453After section 23.5.4.1 [unord.multiset.cnstr] add a new section
6454<ins>unordered_multiset
6455modifiers  [unord.multiset.modifiers]</ins> and add the following paragraphs:
6456</p>
6457
6458<blockquote><pre><ins>void swap(unordered_multiset&amp; x);</ins>
6459</pre>
6460
6461<blockquote>
6462<p>
6463<ins><i>Requires:</i> <tt>Hash</tt> and <tt>Pred</tt> shall satisfy the <tt>Swappable</tt> requirements
6464( [swappable]).</ins>
6465</p>
6466
6467<p>
6468<ins><i>Effects:</i> Exchanges the contents and hash policy and swaps the
6469allocators of <tt>*this</tt>
6470with that of <tt>x</tt>, followed by an unqualified <tt>swap</tt> of the <tt>Pred</tt> objects
6471and an unqualified <tt>swap</tt> of the <tt>Hash</tt> objects of <tt>*this</tt> and <tt>x</tt></ins>
6472</p>
6473<p>
6474<ins><i>Complexity:</i> Constant time</ins>
6475</p>
6476</blockquote>
6477</blockquote>
6478</li>
6479
6480</ol>
6481
6482</blockquote>
6483
6484<p><i>[
64852009-10-30 Pablo and Daniel updated wording.
6486]</i></p>
6487
6488
6489
6490
6491<p><b>Proposed resolution:</b></p>
6492
6493<p><i>[
6494This resolution is based on the September 2009 WP,
6495<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2960.pdf">N2960</a>,
6496except that it
6497assumes that
6498<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2982.pdf">N2982</a>
6499and issues <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#883">883</a> and <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1232">1232</a> have already been applied.  Note in
6500particular that Table 91 in
6501<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2960.pdf">N2960</a>
6502is refered to as Table 90 because
6503<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2982.pdf">N2982</a>
6504removed the old Table 90.  This resolution also addresses issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#431">431</a>.
6505]</i></p>
6506
6507<p>
6508In 23.2.1 [container.requirements.general], replace the a.swap(b) row in table 90,
6509"container requirements" (was table 91 before the application of <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2982.pdf">N2982</a> to the
6510WP):
6511</p>
6512<blockquote>
6513<table border="1">
6514  <tbody><tr>
6515    <td><code>a.swap(b)</code></td>
6516    <td><code>void</code></td>
6517    <td>&nbsp;&nbsp;&nbsp;</td>
6518    <td><code><del>swap(a,b)</del><ins>Exchange the contents of <tt>a</tt> and <tt>b</tt>.</ins></code></td>
6519    <td>(Note A)</td>
6520  </tr>
6521  <tr>
6522    <td><ins><code>swap(a,b)</code></ins></td>
6523    <td><ins><code>void</code></ins></td>
6524    <td><code>&nbsp;&nbsp;&nbsp;</code></td>
6525    <td><ins><code>a.swap(b)</code></ins></td>
6526    <td><ins>(Note A)</ins></td>
6527  </tr>
6528</tbody></table>
6529</blockquote>
6530<p>
6531Modify the notes immediately following Table 90 in
653223.2.1 [container.requirements.general] as follows (The wording below is after the
6533application of <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2982.pdf">N2982</a> to <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2960.pdf">N2960</a>.  The editor might also want to combine Notes
6534A and B into one.):
6535</p>
6536<blockquote><p>
6537Notes: the algorithms<del> swap(),</del> equal() and lexicographical_compare()
6538are defined in Clause 25.  Those entries marked "(Note A)" or "(Note B)"
6539<del>should</del> have <ins>linear complexity for array and</ins> constant
6540complexity <ins>for all other standard containers</ins>.
6541</p></blockquote>
6542<p>
6543In 23.2.1 [container.requirements.general], after paragraph 9, add:
6544</p>
6545<blockquote><p><ins>
6546The expression <code>a.swap(b)</code>, for containers <code>a</code>
6547and <code>b</code> of a standard container type other than <code>array</code>,
6548exchanges the values of <code>a</code> and <code>b</code> without invoking any
6549move, copy, or swap operations on the individual container elements.
6550Any <code>Compare</code>, <code>Pred</code>, or <code>Hash</code> function
6551objects belonging to <code>a</code> and <code>b</code> shall satisfy
6552the <code>Swappable</code> requirements and are exchanged by unqualified calls
6553to non-member <code>swap</code>.  If
6554<code>allocator_traits&lt;allocator_type&gt;::propagate_on_container_swap::value
6555== true</code>, then the allocators of <code>a</code> and <code>b</code> are
6556also exchanged using an unqualified call to non-member <code>swap</code>.
6557Otherwise, the behavior is undefined unless <code>a.get_allocator() ==
6558b.get_allocator()</code>.  Each iterator refering to an element in one
6559container before the swap shall refer to the same element in the other
6560container after the swap.  It is unspecified whether an iterator with
6561value <code>a.end()</code> before the swap will have
6562value <code>b.end()</code> after the swap.  In addition to being available via
6563inclusion of the <code>&lt;utility&gt;</code> header, the <code>swap</code>
6564function template in 25.3.3 [alg.swap] is also available within the definition of
6565every standard container's <code>swap</code> function.
6566</ins></p></blockquote>
6567<p><i>[
6568Note to the editor: Paragraph 2 starts with a sentence fragment,
6569clearly from an editing or source-control error.
6570]</i></p>
6571
6572<p>
6573Modify 23.2.4.1 [associative.reqmts.except] as follows:
6574</p>
6575<blockquote>
6576<p>
6577<b>23.2.4.1 Exception safety guarantees 23.2.4.1 [associative.reqmts.except]</b>
6578</p>
6579<p>
6580For associative containers, no <code>clear()</code> function throws an
6581exception. <code>erase(k)</code> does not throw an exception unless that
6582exception is thrown by the
6583container's <code><del>Pred</del><ins>Compare</ins></code> object (if any).
6584</p>
6585<p>
6586For associative containers, if an exception is thrown by any operation from
6587within an <code>insert()</code> function inserting a single element,
6588the <code>insert()</code> function has no effect.
6589</p>
6590<p>
6591For associative containers, no <code>swap</code> function throws an exception
6592unless that exception is thrown by the <del>copy constructor
6593or copy assignment operator</del><ins>swap</ins> of the
6594container's <code><del>Pred</del><ins>Compare</ins></code> object (if any).
6595</p></blockquote>
6596<p>
6597Modify 23.2.5.1 [unord.req.except], paragraph 3 as follows:
6598</p>
6599<blockquote><p>
6600For unordered associative containers, no <code>swap</code> function throws an
6601exception unless that exception is thrown by the <del>copy constructor or copy
6602assignment operator</del><ins>swap</ins> of the container's <code>Hash</code>
6603or <code>Pred</code> object (if any).
6604</p></blockquote>
6605<p>
6606Modify section 23.3.1.2 [array.special]:
6607</p>
6608<blockquote>
6609<p>
6610<b>array specialized algorithms 23.3.1.2 [array.special]</b>
6611</p>
6612<p>
6613<code>template &lt;class T, size_t N&gt; void swap(array&lt;T,N&gt;&amp; x,array&lt;T,N&gt;&amp; y);</code>
6614</p>
6615<blockquote>
6616<p>
6617<i>Effects:</i> <code><del>swap_ranges(x.begin(), x.end(), y.begin() );</del><ins>x.swap(y);</ins></code>
6618</p>
6619</blockquote>
6620</blockquote>
6621<p>
6622Add a new section after 23.3.1.5 [array.fill] (Note to the editor: array::fill make use
6623of a concept requirement that must be removed or changed to text.):
6624</p>
6625<blockquote>
6626<p>
6627<ins><b>array::swap [array.swap]</b></ins>
6628</p>
6629<p>
6630<ins><code>void swap(array&amp; y);</code></ins>
6631</p>
6632<blockquote>
6633<p><ins>
6634<i>Effects:</i> <code>swap_ranges(this-&gt;begin(), this-&gt;end(), y.begin() );</code>
6635</ins></p>
6636<p><ins>
6637<i>Throws:</i> Nothing unless one of the element-wise swap calls throws an
6638exception.
6639</ins></p>
6640<p><ins>
6641[<i>Note</i>: Unlike other containers' <code>swap</code> functions,
6642<code>array::swap</code> takes linear, not constant, time, may exit via an
6643exception, and does not cause iterators to become associated with the other
6644container. &#8212; <i>end note</i>]
6645</ins></p>
6646</blockquote>
6647</blockquote>
6648
6649<p>
6650Insert a new paragraph just after 23.3.5 [container.adaptors]/1:
6651</p>
6652<blockquote><p><ins>
6653For container adaptors, no <code>swap</code> function throws an exception
6654unless that exception is thrown by the swap of the
6655adaptor's <code>Container</code> or <code>Compare</code> object (if any).
6656</ins></p></blockquote>
6657
6658
6659
6660
6661
6662
6663
6664
6665
6666
6667
6668
6669<hr>
6670<h3><a name="780"></a>780. <tt>std::merge()</tt> specification incorrect/insufficient</h3>
6671<p><b>Section:</b> 25.4.4 [alg.merge] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Review">Review</a>
6672 <b>Submitter:</b> Daniel Kr�gler <b>Opened:</b> 2008-01-25  <b>Last modified:</b> 2009-10-22</p>
6673<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Review">Review</a> status.</p>
6674<p><b>Discussion:</b></p>
6675<p>
6676Though issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#283">283</a> has fixed many open issues, it seems that some are still open:
6677</p>
6678
6679<p>
6680Both 25.3.4 [lib.alg.merge] in 14882:2003 and 25.4.4 [alg.merge] in N2461
6681have no Requires element and the Effects element contains some requirements,
6682which is probably editorial. Worse is that:
6683</p>
6684
6685<ul>
6686<li>
6687no assignment requirements are specified (neither implicit nor explicit).
6688</li>
6689
6690<li>
6691the effects clause just speaks of "merges", which is badly worded
6692near to a circular definition.
6693</li>
6694
6695<li>
6696p. 2 mentions a range <tt>[first, last)</tt>, which is not defined by the
6697function arguments or otherwise.
6698</li>
6699
6700<li>
6701p. 2 says "according to the ordering defined by comp" which is both
6702incomplete (because
6703this excludes the first variant with &lt;) and redundant (because the
6704following subordinate
6705clause mentions comp again)
6706</li>
6707</ul>
6708
6709<p><i>[
6710Post Summit Alisdair adds:
6711]</i></p>
6712
6713
6714<blockquote>
6715<p>
6716Suggest:
6717</p>
6718<blockquote>
6719(where <tt>last</tt> is equal to <tt>next(result, distance(first1, last1) +
6720distance(first2, last2))</tt>, such that resulting range will be sorted in
6721non-decreasing order; that is, for every iterator <tt>i</tt> in <tt>[result,last)</tt> other
6722than <tt>result</tt>, the condition <tt>*i &lt; *prev(i)</tt> or, respectively, <tt>comp(*i,
6723*prev(i))</tt> will be <tt>false</tt>.
6724</blockquote>
6725
6726<p>
6727Note that this might still not be technically accurate in the case of
6728<tt>InputIterators</tt>, depending on other resolutions working their way through the
6729system (<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1011">1011</a>).
6730</p>
6731</blockquote>
6732
6733<p><i>[
6734Post Summit Daniel adds:
6735]</i></p>
6736
6737
6738<blockquote>
6739If we want to use <tt>prev</tt> and <tt>next</tt> here (Note: <tt>merge</tt>
6740is sufficiently satisfied with <tt>InputIterator</tt>) we should instead *add* more to
674125 [algorithms]/6, but I can currently not propose any good wording for this.
6742</blockquote>
6743
6744<p><i>[
6745Batavia (2009-05):
6746]</i></p>
6747
6748<blockquote>
6749<p>
6750Pete points out the existing wording in [algorithms]/4
6751that permits the use of + in algorithm specifications.
6752</p>
6753<p>
6754Alisdair points out that that wording may not apply to input iterators.
6755</p>
6756<p>
6757Move to Review.
6758</p>
6759</blockquote>
6760
6761<p><i>[
67622009-07 Frankfurt:
6763]</i></p>
6764
6765
6766<blockquote>
6767Move to Ready.
6768</blockquote>
6769
6770<p><i>[
67712009-08-23 Daniel reopens:
6772]</i></p>
6773
6774
6775<blockquote>
6776<p>
6777The proposed wording must be rephrased, because the part
6778</p>
6779
6780<blockquote>
6781for every iterator <tt>i</tt> in <tt>[result,last)</tt> other than <tt>result</tt>, the condition
6782<tt>*i &lt; *(i - 1)</tt> or, respectively, <tt>comp(*i, *(i - 1))</tt> will be <tt>false</tt>"
6783</blockquote>
6784
6785<p>
6786isn't meaningful, because the range <tt>[result,last)</tt> is that of a pure
6787<tt>OutputIterator</tt>, which is not <em>readable</em> in general.
6788</p>
6789
6790<p><i>[Howard:  Proposed wording updated by Daniel, status moved from Ready to Review.]</i></p>
6791
6792</blockquote>
6793
6794<p><i>[
67952009-10 Santa Cruz:
6796]</i></p>
6797
6798
6799<blockquote>
6800<p>
6801Matt has some different words to propose.  Those words have been moved into
6802the proposed wording section, and the original proposed wording now appears
6803here:
6804</p>
6805<blockquote>
6806<p>
6807In 25.4.4 [alg.merge] replace p.1+ 2:
6808</p>
6809
6810<blockquote>
6811<p>
6812<i>Effects:</i> <del>Merges</del><ins>Copies all the elements of the</ins>
6813two sorted ranges
6814<tt>[first1,last1)</tt> and <tt>[first2,last2)</tt> into the range <tt>[result,result +
6815(last1 - first1) + (last2 - first2))</tt>
6816<ins>, such that resulting range will be sorted in non-decreasing
6817order; that is for every
6818pair of iterators <tt>i</tt> and <tt>j</tt> of either input ranges, where <tt>*i</tt> was copied
6819to the output range
6820before <tt>*j</tt> was copied to the output range, the condition <tt>*j &lt; *i</tt> or,
6821respectively, <tt>comp(*j, *i)</tt>
6822will be <tt>false</tt>.</ins>
6823</p>
6824
6825<p>
6826<ins><i>Requires:</i></ins>The resulting range shall not overlap with either
6827of the original ranges.
6828<del>The list will be sorted in non-decreasing order according to the
6829ordering defined by
6830<tt>comp</tt>; that is, for every iterator <tt>i</tt> in <tt>[first,last)</tt> other than <tt>first</tt>,
6831the condition <tt>*i &lt; *(i - 1)</tt> or
6832<tt>comp(*i, *(i - 1))</tt> will be <tt>false</tt>.</del>
6833</p>
6834</blockquote>
6835</blockquote>
6836</blockquote>
6837
6838
6839
6840<p><b>Proposed resolution:</b></p>
6841<p><del>
6842<i>Effects:</i> Merges two sorted ranges <tt>[first1,last1)</tt> and
6843<tt>[first2,last2)</tt> into the range <tt>[result, result + (last1 -
6844first1) + (last2 - first2))</tt>.
6845</del></p>
6846<p><ins>
6847<i>Effects:</i> Copies all the elements of the two sorted ranges
6848<tt>[first1,last1)</tt> and <tt>[first2,last2)</tt> into the range
6849<tt>[result, result_last)</tt>, where <tt>result_last</tt> is <tt>result
6850+ (last1 - first1) + (last2 - first2)</tt>, such that the resulting
6851range satisfies <tt>is_sorted(result, result_last)</tt> or
6852<tt>is_sorted(result, result_last, comp)</tt>, respectively.
6853</ins></p>
6854
6855<p>
6856<ins><i>Requires:</i></ins> The resulting range shall not overlap with
6857either of the original ranges.  <del>The list will be sorted in
6858non-decreasing order according to the ordering defined by <tt>comp</tt>;
6859that is, for every iterator <tt>i</tt> in <tt>[first,last)</tt> other
6860than <tt>first</tt>, the condition <tt>*i &lt; *(i - 1)</tt> or
6861<tt>comp(*i, *(i - 1))</tt> will be <tt>false</tt>.</del>
6862</p>
6863
6864
6865
6866
6867
6868
6869<hr>
6870<h3><a name="801"></a>801. <tt>tuple</tt> and <tt>pair</tt> trivial members</h3>
6871<p><b>Section:</b> 20.5 [tuple] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
6872 <b>Submitter:</b> Lawrence Crowl <b>Opened:</b> 2008-02-18  <b>Last modified:</b> 2009-10-23</p>
6873<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#tuple">issues</a> in [tuple].</p>
6874<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
6875<p><b>Discussion:</b></p>
6876<p>
6877Classes with trivial special member functions are inherently more
6878efficient than classes without such functions.  This efficiency is
6879particularly pronounced on modern ABIs that can pass small classes
6880in registers.  Examples include value classes such as complex numbers
6881and floating-point intervals.  Perhaps more important, though, are
6882classes that are simple collections, like <tt>pair</tt> and <tt>tuple</tt>.  When the
6883parameter types of these classes are trivial, the <tt>pair</tt>s and <tt>tuple</tt>s
6884themselves can be trivial, leading to substantial performance wins.
6885</p>
6886<p>
6887The current working draft make specification of trivial functions
6888(where possible) much easer through <tt>default</tt>ed and <tt>delete</tt>d functions.
6889As long as the semantics of defaulted and deleted functions match
6890the intended semantics, specification of defaulted and deleted
6891functions will yield more efficient programs.
6892</p>
6893<p>
6894There are at least two cases where specification of an explicitly
6895defaulted function may be desirable.
6896</p>
6897<p>
6898First, the <tt>std::pair</tt> template has a non-trivial default constructor,
6899which prevents static initialization of the pair even when the
6900types are statically initializable.  Changing the definition to
6901</p>
6902
6903<blockquote><pre>pair() = default;
6904</pre></blockquote>
6905
6906<p>
6907would enable such initialization.  Unfortunately, the change is
6908not semantically neutral in that the current definition effectively
6909forces value initialization whereas the change would not value
6910initialize in some contexts.
6911</p>
6912
6913<p>
6914** Does the committee confirm that forced value initialization
6915was the intent?  If not, does the committee wish to change the
6916behavior of <tt>std::pair</tt> in C++0x?
6917</p>
6918<p>
6919Second, the same default constructor issue applies to <tt>std::tuple</tt>.
6920Furthermore, the <tt>tuple</tt> copy constructor is current non-trivial,
6921which effectively prevents passing it in registers.  To enable
6922passing <tt>tuples</tt> in registers, the copy constructor should be
6923make explicitly <tt>default</tt>ed.  The new declarations are:
6924</p>
6925
6926<blockquote><pre>tuple() = default;
6927tuple(const tuple&amp;) = default;
6928</pre></blockquote>
6929
6930<p>
6931This changes is not implementation neutral.  In particular, it
6932prevents implementations based on pointers to the parameter
6933types.  It does however, permit implementations using the
6934parameter types as bases.
6935</p>
6936<p>
6937** How does the committee wish to trade implementation
6938efficiency versus implementation flexibility?
6939</p>
6940
6941<p><i>[
6942Bellevue:
6943]</i></p>
6944
6945
6946<blockquote>
6947<p>
6948General agreement; the first half of the issue is NAD.
6949</p>
6950<p>
6951Before voting on the second half, it was agreed that a "Strongly Favor"
6952vote meant support for trivial tuples (assuming usual requirements met),
6953even at the expense of other desired qualities. A "Weakly Favor" vote
6954meant support only if not at the expense of other desired qualities.
6955</p>
6956<p>
6957Concensus: Go forward, but not at expense of other desired qualities.
6958</p>
6959<p>
6960It was agreed to Alisdair should fold this work in with his other
6961pair/tuple action items, above, and that issue 801 should be "open", but
6962tabled until Alisdair's proposals are disposed of.
6963</p>
6964</blockquote>
6965
6966<p><i>[
69672009-05-27 Daniel adds:
6968]</i></p>
6969
6970
6971<blockquote>
6972This is partly solved by <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1117">1117</a>.
6973</blockquote>
6974
6975<p><i>[
69762009-07 Frankfurt:
6977]</i></p>
6978
6979
6980<blockquote>
6981Wait for dust to settle from fixing exception safety problem
6982with rvalue refs.
6983</blockquote>
6984
6985<p><i>[
69862009-07-20 Alisdair adds:
6987]</i></p>
6988
6989
6990<blockquote>
6991<p>
6992Basically, this issue is what should we do with the default constructor
6993for pairs and tuples of trivial types.  The motivation of the issue was
6994to force static initialization rather than dynamic initialization, and
6995was rejected in the case of pair as it would change the meaning of
6996existing programs.  The advice was "do the best we can" for tuple
6997without changing existing meaning.
6998</p>
6999
7000<p>
7001Frankfurt seems to simply wait and see the resolution on no-throw move
7002constructors, which (I believe) is only tangentially related to this
7003issue, but as good as any to defer until Santa Cruz.
7004</p>
7005
7006<p>
7007Looking again now, I think constant (static) initialization for pair can
7008be salvaged by making the default construct constexpr.  I have a
7009clarification from Core that this is intended to work, even if the
7010constructor is not trivial/constexpr, so long as no temporaries are
7011implied in the process (even if elided).
7012</p>
7013</blockquote>
7014
7015<p><i>[
70162009-10 Santa Cruz:
7017]</i></p>
7018
7019
7020<blockquote>
7021Leave as open. Alisdair to provide wording.
7022</blockquote>
7023
7024
7025
7026<p><b>Proposed resolution:</b></p>
7027<p>
7028</p>
7029
7030
7031
7032
7033
7034<hr>
7035<h3><a name="811"></a>811. <tt>pair</tt> of pointers no longer works with literal 0</h3>
7036<p><b>Section:</b> 20.3.4 [pairs] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
7037 <b>Submitter:</b> Doug Gregor <b>Opened:</b> 2008-03-14  <b>Last modified:</b> 2009-10-23</p>
7038<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#pairs">active issues</a> in [pairs].</p>
7039<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#pairs">issues</a> in [pairs].</p>
7040<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
7041<p><b>Discussion:</b></p>
7042<blockquote><pre>#include &lt;utility&gt;
7043
7044int main()
7045{
7046   std::pair&lt;char *, char *&gt; p (0,0);
7047}
7048</pre></blockquote>
7049
7050<p>
7051I just got a bug report about that, because it's valid C++03, but not
7052C++0x. The important realization, for me, is that the emplace
7053proposal---which made <tt>push_back</tt> variadic, causing the <tt>push_back(0)</tt>
7054issue---didn't cause this break in backward compatibility. The break
7055actually happened when we added this pair constructor as part of adding
7056rvalue references into the language, long before variadic templates or
7057emplace came along:
7058</p>
7059
7060<blockquote><pre>template&lt;class U, class V&gt; pair(U&amp;&amp; x, V&amp;&amp; y);
7061</pre></blockquote>
7062
7063<p>
7064Now, concepts will address this issue by constraining that <tt>pair</tt>
7065constructor to only <tt>U</tt>'s and <tt>V</tt>'s that can properly construct "first" and
7066"second", e.g. (from
7067<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2322.pdf">N2322</a>):
7068</p>
7069
7070<blockquote><pre>template&lt;class U , class V &gt;
7071requires Constructible&lt;T1, U&amp;&amp;&gt; &amp;&amp; Constructible&lt;T2, V&amp;&amp;&gt;
7072pair(U&amp;&amp; x , V&amp;&amp; y );
7073</pre></blockquote>
7074
7075<p><i>[
7076San Francisco:
7077]</i></p>
7078
7079
7080<blockquote>
7081<p>
7082Suggested to resolve using pass-by-value for that case.
7083</p>
7084<p>
7085Side question: Should pair interoperate with tuples? Can construct a
7086tuple of a pair, but not a pair from a two-element tuple.
7087</p>
7088<p>
7089Related to <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#885">885</a>.
7090</p>
7091</blockquote>
7092
7093<p><i>[
70942009-07-28 Reopened by Alisdair.  No longer solved by concepts.
7095]</i></p>
7096
7097
7098<p><i>[
70992009-10 Santa Cruz:
7100]</i></p>
7101
7102
7103<blockquote>
7104Leave as open. Howard to provide wording.
7105</blockquote>
7106
7107
7108
7109<p><b>Proposed resolution:</b></p>
7110<p>
7111</p>
7112
7113
7114<p><b>Rationale:</b></p>
7115<p><i>[
7116San Francisco:
7117]</i></p>
7118
7119
7120<blockquote>
7121Solved by
7122<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2770.pdf">N2770</a>.
7123</blockquote>
7124
7125
7126
7127
7128
7129
7130
7131<hr>
7132<h3><a name="815"></a>815. <tt>std::function</tt> and <tt>reference_closure</tt> do not use perfect forwarding</h3>
7133<p><b>Section:</b> 20.7.15.2.4 [func.wrap.func.inv] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
7134 <b>Submitter:</b> Alisdair Meredith <b>Opened:</b> 2008-03-16  <b>Last modified:</b> 2009-10-23</p>
7135<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
7136<p><b>Discussion:</b></p>
7137<p>
7138<tt>std::function</tt> and <tt>reference_closure</tt> should use "perfect forwarding" as
7139described in the rvalue core proposal.
7140</p>
7141
7142<p><i>[
7143Sophia Antipolis:
7144]</i></p>
7145
7146
7147<blockquote>
7148According to Doug Gregor, as far as <tt>std::function</tt> is concerned, perfect
7149forwarding can not be obtained because of type erasure. Not everyone
7150agreed with this diagnosis of forwarding.
7151</blockquote>
7152
7153<p><i>[
71542009-05-01 Howard adds:
7155]</i></p>
7156
7157
7158<blockquote>
7159<p>
7160Sebastian Gesemann brought to my attention that the <tt>CopyConstructible</tt>
7161requirement on <tt>function</tt>'s <tt>ArgTypes...</tt> is an unnecessary
7162restriction.
7163</p>
7164
7165<blockquote><pre>template&lt;Returnable R, <b>CopyConstructible</b>... ArgTypes&gt;
7166class function&lt;R(ArgTypes...)&gt;
7167...
7168</pre></blockquote>
7169
7170<p>
7171On further investigation, this complaint seemed to be the same
7172issue as this one.  I believe the reason <tt>CopyConstructible</tt> was put
7173on <tt>ArgTypes</tt> in the first place was because of the nature of the
7174<i>invoke</i> member:
7175</p>
7176
7177<blockquote><pre>template&lt;class R, class ...ArgTypes&gt;
7178R
7179function&lt;R(ArgTypes...)&gt;::operator()(ArgTypes... arg) const
7180{
7181    if (f_ == 0)
7182        throw bad_function_call();
7183    return (*f_)(arg...);
7184}
7185</pre></blockquote>
7186
7187<p>
7188However now with rvalue-refs, "by value" no longer implies <tt>CopyConstructible</tt>
7189(as Sebastian correctly points out).  If rvalue arguments are supplied, <tt>MoveConstructible</tt>
7190is sufficient.  Furthermore, the constraint need not be applied in <tt>function</tt>
7191if I understand correctly.  Rather the client must apply the proper constraints
7192at the call site.  Therefore, at the very least, I recommend that <tt>CopyConstructible</tt>
7193be removed from the template class <tt>function</tt>.
7194</p>
7195
7196<p>
7197Furthermore we need to mandate that the <i>invoker</i> is coded as:
7198</p>
7199
7200<blockquote><pre>template&lt;class R, class ...ArgTypes&gt;
7201R
7202function&lt;R(ArgTypes...)&gt;::operator()(ArgTypes... arg) const
7203{
7204    if (f_ == 0)
7205        throw bad_function_call();
7206    return (*f_)(<b>std::forward&lt;ArgTypes&gt;(</b>arg<b>)</b>...);
7207}
7208</pre></blockquote>
7209
7210<p>
7211Note that <tt>ArgTypes&amp;&amp;</tt> (the "perfect forwarding signature") is not 
7212appropriate here as this is not a deduced context for <tt>ArgTypes</tt>.  Instead
7213the client's arguments must implicitly convert to the non-deduced <tt>ArgType</tt>
7214type.  Catching these arguments by value makes sense to enable decay.
7215</p>
7216
7217<p>
7218Next <tt>forward</tt> is used to move the <tt>ArgTypes</tt> as efficiently as
7219possible, and also with minimum requirements (not <tt>CopyConstructible</tt>)
7220to the type-erased functor.  For object types, this will be a <tt>move</tt>.  For
7221reference type <tt>ArgTypes</tt>, this will be a copy.  The end result <em>must</em> be
7222that the following is a valid program:
7223</p>
7224
7225<blockquote><pre>#include &lt;functional&gt;
7226#include &lt;memory&gt;
7227#include &lt;cassert&gt;
7228
7229std::unique_ptr&lt;int&gt;
7230f(std::unique_ptr&lt;int&gt; p, int&amp; i)
7231{
7232    ++i;
7233    return std::move(p);
7234}
7235
7236int main()
7237{
7238    int i = 2;
7239    std::function&lt;std::unique_ptr&lt;int&gt;(std::unique_ptr&lt;int&gt;,
7240                                       int&amp;&gt; g(f);
7241    std::unique_ptr&lt;int&gt; p = g(std::unique_ptr&lt;int&gt;(new int(1)), i);
7242    assert(*p == 1);
7243    assert(i == 3);
7244}
7245</pre></blockquote>
7246
7247<p><i>[
7248Tested in pre-concepts rvalue-ref-enabled compiler.
7249]</i></p>
7250
7251
7252<p>
7253In the example above, the first <tt>ArgType</tt> is <tt>unique_ptr&lt;int&gt;</tt>
7254and the second <tt>ArgType</tt> is <tt>int&amp;</tt>.  Both <em>must</em> work!
7255</p>
7256
7257</blockquote>
7258
7259<p><i>[
72602009-05-27 Daniel adds:
7261]</i></p>
7262
7263
7264<blockquote>
7265<p>
7266in the 2009-05-01 comment of above mentioned issue Howard
7267</p>
7268
7269<ol type="a">
7270<li>
7271Recommends to replace the <tt>CopyConstructible</tt> requirement by a
7272<tt>MoveConstructible</tt> requirement
7273</li>
7274<li>
7275Says: "Furthermore, the constraint need not be applied in <tt>function</tt> if I
7276understand correctly. Rather the client must apply the proper constraints
7277at the call site"
7278</li>
7279</ol>
7280<p>
7281I'm fine with (a), but I think comment (b) is incorrect, at least in the
7282sense I read these sentences. Let's look at Howard's example code:
7283</p>
7284
7285<blockquote><pre>function&lt;R(ArgTypes...)&gt;::operator()(ArgTypes... arg) const
7286{
7287   if (f_ == 0)
7288       throw bad_function_call();
7289   return (*f_)(std::forward&lt;ArgTypes&gt;(arg)...);
7290}
7291</pre></blockquote>
7292
7293<p>
7294In the constrained scope of this <tt>operator()</tt> overload the expression
7295"<tt>(*f_)(std::forward&lt;ArgTypes&gt;(arg)...)</tt>" must be valid. How can it
7296do so, if <tt>ArgTypes</tt> aren't at least <tt>MoveConstructible</tt>?
7297</p>
7298</blockquote>
7299
7300<p><i>[
73012009-07 Frankfurt:
7302]</i></p>
7303
7304
7305<blockquote>
7306Leave this open and wait until concepts are removed from the Working
7307Draft so that we know how to write the proposed resolution in terms of
7308diffs to otherwise stable text.
7309</blockquote>
7310
7311<p><i>[
73122009-10 Santa Cruz:
7313]</i></p>
7314
7315
7316<blockquote>
7317Leave as open. Howard to provide wording. Howard welcomes any help.
7318</blockquote>
7319
7320
7321
7322<p><b>Proposed resolution:</b></p>
7323<p>
7324</p>
7325
7326
7327
7328
7329
7330<hr>
7331<h3><a name="816"></a>816. Should <tt>bind()</tt>'s returned functor have a nofail copy ctor when <tt>bind()</tt> is nofail?</h3>
7332<p><b>Section:</b> 20.7.11.1.3 [func.bind.bind] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
7333 <b>Submitter:</b> Stephan T. Lavavej <b>Opened:</b> 2008-02-08  <b>Last modified:</b> 2009-11-07</p>
7334<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#func.bind.bind">active issues</a> in [func.bind.bind].</p>
7335<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#func.bind.bind">issues</a> in [func.bind.bind].</p>
7336<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
7337<p><b>Discussion:</b></p>
7338<p>
7339Library Issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#527">527</a> notes that <tt>bind(f, t1, ..., tN)</tt>
7340should be nofail when <tt>f, t1, ..., tN</tt> have nofail copy ctors.
7341</p>
7342<p>
7343However, no guarantees are provided for the copy ctor of the functor
7344returned by <tt>bind()</tt>.  (It's guaranteed to have a copy ctor, which can
7345throw implementation-defined exceptions: <tt>bind()</tt> returns a forwarding
7346call wrapper, TR1 3.6.3/2.  A forwarding call wrapper is a call wrapper,
7347TR1 3.3/4.  Every call wrapper shall be CopyConstructible, TR1 3.3/4.
7348Everything without an exception-specification may throw
7349implementation-defined exceptions unless otherwise specified, C++03
735017.4.4.8/3.)
7351</p>
7352<p>
7353Should the nofail guarantee requested by Library Issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#527">527</a> be extended
7354to cover both calling <tt>bind()</tt> and copying the returned functor?
7355</p>
7356
7357<p><i>[
7358Howard adds:
7359]</i></p>
7360
7361
7362<blockquote>
7363<tt>tuple</tt> construction should probably have a similar guarantee.
7364</blockquote>
7365
7366<p><i>[
7367San Francisco:
7368]</i></p>
7369
7370
7371<blockquote>
7372Howard to provide wording.
7373</blockquote>
7374
7375<p><i>[
7376Post Summit, Anthony provided wording.
7377]</i></p>
7378
7379
7380<p><i>[
7381Batavia (2009-05):
7382]</i></p>
7383
7384<blockquote>
7385Part of all of this issue appears to be rendered moot
7386by the proposed resolution to issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#817">817</a> (q.v.).
7387We recommend the issues be considered simultaneously
7388(or possibly even merged)
7389to ensure there is no overlap.
7390Move to Open, and likewise for issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#817">817</a>.
7391</blockquote>
7392
7393<p><i>[
73942009-07 Frankfurt:
7395]</i></p>
7396
7397
7398<blockquote>
7399Related to <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#817">817</a> (see below). Leave Open.
7400</blockquote>
7401
7402<p><i>[
74032009-10 Santa Cruz:
7404]</i></p>
7405
7406
7407<blockquote>
7408Move to Ready. Decoupling from issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#817">817</a>.
7409</blockquote>
7410
7411
7412
7413<p><b>Proposed resolution:</b></p>
7414<p>
7415Add a new sentence to the end of paragraphs 2 and 4 of 20.7.11.1.3 [func.bind.bind]:
7416</p>
7417
7418<blockquote>
7419<p>
7420-2- <i>Returns:</i> A forwarding call wrapper <tt>g</tt> with a weak result type (20.6.2). The effect of <tt>g(u1, u2,
7421..., uM)</tt> shall be <tt><i>INVOKE</i>(f, v1, v2, ..., vN, Callable&lt;F cv,V1, V2, ..., VN&gt;::result_type)</tt>, where <i>cv</i>
7422represents the <i>cv</i>-qualifiers of <tt>g</tt> and the values and types of the bound arguments
7423<tt>v1, v2, ..., vN</tt> are determined as specified below.
7424<ins>The copy constructor and move constructor of the forwarding call wrapper shall throw an
7425exception if and only if the corresponding constructor of <tt>F</tt> or any of the types
7426in <tt>BoundArgs...</tt> throw an exception.</ins>
7427</p>
7428<p>...</p>
7429<p>
7430-5- <i>Returns:</i> A forwarding call wrapper <tt>g</tt> with a nested type <tt>result_type</tt> defined as a synonym
7431for <tt>R</tt>. The effect of <tt>g(u1, u2, ..., uM)</tt> shall be <tt><i>INVOKE</i>(f, v1, v2, ..., vN, R)</tt>, where the
7432values and types of the bound arguments <tt>v1, v2, ..., vN</tt> are determined as specified below.
7433<ins>The copy constructor and move constructor of the forwarding call wrapper shall throw an
7434exception if and only if the corresponding constructor of <tt>F</tt> or any of the types
7435in <tt>BoundArgs...</tt> throw an exception.</ins>
7436</p>
7437
7438</blockquote>
7439
7440
7441
7442
7443
7444<hr>
7445<h3><a name="817"></a>817. <tt>bind</tt> needs to be moved</h3>
7446<p><b>Section:</b> 20.7.11.1.3 [func.bind.bind] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
7447 <b>Submitter:</b> Howard Hinnant <b>Opened:</b> 2008-03-17  <b>Last modified:</b> 2009-11-08</p>
7448<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#func.bind.bind">active issues</a> in [func.bind.bind].</p>
7449<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#func.bind.bind">issues</a> in [func.bind.bind].</p>
7450<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
7451<p><b>Discussion:</b></p>
7452<p><b>Addresses US 72, JP 38 and DE 21</b></p>
7453
7454<p>
7455The functor returned by <tt>bind()</tt> should have a move constructor that
7456requires only move construction of its contained functor and bound arguments.
7457That way move-only functors can be passed to objects such as <tt>thread</tt>.
7458</p>
7459<p>
7460This issue is related to issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#816">816</a>.
7461</p>
7462
7463<p>
7464US 72:
7465</p>
7466
7467<blockquote>
7468<tt>bind</tt> should support move-only functors and bound arguments.
7469</blockquote>
7470
7471<p>
7472JP 38:
7473</p>
7474
7475<blockquote>
7476<p>
7477add the move requirement for bind's return type.
7478</p>
7479<p>
7480For example, assume following <tt>th1</tt> and <tt>th2</tt>,
7481</p>
7482
7483<blockquote><pre>void f(vector&lt;int&gt; v) { }
7484
7485vector&lt;int&gt; v{ ... };
7486thread th1([v]{ f(v); });
7487thread th2(bind(f, v));
7488</pre></blockquote>
7489
7490<p>
7491When function object are set to thread, <tt>v</tt> is moved to <tt>th1</tt>'s lambda
7492expression in a Move Constructor of lambda expression because <tt>th1</tt>'s lambda
7493expression has a Move Constructor. But <tt>bind</tt> of <tt>th2</tt>'s
7494return type doesn't have the requirement of Move, so it may not
7495moved but copied.
7496</p>
7497<p>
7498Add the requirement of move to get rid of this useless copy.
7499</p>
7500<p>
7501And also, add the <tt>MoveConstructible</tt> as well as <tt>CopyConstructible</tt>.
7502</p>
7503</blockquote>
7504
7505<p>
7506DE 21
7507</p>
7508
7509<blockquote>
7510The specification for bind claims twice that "the values and types for
7511the bound arguments v1, v2, ..., vN are determined as specified below".
7512No such specification appears to exist.
7513</blockquote>
7514
7515<p><i>[
7516San Francisco:
7517]</i></p>
7518
7519
7520<blockquote>
7521Howard to provide wording.
7522</blockquote>
7523
7524<p><i>[
7525Post Summit Alisdair and Howard provided wording.
7526]</i></p>
7527
7528
7529<blockquote>
7530<p>
7531Several issues are being combined in this resolution.  They are all touching the
7532same words so this is an attempt to keep one issue from stepping on another, and
7533a place to see the complete solution in one place.
7534</p>
7535
7536<ol>
7537<li>
7538<tt>bind</tt> needs to be "moved".
7539</li>
7540<li>
754120.7.11.1.3 [func.bind.bind]/p3, p6 and p7 were accidently removed from N2798.
7542</li>
7543<li>
7544Issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#929">929</a> argues for a way to pass by &amp;&amp; for
7545efficiency but retain the decaying behavior of pass by value for the
7546<tt>thread</tt> constructor.  That same solution is applicable here.
7547</li>
7548</ol>
7549</blockquote>
7550
7551<p><i>[
7552Batavia (2009-05):
7553]</i></p>
7554
7555<blockquote>
7556<p>
7557We were going to recommend moving this issue to Tentatively Ready
7558until we noticed potential overlap with issue 816 (q.v.).
7559</p>
7560<p>
7561Move to Open,
7562and recommend both issues be considered together
7563(and possibly merged).
7564</p>
7565</blockquote>
7566
7567<p><i>[
75682009-07 Frankfurt:
7569]</i></p>
7570
7571
7572<blockquote>
7573The proposed resolution uses concepts. Leave Open.
7574</blockquote>
7575
7576<p><i>[
75772009-10 Santa Cruz:
7578]</i></p>
7579
7580
7581<blockquote>
7582Leave as Open. Howard to provide deconceptified wording.
7583</blockquote>
7584
7585<p><i>[
75862009-11-07 Howard updates wording.
7587]</i></p>
7588
7589
7590
7591
7592<p><b>Proposed resolution:</b></p>
7593<p>
7594Change 20.7 [function.objects] p2:
7595</p>
7596
7597<blockquote><pre>template&lt;class F<del>n</del>, class... <del>Types</del> <ins>BoundArgs</ins>&gt;
7598  <i>unspecified</i> bind(F<del>n</del><ins>&amp;&amp;</ins>, <del>Types</del> <ins>BoundArgs&amp;&amp;</ins>...);
7599template&lt;class R, class F<del>n</del>, class... <del>Types</del> <ins>BoundArgs</ins>&gt;
7600  <i>unspecified</i> bind(F<del>n</del><ins>&amp;&amp;</ins>, <del>Types</del> <ins>BoundArgs&amp;&amp;</ins>...);
7601</pre></blockquote>
7602
7603<p>
7604Change 20.7.11.1.3 [func.bind.bind]:
7605</p>
7606
7607<blockquote>
7608<p><ins>
7609Within this clause:
7610</ins></p>
7611
7612<ul>
7613<li><ins>
7614Let <tt>FD</tt> be a synonym for the type <tt>decay&lt;F&gt;::type</tt>.
7615</ins></li>
7616<li><ins>
7617Let <tt>fd</tt> be an lvalue of type <tt>FD</tt> constructed from
7618<tt>std::forward&lt;F&gt;(f)</tt>.
7619</ins></li>
7620<li><ins>
7621Let <tt>Ti</tt> be a synonym for the i<sup><i>th</i></sup> type in the
7622parameter pack <tt>BoundArgs</tt>.
7623</ins></li>
7624<li><ins>
7625Let <tt>TiD</tt> be a synonym for the type <tt>decay&lt;Ti&gt;::type</tt>.
7626</ins></li>
7627<li><ins>
7628Let <tt>ti</tt> be the i<sup><i>th</i></sup> argument in <tt>bound_args</tt>.
7629</ins></li>
7630<li><ins>
7631Let <tt>tid</tt> be an lvalue of type <tt>TiD</tt> constructed from
7632<tt>std::forward&lt;Ti&gt;(ti)</tt>.
7633</ins></li>
7634</ul>
7635
7636<pre>template&lt;class F, class... BoundArgs&gt;
7637  <i>unspecified</i> bind(F<ins>&amp;&amp;</ins> f, BoundArgs<ins>&amp;&amp;</ins>... bound_args);
7638</pre>
7639
7640<blockquote>
7641<p>
7642-1- <i>Requires:</i>
7643<ins><tt>is_constructible&lt;FD, F&gt;::value</tt>
7644shall be <tt>true</tt>.</ins>
7645<ins><tt>is_constructible&lt;TiD, Ti&gt;::value</tt>
7646shall be <tt>true</tt></ins>.
7647<del><tt>F</tt> and each <tt>Ti</tt> in
7648<tt>BoundArgs</tt> shall be CopyConstructible.</del>
7649<tt><i>INVOKE</i>(f<ins>d</ins>, w1, w2, ..., wN)</tt> (20.7.2 [func.require]) shall be a valid expression for some values
7650<i>w1, w2, ..., wN</i>, where <tt>N == sizeof...(bound_args)</tt>.
7651</p>
7652<p>
7653-2- <i>Returns:</i> A forwarding call wrapper <tt>g</tt> with a weak
7654result type (20.7.2 [func.require]). The effect of <tt>g(u1, u2,
7655..., uM)</tt> shall be <tt><i>INVOKE</i>(f<ins>d</ins>, v1, v2, ..., vN,
7656result_of&lt;F<ins>D</ins> <i>cv</i> (V1, V2, ..., VN)&gt;::type)</tt>, where
7657<i>cv</i> represents the <i>cv</i>-qualifiers of <tt>g</tt> and the
7658values and types of the bound arguments <tt>v1, v2, ..., vN</tt> are
7659determined as specified below.
7660<ins>The copy constructor and move constructor of the forwarding call wrapper shall throw an
7661exception if and only if the corresponding constructor of <tt>FD</tt> or any of the types
7662<tt>TiD</tt> throw an exception.</ins>
7663</p>
7664<p>
7665-3- <i>Throws:</i> Nothing unless the <del>copy</del>
7666construct<ins>ion</ins><del>or</del> of
7667<tt><del>F</del><ins>fd</ins></tt> or of one of the <ins>values
7668<tt>tid</tt></ins> <del>types in the <tt>BoundArgs...</tt> pack
7669expansion</del> throws an exception.
7670</p>
7671<p>
7672<ins>
7673<i>Remarks:</i> The <i>unspecified</i> return type shall be
7674<tt>MoveConstructible</tt>.  If all of <tt>FD</tt> and <tt>TiD</tt> are
7675<tt>CopyConstructible</tt> then the <i>unspecified</i> return type shall
7676be <tt>CopyConstructible</tt>. [<i>Note:</i> This implies that all of
7677<tt>FD</tt> and <tt>TiD</tt> shall be <tt>MoveConstructible</tt> &#8212;
7678<i>end note</i>]
7679</ins>
7680</p>
7681</blockquote>
7682
7683<pre>template&lt;class R, class F, class... BoundArgs&gt;
7684  <i>unspecified</i> bind(F<ins>&amp;&amp;</ins> f, BoundArgs<ins>&amp;&amp;</ins>... bound_args);
7685</pre>
7686
7687<blockquote>
7688<p>
7689-4- <i>Requires:</i>
7690<ins><tt>is_constructible&lt;FD, F&gt;::value</tt>
7691shall be <tt>true</tt>.</ins>
7692<ins><tt>is_constructible&lt;TiD, Ti&gt;::value</tt>
7693shall be <tt>true</tt></ins>.
7694<del><tt>F</tt> and each <tt>Ti</tt> in
7695<tt>BoundArgs</tt> shall be CopyConstructible.</del>
7696<tt><i>INVOKE</i>(f<ins>d</ins>, w1,
7697w2, ..., wN)</tt> shall be a valid expression for some values <i>w1, w2,
7698..., wN</i>, where <tt>N == sizeof...(bound_args)</tt>.
7699</p>
7700<p>
7701-5- <i>Returns:</i> A forwarding call wrapper <tt>g</tt> with a nested
7702type <tt>result_type</tt> defined as a synonym for <tt>R</tt>. The
7703effect of <tt>g(u1, u2, ..., uM)</tt> shall be <tt><i>INVOKE</i>(f<ins>d</ins>, v1,
7704v2, ..., vN, R)</tt>, where the values and types of the bound arguments
7705<tt>v1, v2, ..., vN</tt> are determined as specified below.
7706<ins>The copy constructor and move constructor of the forwarding call wrapper shall throw an
7707exception if and only if the corresponding constructor of <tt>FD</tt> or any of the types
7708<tt>TiD</tt> throw an exception.</ins>
7709</p>
7710<p>
7711-6- <i>Throws:</i> Nothing unless the <del>copy</del>
7712construct<ins>ion</ins><del>or</del> of
7713<tt><del>F</del><ins>fd</ins></tt> or of one of the <ins>values
7714<tt>tid</tt></ins> <del>types in the <tt>BoundArgs...</tt> pack
7715expansion</del> throws an exception.
7716</p>
7717<p>
7718<ins>
7719<i>Remarks:</i> The <i>unspecified</i> return type shall be
7720<tt>MoveConstructible</tt>.  If all of <tt>FD</tt> and <tt>TiD</tt> are
7721<tt>CopyConstructible</tt> then the <i>unspecified</i> return type shall
7722be <tt>CopyConstructible</tt>. [<i>Note:</i> This implies that all of
7723<tt>FD</tt> and <tt>TiD</tt> shall be <tt>MoveConstructible</tt> &#8212;
7724<i>end note</i>]
7725</ins>
7726</p>
7727</blockquote>
7728
7729<p>
7730-7- The values of the <i>bound arguments</i> <tt>v1, v2, ..., vN</tt> and
7731their corresponding types <tt>V1, V2, ..., VN</tt> depend on the type<ins>s
7732<tt>TiD</tt> derived from</ins>
7733<del>of the corresponding argument <tt>ti</tt> in <tt>bound_args</tt> of type
7734<tt>Ti</tt> in <tt>BoundArgs</tt> in</del>
7735the call to <tt>bind</tt> and the
7736<i>cv</i>-qualifiers <i>cv</i> of the call wrapper <tt>g</tt> as
7737follows:
7738</p>
7739
7740<ul>
7741<li>
7742if <tt><del>ti</del> <ins>TiD</ins></tt> <del>is of</del> <ins>has</ins>
7743type <tt>reference_wrapper&lt;T&gt;</tt> the argument is
7744<tt>ti<ins>d</ins>.get()</tt> and its type <tt>Vi</tt> is
7745<tt>T&amp;</tt>;
7746</li>
7747<li>
7748if the value of
7749<tt>std::is_bind_expression&lt;Ti<ins>D</ins>&gt;::value</tt> is
7750<tt>true</tt> the argument is <tt>ti<ins>d</ins>(u1, u2, ..., uM)</tt>
7751and its type <tt>Vi</tt> is <tt>result_of&lt;Ti<ins>D</ins> <i>cv</i>
7752(U1&amp;, U2&amp;, ..., UM&amp;)&gt;::type</tt>;
7753</li>
7754<li>
7755if the value <tt>j</tt> of
7756<tt>std::is_placeholder&lt;Ti<ins>D</ins>&gt;::value</tt> is not zero
7757the argument is <tt>std::forward&lt;Uj&gt;(uj)</tt> and its type
7758<tt>Vi</tt> is <tt>Uj&amp;&amp;</tt>;
7759</li>
7760<li>
7761otherwise the value is <tt>ti<ins>d</ins></tt> and its type <tt>Vi</tt>
7762is <tt>Ti<ins>D</ins> <i>cv</i> &amp;</tt>.
7763</li>
7764</ul>
7765
7766</blockquote>
7767
7768
7769
7770
7771
7772
7773<hr>
7774<h3><a name="819"></a>819. rethrow_if_nested</h3>
7775<p><b>Section:</b> 18.8.6 [except.nested] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
7776 <b>Submitter:</b> Alisdair Meredith <b>Opened:</b> 2008-03-25  <b>Last modified:</b> 2009-10-23</p>
7777<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#except.nested">active issues</a> in [except.nested].</p>
7778<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#except.nested">issues</a> in [except.nested].</p>
7779<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
7780<p><b>Discussion:</b></p>
7781<p>
7782Looking at the wording I submitted for <tt>rethrow_if_nested</tt>, I don't think I
7783got it quite right.
7784</p>
7785
7786<p>
7787The current wording says:
7788</p>
7789
7790<blockquote>
7791<pre>template &lt;class E&gt; void rethrow_if_nested(const E&amp; e);
7792</pre>
7793<blockquote>
7794<p>
7795<i>Effects:</i> Calls <tt>e.rethrow_nested()</tt> only if <tt>e</tt>
7796is publicly derived from <tt>nested_exception</tt>.
7797</p>
7798</blockquote>
7799</blockquote>
7800
7801<p>
7802This is trying to be a bit subtle, by requiring <tt>e</tt> (not <tt>E</tt>) to be publicly
7803derived from <tt>nested_exception</tt> the idea is that a <tt>dynamic_cast</tt> would be
7804required to be sure.  Unfortunately, if <tt>e</tt> is dynamically but not statically
7805derived from <tt>nested_exception</tt>, <tt>e.rethrow_nested()</tt> is ill-formed.
7806</p>
7807
7808<p><i>[
7809San Francisco:
7810]</i></p>
7811
7812
7813<blockquote>
7814Alisdair was volunteered to provide wording.
7815</blockquote>
7816
7817<p><i>[
78182009-10 Santa Cruz:
7819]</i></p>
7820
7821
7822<blockquote>
7823Leave as Open. Alisdair to provide wording.
7824</blockquote>
7825
7826
7827
7828<p><b>Proposed resolution:</b></p>
7829
7830
7831
7832
7833
7834<hr>
7835<h3><a name="834"></a>834. Unique_ptr::pointer requirements underspecified</h3>
7836<p><b>Section:</b> 20.8.14.2 [unique.ptr.single] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
7837 <b>Submitter:</b> Daniel Kr�gler <b>Opened:</b> 2008-05-14  <b>Last modified:</b> 2009-10-26</p>
7838<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#unique.ptr.single">active issues</a> in [unique.ptr.single].</p>
7839<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#unique.ptr.single">issues</a> in [unique.ptr.single].</p>
7840<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
7841<p><b>Discussion:</b></p>
7842<p>
7843Issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#673">673</a> (including recent updates by <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#821">821</a>) proposes a useful
7844extension point for <tt>unique_ptr</tt> by granting support for an optional
7845<tt>deleter_type::pointer</tt> to act as pointer-like replacement for <tt>element_type*</tt>
7846(In the following: <tt>pointer</tt>).
7847</p>
7848<p>
7849Unfortunately no requirements are specified for the type <tt>pointer</tt> which has
7850impact on at least two key features of <tt>unique_ptr</tt>:
7851</p>
7852
7853<ol>
7854<li>Operational fail-safety.</li>
7855<li>(Well-)Definedness of expressions.</li>
7856</ol>
7857
7858<p>
7859<tt>Unique_ptr</tt> specification makes great efforts to require that essentially *all*
7860operations cannot throw and therefore adds proper wording to the affected
7861operations of the deleter as well. If user-provided <tt>pointer</tt>-emulating types
7862("smart pointers") will be allowed, either *all* throw-nothing clauses have to
7863be replaced by weaker "An exception is thrown only if <tt>pointer</tt>'s {op} throws
7864an exception"-clauses or it has to be said explicitly that all used
7865operations of
7866<tt>pointer</tt> are required *not* to throw. I understand the main focus of <tt>unique_ptr</tt>
7867to be as near as possible to the advantages of native pointers which cannot
7868fail and thus strongly favor the second choice. Also, the alternative position
7869would make it much harder to write safe and simple template code for
7870<tt>unique_ptr</tt>. Additionally, I assume that a general statement need to be given
7871that all of the expressions of <tt>pointer</tt> used to define semantics are required to
7872be well-formed and well-defined (also as back-end for <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#762">762</a>).
7873</p>
7874
7875<p><i>[
7876Sophia Antipolis:
7877]</i></p>
7878
7879
7880<blockquote>
7881<p>
7882Howard: We maybe need a core concept <tt>PointerLike</tt>, but we don't need the
7883arithmetic (see <tt>shared_ptr</tt> vs. <tt>vector&lt;T&gt;::iterator</tt>.
7884</p>
7885<p>
7886Howard will go through and enumerate the individual requirements wrt. <tt>pointer</tt> for each member function.
7887</p>
7888</blockquote>
7889
7890<p><i>[
78912009-07 Frankfurt:
7892]</i></p>
7893
7894
7895<blockquote>
7896Move to Ready.
7897</blockquote>
7898
7899<p><i>[
79002009-10-15 Alisdair pulls from Ready:
7901]</i></p>
7902
7903
7904<blockquote>
7905<p>
7906I hate to pull an issue out of Ready status, but I don't think 834 is
7907fully baked yet.
7908</p>
7909
7910<p>
7911For reference the proposed resolution is to add the following words:
7912</p>
7913
7914<blockquote>
7915<tt>unique_ptr&lt;T, D&gt;::pointer</tt>'s operations shall be
7916well-formed, shall have well defined behavior, and shall not throw
7917exceptions.
7918</blockquote>
7919
7920<p>
7921This leaves me with a big question : which operations?
7922</p>
7923
7924<p>
7925Are all pointer operations required to be nothrow, including operations
7926that have nothing to do with interactions with <tt>unique_ptr</tt>?  This was
7927much simpler with concepts where we could point to operations within a
7928certain concept, and so nail down the interactions.
7929</p>
7930</blockquote>
7931
7932<p><i>[
79332009-10-15 Daniel adds:
7934]</i></p>
7935
7936
7937<blockquote>
7938I volunteer to prepare a more fine-grained solution, but I would like
7939to ask for feedback that helps me doing so. If this question is asked
7940early in the meeting I might be able to fix it within the week, but I
7941cannot promise that now.
7942</blockquote>
7943
7944<p><i>[
79452009-10 Santa Cruz:
7946]</i></p>
7947
7948
7949<blockquote>
7950Leave in open. Daniel to provide wording as already suggested.
7951</blockquote>
7952
7953
7954
7955
7956<p><b>Proposed resolution:</b></p>
7957<p>
7958Add the following sentence just at the end of the newly proposed
795920.8.14.2 [unique.ptr.single]/p. 3:
7960</p>
7961
7962<blockquote>
7963<tt>unique_ptr&lt;T, D&gt;::pointer</tt>'s operations shall be well-formed, shall have well
7964defined behavior, and shall not throw exceptions.
7965</blockquote>
7966
7967
7968
7969
7970
7971<hr>
7972<h3><a name="835"></a>835. tying two streams together (correction to DR 581)</h3>
7973<p><b>Section:</b> 27.5.4.2 [basic.ios.members] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
7974 <b>Submitter:</b> Martin Sebor <b>Opened:</b> 2008-05-17  <b>Last modified:</b> 2009-10-20</p>
7975<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#basic.ios.members">active issues</a> in [basic.ios.members].</p>
7976<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#basic.ios.members">issues</a> in [basic.ios.members].</p>
7977<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
7978<p><b>Discussion:</b></p>
7979       <p>
7980
7981The fix for
7982issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#581">581</a>,
7983now integrated into the working paper, overlooks a couple of minor
7984problems.
7985
7986       </p>
7987       <p>
7988
7989First, being an unformatted function once again, <code>flush()</code>
7990is required to create a sentry object whose constructor must, among
7991other things, flush the tied stream. When two streams are tied
7992together, either directly or through another intermediate stream
7993object, flushing one will also cause a call to <code>flush()</code> on
7994the other tied stream(s) and vice versa, ad infinitum. The program
7995below demonstrates the problem.
7996
7997       </p>
7998       <p>
7999
8000Second, as Bo Persson notes in his
8001comp.lang.c++.moderated <a href="http://groups.google.com/group/comp.lang.c++.moderated/tree/browse_frm/thread/f2187794e9cc036d/305df31dc583054a">post</a>,
8002for streams with the <code>unitbuf</code> flag set such
8003as <code>std::stderr</code>, the destructor of the sentry object will
8004again call <code>flush()</code>. This seems to create an infinite
8005recursion for <code>std::cerr &lt;&lt; std::flush;</code>
8006
8007       </p>
8008       <blockquote>
8009           <pre>#include &lt;iostream&gt;
8010
8011int main ()
8012{
8013   std::cout.tie (&amp;std::cerr);
8014   std::cerr.tie (&amp;std::cout);
8015   std::cout &lt;&lt; "cout\n";
8016   std::cerr &lt;&lt; "cerr\n";
8017} 
8018</pre>
8019</blockquote>
8020
8021<p><i>[
8022Batavia (2009-05):
8023]</i></p>
8024
8025<blockquote>
8026We agree with the proposed resolution.
8027Move to Review.
8028</blockquote>
8029
8030<p><i>[
80312009-05-26 Daniel adds:
8032]</i></p>
8033
8034
8035<blockquote>
8036<p>
8037I think that the most recently suggested change in
803827.7.2.4 [ostream::sentry] need some further word-smithing. As
8039written, it would make the behavior undefined, if under
8040conditions when <tt>pubsync()</tt> should be called, but when
8041in this scenario <tt>os.rdbuf()</tt> returns 0.
8042</p>
8043<p>
8044This case is explicitly handled in <tt>flush()</tt> and needs to be
8045taken care of. My suggested fix is:
8046</p>
8047
8048<blockquote>
8049If <tt>((os.flags() &amp; ios_base::unitbuf) &amp;&amp; !uncaught_exception()</tt>
8050<ins><tt>&amp;&amp; os.rdbuf() != 0</tt></ins>) is true, calls <del><tt>os.flush()</tt></del>
8051<ins><tt>os.rdbuf()-&gt;pubsync()</tt></ins>.
8052</blockquote>
8053
8054<p>
8055Two secondary questions are:
8056</p>
8057
8058<ol>
8059<li>
8060Should <tt>pubsync()</tt> be invoked in any case or shouldn't a
8061base requirement for this trial be that <tt>os.good() == true</tt>
8062as required in the original <tt>flush()</tt> case?
8063</li>
8064<li>
8065Since <tt>uncaught_exception()</tt> is explicitly tested, shouldn't
8066a return value of -1 of <tt>pubsync()</tt> produce <tt>setstate(badbit)</tt>
8067(which may throw <tt>ios_base::failure</tt>)?
8068</li>
8069</ol>
8070</blockquote>
8071
8072<p><i>[
80732009-07 Frankfurt:
8074]</i></p>
8075
8076
8077<blockquote>
8078<p>
8079Daniel volunteered to modify the proposed resolution to address his two questions.
8080</p>
8081<p>
8082Move back to Open.
8083</p>
8084</blockquote>
8085
8086<p><i>[
80872009-07-26 Daniel provided wording.  Moved to Review.
8088]</i></p>
8089
8090
8091<p><i>[
80922009-10-13 Daniel adds:
8093]</i></p>
8094
8095
8096<blockquote>
8097This proposed wording is written to match the outcome
8098of <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#397">397</a>.
8099</blockquote>
8100
8101<p><i>[
81022009 Santa Cruz:
8103]</i></p>
8104
8105
8106<blockquote>
8107Move to Open. Martin to propose updated wording that will also resolve
8108issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#397">397</a> consistently.
8109</blockquote>
8110
8111
8112
8113<p><b>Proposed resolution:</b></p>
8114<p><i>[
8115based on
8116<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2960.pdf">N2960</a>
8117numbering
8118]</i></p>
8119
8120
8121<ol>
8122<li>
8123<p>
8124Just before 27.5.4.2 [basic.ios.members]/2 insert a new paragraph:
8125</p>
8126
8127<blockquote>
8128<ins><i>Requires:</i> If <tt>(tiestr != 0)</tt> is <tt>true</tt>, <tt>tiestr</tt> must not be reachable
8129by traversing the linked list of tied stream objects starting from
8130<tt>tiestr-&gt;tie()</tt>.</ins>
8131</blockquote>
8132</li>
8133
8134<li>
8135<p>
8136Change 27.7.2.4 [ostream::sentry]/4 as indicated:
8137</p>
8138
8139<blockquote>
8140If <tt>((os.flags() &amp; ios_base::unitbuf) &amp;&amp; !uncaught_exception()<ins>&amp;&amp;
8141os.good()</ins>)</tt> is <tt>true</tt>, calls <del><tt>os.flush()</tt></del>
8142<ins><tt>os.rdbuf()-&gt;pubsync()</tt>. If that function returns -1 sets
8143<tt>badbit</tt> in <tt>os.rdstate()</tt> without propagating an exception</ins>.
8144</blockquote>
8145</li>
8146
8147</ol>
8148
8149
8150   
8151
8152
8153
8154<hr>
8155<h3><a name="836"></a>836. 
8156       effects of <code>money_base::space</code> and
8157       <code>money_base::none</code> on <code>money_get</code>
8158   </h3>
8159<p><b>Section:</b> 22.4.6.1.2 [locale.money.get.virtuals] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
8160 <b>Submitter:</b> Martin Sebor <b>Opened:</b> 2008-05-17  <b>Last modified:</b> 2009-10-21</p>
8161<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#locale.money.get.virtuals">issues</a> in [locale.money.get.virtuals].</p>
8162<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
8163<p><b>Duplicate of:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#670">670</a></p>
8164<p><b>Discussion:</b></p>
8165
8166       <p>
8167
8168In paragraph 2, 22.4.6.1.2 [locale.money.get.virtuals] specifies the following:
8169
8170       </p>
8171       <blockquote>
8172
8173Where <code>space</code> or <code>none</code> appears in the format
8174pattern, except at the end, optional white space (as recognized
8175by <code>ct.is</code>) is consumed after any required space.
8176
8177       </blockquote>
8178       <p>
8179
8180This requirement can be (and has been) interpreted two mutually
8181exclusive ways by different readers. One possible interpretation
8182is that:
8183
8184       </p>
8185       <blockquote>
8186           <ol>
8187               <li>
8188
8189where <code>money_base::space</code> appears in the format, at least
8190one space is required, and
8191
8192               </li>
8193               <li>
8194
8195where <code>money_base::none</code> appears in the format, space is
8196allowed but not required.
8197
8198               </li>
8199           </ol>
8200       </blockquote>
8201       <p>
8202
8203The other is that:
8204
8205       </p>
8206       <blockquote>
8207
8208where either <code>money_base::space</code> or <code>money_base::none</code> appears in the format, white space is optional.
8209
8210       </blockquote>
8211
8212<p><i>[
8213San Francisco:
8214]</i></p>
8215
8216
8217<blockquote>
8218Martin will revise the proposed resolution.
8219</blockquote>
8220
8221<p><i>[
82222009-07 Frankfurt:
8223]</i></p>
8224
8225
8226<blockquote>
8227<p>
8228There is a noun missing from the proposed resolution. It's not clear
8229that the last sentence would be helpful, even if the word were not
8230missing:
8231</p>
8232<blockquote>
8233In either case, any required MISSINGWORD followed by all optional whitespace (as recognized by ct.is()) is consumed.
8234</blockquote>
8235<p>
8236Strike this sentence and move to Review.
8237</p>
8238
8239<p><i>[
8240Howard: done.
8241]</i></p>
8242
8243</blockquote>
8244
8245<p><i>[
82462009-10 Santa Cruz:
8247]</i></p>
8248
8249
8250<blockquote>
8251Move to Ready.
8252</blockquote>
8253
8254   
8255
8256   <p><b>Proposed resolution:</b></p>
8257       <p>
8258
8259I propose to change the text to make it clear that the first
8260interpretation is intended, that is, to make following change to
826122.4.6.1.2 [locale.money.get.virtuals], p2:
8262
8263       </p>
8264
8265       <blockquote>
8266
8267When <code><ins>money_base::</ins>space</code>
8268or <code><ins>money_base::</ins>none</code> appears <ins>as the last
8269element </ins>in the format pattern, <del>except at the end, optional
8270white space (as recognized by <code>ct.is</code>) is consumed after
8271any required space.</del> <ins>no white space is consumed. Otherwise,
8272where <code>money_base::space</code> appears in any of the initial
8273elements of the format pattern, at least one white space character is
8274required. Where <code>money_base::none</code> appears in any of the
8275initial elements of the format pattern, white space is allowed but not
8276required.</ins>
8277If <code>(str.flags() &amp; str.showbase)</code> is <code>false</code>, ...
8278
8279       </blockquote>
8280   
8281
8282
8283
8284<hr>
8285<h3><a name="854"></a>854. <tt>default_delete</tt> converting constructor underspecified</h3>
8286<p><b>Section:</b> 20.8.14.1.1 [unique.ptr.dltr.dflt] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
8287 <b>Submitter:</b> Howard Hinnant <b>Opened:</b> 2008-06-18  <b>Last modified:</b> 2009-10-21</p>
8288<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
8289<p><b>Discussion:</b></p>
8290<p>
8291No relationship between <tt>U</tt> and <tt>T</tt> in the converting constructor for <tt>default_delete</tt> template.
8292</p>
8293<p>
8294Requirements: <tt>U*</tt> is convertible to <tt>T*</tt> and <tt>has_virtual_destructor&lt;T&gt;</tt>;
8295the latter should also become a concept.
8296</p>
8297<p>
8298Rules out cross-casting.
8299</p>
8300<p>
8301The requirements for <tt>unique_ptr</tt> conversions should be the same as those on the deleter.
8302</p>
8303
8304<p><i>[
8305Howard adds 2008-11-26:
8306]</i></p>
8307
8308
8309<blockquote>
8310<p>
8311I believe we need to be careful to not outlaw the following use case, and
8312I believe the current proposed wording
8313(<tt>requires Convertible&lt;U*, T*&gt; &amp;&amp; HasVirtualDestructor&lt;T&gt;</tt>) does so:
8314</p>
8315
8316<blockquote><pre>#include &lt;memory&gt;
8317
8318int main()
8319{
8320    std::unique_ptr&lt;int&gt; p1(new int(1));
8321    std::unique_ptr&lt;const int&gt; p2(move(p1));
8322    int i = *p2;
8323<font color="#c80000">//    *p2 = i;  // should not compile</font>
8324}
8325</pre></blockquote>
8326
8327<p>
8328I've removed "<tt>&amp;&amp; HasVirtualDestructor&lt;T&gt;</tt>" from the
8329<tt>requires</tt> clause in the proposed wording.
8330</p>
8331
8332</blockquote>
8333
8334<p><i>[
8335Post Summit:
8336]</i></p>
8337
8338
8339<blockquote>
8340<p>
8341Alisdair: This issue has to stay in review pending a paper constraining
8342<tt>unique_ptr</tt>.
8343</p>
8344<p>
8345Consensus: We agree with the resolution, but <tt>unique_ptr</tt> needs
8346to be constrained, too.
8347</p>
8348<p>
8349Recommend Keep in Review.
8350</p>
8351</blockquote>
8352
8353<p><i>[
8354Batavia (2009-05):
8355]</i></p>
8356
8357<blockquote>
8358Keep in Review status for the reasons cited.
8359</blockquote>
8360
8361<p><i>[
83622009-07 Frankfurt:
8363]</i></p>
8364
8365
8366<blockquote>
8367<p>
8368The proposed resolution uses concepts. Howard needs to rewrite the
8369proposed resolution.
8370</p>
8371<p>
8372Move back to Open.
8373</p>
8374</blockquote>
8375
8376<p><i>[
83772009-07-26 Howard provided rewritten proposed wording and moved to Review.
8378]</i></p>
8379
8380
8381<p><i>[
83822009-10 Santa Cruz:
8383]</i></p>
8384
8385
8386<blockquote>
8387Move to Ready.
8388</blockquote>
8389
8390
8391
8392<p><b>Proposed resolution:</b></p>
8393<p>
8394Add after 20.8.14.1.1 [unique.ptr.dltr.dflt], p1:
8395</p>
8396
8397<blockquote><pre>template &lt;class U&gt; default_delete(const default_delete&lt;U&gt;&amp; other);
8398</pre>
8399<blockquote>
8400<p>
8401-1- <i>Effects:</i> ...
8402</p>
8403<p><ins>
8404<i>Remarks:</i> This constructor shall participate in overload resolution
8405if and only if <tt>U*</tt> is implicitly convertible to <tt>T*</tt>.
8406</ins></p>
8407</blockquote>
8408</blockquote>
8409
8410
8411
8412
8413
8414
8415<hr>
8416<h3><a name="860"></a>860. Floating-Point State</h3>
8417<p><b>Section:</b> 26 [numerics] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
8418 <b>Submitter:</b> Lawrence Crowl <b>Opened:</b> 2008-06-23  <b>Last modified:</b> 2009-10-23</p>
8419<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#numerics">issues</a> in [numerics].</p>
8420<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
8421<p><b>Discussion:</b></p>
8422<p>
8423There are a number of functions that affect the floating point state.
8424These function need to be thread-safe, but I'm unsure of the right
8425approach in the standard, as we inherit them from C.
8426</p>
8427
8428<p><i>[
8429San Francisco:
8430]</i></p>
8431
8432
8433<blockquote>
8434<p>
8435Nick: I think we already say that these functions do not introduce data
8436races; see 17.6.5.6/20
8437</p>
8438<p>
8439Pete: there's more to it than not introducing data races; are these
8440states maintained per thread?
8441</p>
8442<p>
8443Howard: 21.5/14 says that strtok and strerror are not required to avoid
8444data races, and 20.9/2 says the same about asctime, gmtime, ctime, and
8445gmtime.
8446</p>
8447<p>
8448Nick: POSIX has a list of not-safe functions. All other functions are
8449implicitly thread safe.
8450</p>
8451<p>
8452Lawrence is to form a group between meetings to attack this issue. Nick
8453and Tom volunteered to work with Lawrence.
8454</p>
8455<p>
8456Move to Open.
8457</p>
8458</blockquote>
8459
8460<p><i>[
8461Post Summit:
8462]</i></p>
8463
8464
8465<blockquote>
8466<p>
8467Hans: Sane oses seem ok. Sensible thing is implementable and makes sense.
8468</p>
8469<p>
8470Nick: Default wording seems to cover this? Hole in POSIX, these
8471functions need to be added to list of thread-unsafe functions.
8472</p>
8473<p>
8474Lawrence: Not sufficient, not "thread-safe" per our definition, but
8475think of state as a thread-local variable. Need something like "these
8476functions only affect state in the current thread."
8477</p>
8478<p>
8479Hans: Suggest the following wording: "The floating point environment is
8480maintained per-thread."
8481</p>
8482<p>
8483Walter: Any other examples of state being thread safe that are not
8484already covered elsewhere?
8485</p>
8486<p>
8487Have thread unsafe functions paper which needs to be updated. Should
8488just fold in 26.3 [cfenv] functions.
8489</p>
8490<p>
8491Recommend Open. Lawrence instead suggests leaving it open until we have
8492suitable wording that may or may not include the thread local
8493commentary.
8494</p>
8495</blockquote>
8496
8497<p><i>[
84982009-09-23 Hans provided wording.
8499]</i></p>
8500
8501
8502<blockquote>
8503If I understand the history correctly, Nick, as the Posix liaison,
8504should probably get a veto on this, since I think it came from Posix (?)
8505via WG14 and should probably really be addressed there (?).  But I think
8506we are basically in agreement that there is no other sane way to do
8507this, and hence we don't have to worry too much about stepping on toes. 
8508As far as I can tell, this same issue also exists in the latest Posix
8509standard (?).
8510</blockquote>
8511
8512<p><i>[
85132009-10 Santa Cruz:
8514]</i></p>
8515
8516
8517<blockquote>
8518Moved to Ready.
8519</blockquote>
8520
8521
8522
8523<p><b>Proposed resolution:</b></p>
8524<p>
8525Add at the end of 26.3.1 [cfenv.syn]:
8526</p>
8527
8528<blockquote>
8529<p>
85302 The header defines all functions, types, and macros the same as C99 7.6.
8531</p>
8532
8533<p><ins>
8534A separate floating point environment shall be maintained for each
8535thread.  Each function accesses the environment corresponding to its
8536calling thread.
8537</ins></p>
8538</blockquote>
8539
8540
8541
8542
8543
8544<hr>
8545<h3><a name="861"></a>861. Incomplete specification of EqualityComparable for std::forward_list</h3>
8546<p><b>Section:</b> 23.2 [container.requirements] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
8547 <b>Submitter:</b> Daniel Kr�gler <b>Opened:</b> 2008-06-24  <b>Last modified:</b> 2009-10-24</p>
8548<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#container.requirements">active issues</a> in [container.requirements].</p>
8549<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#container.requirements">issues</a> in [container.requirements].</p>
8550<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
8551<p><b>Discussion:</b></p>
8552<p>
8553Table 89, Container requirements, defines <tt>operator==</tt> in terms of the container
8554member function <tt>size()</tt> and the algorithm <tt>std::equal</tt>:
8555</p>
8556
8557<blockquote>
8558<tt>==</tt> is an equivalence relation. <tt>a.size() == b.size() &amp;&amp;
8559equal(a.begin(), a.end(), b.begin()</tt>
8560</blockquote>
8561
8562<p>
8563The new container <tt>forward_list</tt> does not provide a <tt>size</tt> member function
8564by design but does provide <tt>operator==</tt> and <tt>operator!=</tt> without specifying it's semantic.
8565</p>
8566<p>
8567Other parts of the (sequence) container requirements do also depend on
8568<tt>size()</tt>, e.g. <tt>empty()</tt>
8569or <tt>clear()</tt>, but this issue explicitly attempts to solve the missing
8570<tt>EqualityComparable</tt> specification,
8571because of the special design choices of <tt>forward_list</tt>.
8572</p>
8573<p>
8574I propose to apply one of the following resolutions, which are described as:
8575</p>
8576
8577<ol type="A">
8578<li>
8579Provide a definition, which is optimal for this special container without
8580previous size test. This choice prevents two <tt>O(N)</tt> calls of <tt>std::distance()</tt>
8581with the corresponding container ranges and instead uses a special
8582<tt>equals</tt> implementation which takes two container ranges instead of 1 1/2.
8583</li>
8584<li>
8585The simple fix where the usual test is adapted such that <tt>size()</tt> is replaced
8586by <tt>distance</tt> with corresponding performance disadvantages.
8587</li>
8588</ol>
8589<p>
8590Both proposal choices are discussed, the preferred choice of the author is
8591to apply (A).
8592</p>
8593
8594<p><i>[
8595San Francisco:
8596]</i></p>
8597
8598
8599<blockquote>
8600<p>
8601There's an Option C: change the requirements table to use distance().
8602</p>
8603<p>
8604LWG found Option C acceptable.
8605</p>
8606<p>
8607Martin will draft the wording for Option C.
8608</p>
8609</blockquote>
8610
8611<p><i>[
8612post San Francisco:
8613]</i></p>
8614
8615
8616<blockquote>
8617Martin provided wording for Option C.
8618</blockquote>
8619
8620<p><i>[
86212009-07 Frankfurt
8622]</i></p>
8623
8624
8625<blockquote>
8626<p>
8627Other operational semantics (see, for example, Tables 82 and 83) are
8628written in terms of a container's size() member. Daniel to update
8629proposed resolution C.
8630</p>
8631<p><i>[
8632Howard: Commented out options A and B.
8633]</i></p>
8634
8635</blockquote>
8636
8637<p><i>[
86382009-07-26 Daniel updated proposed resolution C.
8639]</i></p>
8640
8641
8642<p><i>[
86432009-10 Santa Cruz:
8644]</i></p>
8645
8646
8647<blockquote>
8648Mark NAD Editorial. Addressed by
8649<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2986.pdf">N2986</a>.
8650</blockquote>
8651
8652<p><i>[
86532009-10 Santa Cruz:
8654]</i></p>
8655
8656
8657<blockquote>
8658Reopened.
8659<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2986.pdf">N2986</a>
8660was rejected in full committee on procedural grounds.
8661</blockquote>
8662
8663
8664
8665<p><b>Proposed resolution:</b></p>
8666
8667
8668<p>
8669Option (C):
8670</p>
8671<blockquote>
8672
8673<p><i>[
8674The changes are relative to
8675<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2914.pdf">N2914</a>
8676but concept-free.
8677]</i></p>
8678
8679
8680<ol>
8681<li>
8682<p>
8683In 23.2.1 [container.requirements.general] change Table 80 -- Container requirements as indicated:
8684</p>
8685
8686<ol type="a">
8687<li>
8688<p>
8689Change the text in the Assertion/note column in the row for "<tt>X u</tt>;"
8690as follows:
8691</p>
8692
8693<blockquote>
8694post: <tt>u.<del>size() == 0</del><ins>empty() == true</ins></tt>
8695</blockquote>
8696</li>
8697
8698<li>
8699<p>
8700Change the text in the Assertion/note column in the row for "<tt>X();</tt>"
8701as follows:
8702</p>
8703
8704<blockquote>
8705<tt>X().<del>size() == 0</del><ins>empty() == true</ins></tt>
8706</blockquote>
8707</li>
8708
8709<li>
8710<p>
8711Change the text in the Operational Semantics column in the row for
8712"<tt>a == b</tt>" as follows:
8713</p>
8714<blockquote>
8715<tt>==</tt> is an equivalence relation.
8716<tt><del>a.size()</del><ins>distance(a.begin(), a.end())</ins> ==
8717   <del>b.size()</del><ins>distance(b.begin(), b.end())</ins> &amp;&amp;
8718equal(a.begin(), a.end(), b.begin())</tt>
8719</blockquote>
8720</li>
8721
8722<li>
8723<p>
8724Change the text in the Operational Semantics column in the row for
8725"<tt>a.size()</tt>" as follows:
8726</p>
8727
8728<blockquote>
8729<tt><del>a.end() - a.begin()</del><ins>distance(a.begin(), a.end())</ins></tt>
8730</blockquote>
8731</li>
8732
8733<li>
8734<p>
8735Change the text in the Operational Semantics column in the row for
8736"<tt>a.max_size()</tt>" as follows:
8737</p>
8738
8739<blockquote>
8740<tt><del>size()</del><ins>distance(begin(), end())</ins></tt> of the largest
8741possible container
8742</blockquote>
8743</li>
8744
8745<li>
8746<p>
8747Change the text in the Operational Semantics column in the row for
8748"<tt>a.empty()</tt>" as follows:
8749</p>
8750
8751<blockquote>
8752<tt><del>a.size() == 0</del><ins>a.begin() == a.end()</ins></tt>
8753</blockquote>
8754</li>
8755</ol>
8756</li>
8757
8758<li>
8759<p>
8760In 23.2.1 [container.requirements.general] change Table 82 -- Allocator-aware container requirements as indicated:
8761</p>
8762
8763<ol type="a">
8764<li>
8765<p>
8766Change the text in the Assertion/note column in the row for "<tt>X() /
8767X u;</tt>" as follows:
8768</p>
8769
8770<blockquote>
8771<i>Requires:</i> <tt>A</tt> is <tt>DefaultConstructible</tt> post: <tt><del>u.size() ==
87720</del><ins>u.empty() == true</ins></tt>, <tt>get_allocator() == A()</tt>
8773</blockquote>
8774</li>
8775
8776<li>
8777<p>
8778Change the text in the Assertion/note column in the row for "<tt>X(m) /
8779X u(m);</tt>" as follows:
8780</p>
8781
8782<blockquote>
8783post: <tt><del>u.size() == 0</del><ins>u.empty() == true</ins>,
8784get_allocator() == m</tt>
8785</blockquote>
8786</li>
8787</ol>
8788</li>
8789
8790<li>
8791<p>
8792In 23.2.3 [sequence.reqmts] change Table 83 -- Sequence container requirements as indicated:
8793</p>
8794
8795<ol type="a">
8796<li>
8797<p>
8798Change the text in the Assertion/note column in the row for "<tt>X(n,
8799t) / X a(n, t)</tt>" as follows:
8800</p>
8801
8802<blockquote>
8803post: <tt><del>size()</del><ins>distance(begin(), end())</ins> == n [..]</tt>
8804</blockquote>
8805</li>
8806
8807<li>
8808<p>
8809Change the text in the Assertion/note column in the row for "<tt>X(i,
8810j) / X a(i, j)</tt>" as follows:
8811</p>
8812
8813<blockquote>
8814[..] post: <del><tt>size() ==</tt> distance between <tt>i</tt> and
8815<tt>j</tt></del><ins><tt>distance(begin(), end()) == distance(i, j)</tt></ins> [..]
8816</blockquote>
8817</li>
8818
8819<li>
8820<p>
8821Change the text in the Assertion/note column in the row for
8822"<tt>a.clear()</tt>" as follows:
8823</p>
8824<blockquote>
8825<tt><ins>a.</ins>erase(<ins>a.</ins>begin(), <ins>a.</ins>end())</tt> post:
8826<tt><del>size() == 0</del><ins>a.empty() == true</ins></tt>
8827</blockquote>
8828</li>
8829</ol>
8830</li>
8831
8832<li>
8833<p>
8834In 23.2.4 [associative.reqmts] change Table 85 -- Associative container requirements as indicated:
8835</p>
8836
8837<p><i>[
8838Not every occurrence of <tt>size()</tt> was replaced, because all current
8839associative containers
8840have a <tt>size</tt>. The following changes ensure consistency regarding the
8841semantics of "<tt>erase</tt>"
8842for all tables and adds some missing objects
8843]</i></p>
8844
8845
8846<ol type="a">
8847<li>
8848<p>
8849Change the text in the Complexity column in the row for
8850"<tt>a.insert(i, j)</tt>" as follows:
8851</p>
8852<blockquote>
8853<tt>N log(<ins>a.</ins>size() + N)</tt> <del>(<tt>N</tt> is the distance from <tt>i</tt> to
8854<tt>j</tt>)</del><ins> where <tt>N == distance(i, j)</tt></ins>
8855</blockquote>
8856</li>
8857
8858<li>
8859<p>
8860Change the text in the Complexity column in the row for
8861"<tt>a.erase(k)</tt>" as follows:
8862</p>
8863<blockquote>
8864<tt>log(<ins>a.</ins>size()) + <ins>a.</ins>count(k)</tt>
8865</blockquote>
8866</li>
8867
8868<li>
8869<p>
8870Change the text in the Complexity column in the row for
8871"<tt>a.erase(q1, q2)</tt>" as follows:
8872</p>
8873
8874<blockquote>
8875<tt>log(<ins>a.</ins>size()) + N</tt> where <tt>N</tt> <del>is the distance from <tt>q1</tt>
8876to <tt>q2</tt></del>
8877   <ins><tt>== distance(q1, q2)</tt></ins>.
8878</blockquote>
8879</li>
8880
8881<li>
8882<p>
8883Change the text in the Assertion/note column in the row for
8884"<tt>a.clear()</tt>" as follows:
8885</p>
8886
8887<blockquote>
8888<tt><ins>a.</ins>erase(a.begin(),a.end())</tt> post: <tt><del>size() ==
88890</del><ins>a.empty() == true</ins></tt>
8890</blockquote>
8891</li>
8892
8893<li>
8894<p>
8895Change the text in the Complexity column in the row for "<tt>a.clear()</tt>"
8896as follows:
8897</p>
8898
8899<blockquote>
8900linear in <tt><ins>a.</ins>size()</tt>
8901</blockquote>
8902</li>
8903
8904<li>
8905<p>
8906Change the text in the Complexity column in the row for
8907"<tt>a.count(k)</tt>" as follows:
8908</p>
8909
8910<blockquote>
8911<tt>log(<ins>a.</ins>size()) + <ins>a.</ins>count(k)</tt>
8912</blockquote>
8913</li>
8914</ol>
8915</li>
8916
8917<li>
8918<p>
8919In 23.2.5 [unord.req] change Table 87 -- Unordered associative container requirements as indicated:
8920</p>
8921<p><i>[
8922The same rational as for Table 85 applies here
8923]</i></p>
8924
8925
8926<ol type="a">
8927<li>
8928<p>
8929Change the text in the Assertion/note column in the row for
8930"<tt>a.clear()</tt>" as follows:
8931</p>
8932
8933<blockquote>
8934[..] Post: <tt>a.<del>size() == 0</del><ins>empty() == true</ins></tt>
8935</blockquote>
8936</li>
8937</ol>
8938</li>
8939</ol>
8940
8941
8942</blockquote>
8943
8944
8945
8946
8947
8948<hr>
8949<h3><a name="865"></a>865. More algorithms that throw away information</h3>
8950<p><b>Section:</b> 25.3.6 [alg.fill], 25.3.7 [alg.generate] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
8951 <b>Submitter:</b> Daniel Kr�gler <b>Opened:</b> 2008-07-13  <b>Last modified:</b> 2009-10-23</p>
8952<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
8953<p><b>Discussion:</b></p>
8954<p>
8955In regard to library defect <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#488">488</a> I found some more algorithms which
8956unnecessarily throw away information. These are typically algorithms,
8957which sequentially write into an <tt>OutputIterator</tt>, but do not return the
8958final value of this output iterator. These cases are:
8959</p>
8960
8961<ol>
8962<li>
8963<pre>template&lt;class OutputIterator, class Size, class T&gt;
8964void fill_n(OutputIterator first, Size n, const T&amp; value);</pre></li>
8965
8966<li>
8967<pre>template&lt;class OutputIterator, class Size, class Generator&gt;
8968void generate_n(OutputIterator first, Size n, Generator gen);</pre></li>
8969</ol>
8970<p>
8971In both cases the minimum requirements on the iterator are
8972<tt>OutputIterator</tt>, which means according to the requirements of
897324.2.2 [output.iterators]/2 that only single-pass iterations are guaranteed.
8974So, if users of <tt>fill_n</tt> and <tt>generate_n</tt> have *only* an <tt>OutputIterator</tt>
8975available, they have no chance to continue pushing further values
8976into it, which seems to be a severe limitation to me.
8977</p>
8978
8979<p><i>[
8980Post Summit Daniel "conceptualized" the wording.
8981]</i></p>
8982
8983
8984<p><i>[
8985Batavia (2009-05):
8986]</i></p>
8987
8988<blockquote>
8989<p>
8990Alisdair likes the idea, but has concerns about the specific wording
8991about the returns clauses.
8992</p>
8993<p>
8994Alan notes this is a feature request.
8995</p>
8996<p>
8997Bill notes we have made similar changes to other algorithms.
8998</p>
8999<p>
9000Move to Open.
9001</p>
9002</blockquote>
9003
9004<p><i>[
90052009-07 Frankfurt
9006]</i></p>
9007
9008
9009<blockquote>
9010We have a consensus for moving forward on this issue, but Daniel needs
9011to deconceptify it.
9012</blockquote>
9013
9014<p><i>[
90152009-07-25 Daniel provided non-concepts wording.
9016]</i></p>
9017
9018
9019<p><i>[
90202009-10 Santa Cruz:
9021]</i></p>
9022
9023
9024<blockquote>
9025Moved to Ready.
9026</blockquote>
9027
9028
9029
9030<p><b>Proposed resolution:</b></p>
9031
9032<ol>
9033<li>
9034<p>
9035Replace the current declaration of <tt>fill_n</tt> in 25 [algorithms]/2, header
9036<tt>&lt;algorithm&gt;</tt> synopsis and in 25.3.6 [alg.fill] by
9037</p>
9038
9039<blockquote><pre>template&lt;class OutputIterator, class Size, class T&gt;
9040  <del>void</del><ins>OutputIterator</ins> fill_n(OutputIterator first, Size n, const T&amp; value);
9041</pre></blockquote>
9042
9043<p>
9044Just after the effects clause add a new returns clause saying:
9045</p>
9046
9047<blockquote>
9048<ins><i>Returns:</i> For <tt>fill_n</tt> and positive <tt>n</tt>, returns <tt>first + n</tt>. Otherwise
9049returns <tt>first</tt> for <tt>fill_n</tt>.</ins>
9050</blockquote>
9051</li>
9052
9053<li>
9054<p>
9055Replace the current declaration of <tt>generate_n</tt> in 25 [algorithms]/2,
9056header <tt>&lt;algorithm&gt;</tt> synopsis and in 25.3.7 [alg.generate] by
9057</p>
9058
9059<blockquote><pre>template&lt;class OutputIterator, class Size, class Generator&gt;
9060  <del>void</del><ins>OutputIterator</ins> generate_n(OutputIterator first, Size n, Generator gen);
9061</pre></blockquote>
9062
9063<p>
9064Just after the effects clause add a new returns clause saying:
9065</p>
9066
9067<blockquote>
9068<ins>For <tt>generate_n</tt> and positive <tt>n</tt>, returns <tt>first + n</tt>. Otherwise
9069returns <tt>first</tt> for <tt>generate_n</tt>.</ins>
9070</blockquote>
9071</li>
9072</ol>
9073
9074
9075
9076
9077
9078
9079
9080<hr>
9081<h3><a name="868"></a>868. default construction and value-initialization</h3>
9082<p><b>Section:</b> 23 [containers] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
9083 <b>Submitter:</b> Alberto Ganesh Barbati <b>Opened:</b> 2008-07-22  <b>Last modified:</b> 2009-10-20</p>
9084<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#containers">active issues</a> in [containers].</p>
9085<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#containers">issues</a> in [containers].</p>
9086<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
9087<p><b>Discussion:</b></p>
9088<p>
9089The term "default constructed" is often used in wording that predates
9090the introduction of the concept of value-initialization. In a few such
9091places the concept of value-initialization is more correct than the
9092current wording (for example when the type involved can be a built-in)
9093so a replacement is in order. Two of such places are already covered by
9094issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#867">867</a>. This issue deliberately addresses the hopefully
9095non-controversial changes in the attempt of being approved more quickly.
9096A few other occurrences (for example in <tt>std::tuple</tt>,
9097<tt>std::reverse_iterator</tt> and <tt>std::move_iterator</tt>) are left to separate
9098issues. For <tt>std::reverse_iterator</tt>, see also issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#408">408</a>. This issue is
9099related with issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#724">724</a>.
9100</p>
9101
9102<p><i>[
9103San Francisco:
9104]</i></p>
9105
9106
9107<blockquote>
9108<p>
9109The list provided in the proposed resolution is not complete. James
9110Dennett will review the library and provide a complete list and will
9111double-check the vocabulary.
9112</p>
9113<p>
9114This issue relates to Issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#886">886</a> tuple construction
9115</p>
9116</blockquote>
9117
9118<p><i>[
91192009-07 Frankfurt
9120]</i></p>
9121
9122
9123<blockquote>
9124<p>
9125The proposed resolution is incomplete.
9126</p>
9127<p>
9128Move to Tentatively NAD Future. Howard will contact Ganesh for wording.
9129If wording is forthcoming, Howard will move it back to Review.
9130</p>
9131</blockquote>
9132
9133<p><i>[
91342009-07-18 Ganesh updated the proposed wording.
9135]</i></p>
9136
9137
9138<blockquote>
9139<p>
9140Howard:  Moved back to Review.  Note that 20.2.1 [utility.arg.requirements]
9141refers to a section that is not in the current working paper, but does refer to
9142a section that we expect to reappear after the de-concepts merge.  This was a
9143point of confusion we did not recognize when we reviewed this issue in Frankfurt.
9144</p>
9145<p>
9146Howard:  Ganesh also includes a survey of places in the WP surveyed for changes
9147of this nature and purposefully <em>not</em> treated:
9148</p>
9149
9150<blockquote>
9151<p>
9152Places where changes are <u>not</u> being
9153proposed
9154</p>
9155<p>
9156In the following paragraphs, we are not proposing changes because
9157it's not clear whether we actually prefer value-initialization over
9158default-initialization (now partially covered by <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1012">1012</a>):
9159</p>
9160<ul>
9161    <li><p>20.8.14.2.1 [unique.ptr.single.ctor] para 3 e 7</p></li>
9162    <li><p>24.5.1.3.1 [reverse.iter.cons] para 1</p></li>
9163    <li><p>24.5.3.3.1 [move.iter.op.const] para 1</p></li>
9164</ul>
9165<p>In the following paragraphs, the expression "default
9166constructed" need not be changed, because the relevant type does
9167not depend on a template parameter and has a user-provided
9168constructor:</p>
9169<ul>
9170    <li><p> [func.referenceclosure.invoke] para 12, type:
9171    reference_closure</p></li>
9172    <li><p>30.3.1.2 [thread.thread.constr] para 30, type: thread</p></li>
9173    <li><p>30.3.1.5 [thread.thread.member] para 52, type: thread_id</p></li>
9174    <li><p>30.3.2 [thread.thread.this], para 1, type: thread_id</p></li>
9175</ul>
9176</blockquote>
9177
9178</blockquote>
9179
9180<p><i>[
91812009-08-18 Daniel adds:
9182]</i></p>
9183
9184
9185<blockquote>
9186<p>
9187I have no objections against the currently suggested changes, but I
9188also cross-checked
9189with the list regarding intentionally excluded changes, and from this
9190I miss the discussion
9191of
9192</p>
9193
9194<ol>
9195<li>
9196<p>
919721.4.1 [string.require]/2:
9198</p>
9199
9200<blockquote>
9201"[..] The <tt>Allocator</tt> object used shall be a copy of the <tt>Allocator&gt;</tt>
9202object passed to the <tt>basic_string</tt> object's
9203constructor or, if the constructor does not take an <tt>Allocator</tt>
9204argument, a copy of a default-constructed
9205<tt>Allocator</tt> object."
9206</blockquote>
9207</li>
9208
9209<li>
9210<p>
9211<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2723.pdf">N2723</a>,
9212X [rand.req.eng], Table 109, expression "<tt>T()</tt>":
9213</p>
9214<blockquote>
9215Pre-/post-condition: "Creates an engine with the same initial state as
9216all other default-constructed engines of type <tt>X</tt>."
9217</blockquote>
9218
9219<p>
9220as well as in 26.5.5 [rand.predef]/1-9 (<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2914.pdf">N2914</a>), 26.5.7.1 [rand.util.seedseq]/3, 27.7.1.1.1 [istream.cons]/3, 27.7.2.2 [ostream.cons]/9 (<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2914.pdf">N2914</a>), 28.13 [re.grammar]/2, 30.3.1.4 [thread.thread.assign]/1 (<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2914.pdf">N2914</a>),
9221</p>
9222<p><i>[
9223Candidates for the "the expression "default constructed" need not be
9224changed" list
9225]</i></p>
9226
9227
9228<p>
9229I'm fine, if these would be added to the intentionally exclusion list,
9230but mentioning them makes it
9231easier for other potential reviewers to decide on the relevance or
9232not-relevance of them for this issue.
9233</p>
9234</li>
9235
9236<li>
9237<p>
9238I suggest to remove the reference of  [func.referenceclosure.invoke]
9239in the "it's not clear" list, because
9240this component does no longer exist.
9241</p>
9242</li>
9243
9244<li>
9245<p>
9246I also suggest to add a short comment that all paragraphs in the
9247resolution whether they refer to <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2723.pdf">N2723</a> or to <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2914.pdf">N2914</a> numbering, because e.g. "Change 23.3.2.1 [deque.cons] para 5" is an <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2723.pdf">N2723</a> coordinate, while "Change 23.3.2.2 [deque.capacity] para 1" is an <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2914.pdf">N2914</a> coordinate. Even better would be to use one default document
9248for the numbering (probably <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2914.pdf">N2914</a>) and mention special cases (e.g. "Change 20.2.1 [utility.arg.requirements] para 2" as referring to <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2723.pdf">N2723</a> numbering).
9249</p>
9250</li>
9251</ol>
9252
9253</blockquote>
9254
9255<p><i>[
92562009-08-18 Alisdair adds:
9257]</i></p>
9258
9259
9260<blockquote>
9261<p>
9262I strongly believe the term "default constructed" should not appear in
9263the library clauses unless we very clearly define a meaning for it, and
9264I am not sure what that would be.
9265</p>
9266
9267<p>
9268In those cases where we do not want to replace "default constructed"
9269with "vale initialized" we should be using "default initialized".  If we
9270have a term that could mean either, we reduce portability of programs.
9271</p>
9272
9273<p>
9274I have not done an exhaustive review to clarify if that is a vendor
9275freedom we have reason to support (e.g. value-init in debug,
9276default-init in release) so I may yet be convinced that LWG has reason
9277to define this new term of art, but generally C++ initialization is
9278confusing enough without supporting further ill-defined terms.
9279</p>
9280</blockquote>
9281
9282<p><i>[
92832009-10 Santa Cruz:
9284]</i></p>
9285
9286
9287<blockquote>
9288Move to Ready.
9289</blockquote>
9290
9291
9292
9293<p><b>Proposed resolution:</b></p>
9294<p>
9295Change 20.2.1 [utility.arg.requirements] para 2:
9296</p>
9297
9298<blockquote>
9299In general, a default constructor is
9300not required. Certain container class member function signatures
9301specify <del>the default constructor</del><ins>T()</ins>
9302as a default argument. T() shall be a well-defined expression (8.5)
9303if one of those signatures is called using the default argument
9304(8.3.6).
9305</blockquote>
9306
9307<p>
9308Change 23.3.2.1 [deque.cons] para 5:
9309</p>
9310
9311<blockquote>
9312<i>Effects:</i> Constructs a deque with n
9313<del>default constructed</del><ins>value-initialized</ins>
9314elements. 
9315</blockquote>
9316
9317<p>
9318Change 23.3.2.2 [deque.capacity] para 1:
9319</p>
9320
9321<blockquote>
9322<i>Effects:</i> If sz &lt; size(), equivalent
9323to erase(begin() + sz, end());. If size() &lt; sz, appends sz -
9324size() <del>default
9325constructed</del><ins>value-initialized</ins>
9326elements to the sequence.
9327</blockquote>
9328
9329<p>
9330Change 23.3.3.1 [forwardlist.cons] para 5:
9331</p>
9332
9333<blockquote>
9334<i>Effects:</i> Constructs a forward_list object with n <del>default
9335constructed</del><ins>value-initialized</ins>
9336elements.
9337</blockquote>
9338
9339<p>
9340Change 23.3.3.4 [forwardlist.modifiers] para 21:
9341</p>
9342
9343<blockquote>
9344<i>Effects:</i> [...] For the first signature
9345the inserted elements are <del>default
9346constructed</del><ins>value-initialized</ins>,
9347and for the second signature they are copies of c.
9348</blockquote>
9349
9350<p>
9351Change 23.3.4.1 [list.cons] para 5:
9352</p>
9353
9354<blockquote>
9355<i>Effects:</i> Constructs a list with n <del>default
9356constructed</del><ins>value-initialized</ins>
9357elements. 
9358</blockquote>
9359
9360<p>
9361Change 23.3.4.2 [list.capacity] para 15:
9362</p>
9363
9364<blockquote>
9365<i>Effects:</i> If sz &lt; size(), equivalent
9366to list&lt;T&gt;::iterator it = begin(); advance(it, sz); erase(it,
9367end());. If size() &lt; sz, appends sz - size() <del>default
9368constructed</del><ins>value-initialized</ins>
9369elements to the sequence.
9370</blockquote>
9371
9372<p>
9373Change 23.3.6.1 [vector.cons] para 3:
9374</p>
9375
9376<blockquote>
9377<i>Effects:</i> Constructs a vector with n
9378<del>default constructed</del><ins>value-initialized</ins>
9379elements. 
9380</blockquote>
9381
9382<p>
9383Change 23.3.6.2 [vector.capacity] para 24:
9384</p>
9385
9386<blockquote>
9387<i>Effects:</i> If sz &lt; size(), equivalent
9388to erase(begin() + sz, end());. If size() &lt; sz, appends sz -
9389size() <del>default
9390constructed</del><ins>value-initialized</ins>
9391elements to the sequence.
9392</blockquote>
9393
9394
9395
9396
9397
9398
9399<hr>
9400<h3><a name="870"></a>870. Do unordered containers not support function pointers for predicate/hasher?</h3>
9401<p><b>Section:</b> 23.2.5 [unord.req] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
9402 <b>Submitter:</b> Daniel Kr�gler <b>Opened:</b> 2008-08-17  <b>Last modified:</b> 2009-10-20</p>
9403<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#unord.req">active issues</a> in [unord.req].</p>
9404<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#unord.req">issues</a> in [unord.req].</p>
9405<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
9406<p><b>Discussion:</b></p>
9407<p>
9408Good ol' associative containers allow both function pointers and
9409function objects as feasible
9410comparators, as described in 23.2.4 [associative.reqmts]/2:
9411</p>
9412
9413<blockquote>
9414Each associative container is parameterized on <tt>Key</tt> and an ordering
9415relation <tt>Compare</tt> that
9416induces a strict weak ordering (25.3) on elements of Key. [..]. The
9417object of type <tt>Compare</tt> is
9418called the comparison object of a container. This comparison object
9419may be a pointer to
9420function or an object of a type with an appropriate function call operator.[..]
9421</blockquote>
9422
9423<p>
9424The corresponding wording for unordered containers is not so clear,
9425but I read it to disallow
9426function pointers for the hasher and I miss a clear statement for the
9427equality predicate, see
942823.2.5 [unord.req]/3+4+5:
9429</p>
9430
9431<blockquote>
9432<p>
9433Each unordered associative container is parameterized by <tt>Key</tt>, by a
9434function object <tt>Hash</tt> that
9435acts as a hash function for values of type <tt>Key</tt>, and by a binary
9436predicate <tt>Pred</tt> that induces an
9437equivalence relation on values of type <tt>Key</tt>.[..]
9438</p>
9439<p>
9440A hash function is a function object that takes a single argument of
9441type <tt>Key</tt> and returns a
9442value of type <tt>std::size_t</tt>.
9443</p>
9444<p>
9445Two values <tt>k1</tt> and <tt>k2</tt> of type <tt>Key</tt> are considered equal if the
9446container's equality function object
9447returns <tt>true</tt> when passed those values.[..]
9448</p>
9449</blockquote>
9450
9451<p>
9452and table 97 says in the column "assertion...post-condition" for the
9453expression X::hasher:
9454</p>
9455
9456<blockquote>
9457<tt>Hash</tt> shall be a unary function object type such that the expression
9458<tt>hf(k)</tt> has type <tt>std::size_t</tt>.
9459</blockquote>
9460
9461<p>
9462Note that 20.7 [function.objects]/1 defines as "Function objects are
9463objects with an <tt>operator()</tt> defined.[..]"
9464</p>
9465<p>
9466Does this restriction exist by design or is it an oversight? If an
9467oversight, I suggest that to apply
9468the following
9469</p>
9470
9471<p><i>[
94722009-07-28 Reopened by Alisdair.  No longer solved by concepts.
9473]</i></p>
9474
9475
9476<p><i>[
94772009-10 Santa Cruz:
9478]</i></p>
9479
9480
9481<blockquote>
9482Ask Daniel to provide proposed wording that: makes it explicit that
9483function pointers are function objects at the beginning of 20.7 [function.objects]; fixes the "requirements" for typedefs in
948420.7.5 [refwrap] to instead state that the function objects
9485defined in that clause have these typedefs, but not that these typedefs
9486are requirements on function objects; remove the wording that explicitly
9487calls out that associative container comparators may be function
9488pointers.
9489</blockquote>
9490
9491
9492
9493<p><b>Proposed resolution:</b></p>
9494<p>
9495In 23.2.5 [unord.req]/3, just after the second sentence which is written as
9496</p>
9497
9498<blockquote>
9499Additionally, <tt>unordered_map</tt> and <tt>unordered_multimap</tt> associate an
9500arbitrary mapped type <tt>T</tt> with the <tt>Key</tt>.
9501</blockquote>
9502
9503<p>
9504add one further sentence:
9505</p>
9506
9507<blockquote>
9508Both <tt>Hash</tt> and <tt>Pred</tt> may be pointers to function or objects of a type
9509with an appropriate function call operator.
9510</blockquote>
9511
9512<p>
9513[Note1: Since the detailed requirements for <tt>Pred</tt> and <tt>Hash</tt> are given in
9514p.4 and p.5, it an alternative resolution
9515would be to insert a new paragraph just after p.5, which contains the
9516above proposed sentence]
9517</p>
9518<p>
9519[Note2: I do not propose a change of above quoted element in table 97,
9520because the mis-usage of the
9521notion of "function object" seems already present in the standard at
9522several places, even if it includes
9523function pointers, see e.g. 25 [algorithms]/7. The important point is
9524that in those places a statement is
9525given that the actually used symbol, like "Predicate" applies for
9526function pointers as well]
9527</p>
9528
9529
9530<p><b>Rationale:</b></p>
9531<p><i>[
9532San Francisco:
9533]</i></p>
9534
9535
9536<blockquote>
9537This is fixed by
9538<a href="" ref="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2776.pdf">N2776</a>.
9539</blockquote>
9540
9541
9542
9543
9544
9545
9546<hr>
9547<h3><a name="871"></a>871. Iota's requirements on T are too strong</h3>
9548<p><b>Section:</b> 26.7.5 [numeric.iota] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
9549 <b>Submitter:</b> Daniel Kr�gler <b>Opened:</b> 2008-08-20  <b>Last modified:</b> 2009-10-22</p>
9550<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
9551<p><b>Discussion:</b></p>
9552<p>
9553According to the recent WP
9554<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2691.pdf">N2691</a>,
955526.7.5 [numeric.iota]/1, the requires clause
9556of <tt>std::iota</tt> says:
9557</p>
9558
9559<blockquote>
9560<tt>T</tt> shall meet the requirements of <tt>CopyConstructible</tt> and <tt>Assignable</tt> types, and
9561shall be convertible to <tt>ForwardIterator</tt>'s value type.[..]
9562</blockquote>
9563
9564<p>
9565Neither <tt>CopyConstructible</tt> nor <tt>Assignable</tt> is needed, instead <tt>MoveConstructible</tt>
9566seems to be the correct choice. I guess the current wording resulted as an
9567artifact from comparing it with similar numerical algorithms like <tt>accumulate</tt>.
9568</p>
9569
9570<p>
9571Note: If this function will be conceptualized, the here proposed
9572<tt>MoveConstructible</tt>
9573requirement can be removed, because this is an implied requirement of
9574function arguments, see
9575<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2710.pdf">N2710</a>/[temp.req.impl]/3, last bullet.
9576</p>
9577
9578<p><i>[
9579post San Francisco:
9580]</i></p>
9581
9582
9583<blockquote>
9584Issue pulled by author prior to review.
9585</blockquote>
9586
9587<p><i>[
95882009-07-30 Daniel reopened:
9589]</i></p>
9590
9591
9592<blockquote>
9593with the absence of concepts, this issue (closed) is valid again and I
9594suggest to reopen it.
9595I also revised by proposed resolution based on N2723 wording:
9596</blockquote>
9597
9598<p><i>[
95992009-10 Santa Cruz:
9600]</i></p>
9601
9602
9603<blockquote>
9604Change 'convertible' to 'assignable', Move To Ready.
9605</blockquote>
9606
9607
9608
9609<p><b>Proposed resolution:</b></p>
9610<p>
9611Change the first sentence of 26.7.5 [numeric.iota]/1:
9612</p>
9613
9614<blockquote>
9615<i>Requires:</i> <tt>T</tt> shall <del>meet the requirements of <tt>CopyConstructible</tt> and
9616<tt>Assignable</tt> types, and shall</del> be
9617assignable to <tt>ForwardIterator</tt>'s value type. [..]
9618</blockquote>
9619
9620
9621
9622
9623
9624
9625
9626
9627<hr>
9628<h3><a name="872"></a>872. <tt>move_iterator::operator[]</tt> has wrong return type</h3>
9629<p><b>Section:</b> 24.5.3.3.12 [move.iter.op.index] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
9630 <b>Submitter:</b> Doug Gregor <b>Opened:</b> 2008-08-21  <b>Last modified:</b> 2009-10-23</p>
9631<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
9632<p><b>Discussion:</b></p>
9633<p>
9634<tt>move_iterator</tt>'s <tt>operator[]</tt> is declared as:
9635</p>
9636
9637<blockquote><pre>reference operator[](difference_type n) const;
9638</pre></blockquote>
9639
9640<p>
9641This has the same problem that <tt>reverse_iterator</tt>'s <tt>operator[]</tt> used to
9642have: if the underlying iterator's <tt>operator[]</tt> returns a proxy, the
9643implicit conversion to <tt>value_type&amp;&amp;</tt> could end up referencing a temporary
9644that has already been destroyed. This is essentially the same issue that
9645we dealt with for <tt>reverse_iterator</tt> in DR <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#386">386</a>.
9646</p>
9647
9648<p><i>[
96492009-07-28 Reopened by Alisdair.  No longer solved by concepts.
9650]</i></p>
9651
9652
9653<p><i>[
96542009-08-15 Howard adds:
9655]</i></p>
9656
9657
9658<blockquote>
9659I recommend closing this as  a duplicate of <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1051">1051</a> which addresses
9660this issue for both <tt>move_iterator</tt> and <tt>reverse_iterator</tt>.
9661</blockquote>
9662
9663<p><i>[
96642009-10 Santa Cruz:
9665]</i></p>
9666
9667
9668<blockquote>
9669Move to Ready. Note that if <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1051">1051</a> is reopened, it may yield a
9670better resolution, but <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1051">1051</a> is currently marked NAD.
9671</blockquote>
9672
9673
9674
9675<p><b>Proposed resolution:</b></p>
9676<p>
9677In 24.5.3.1 [move.iterator] and 24.5.3.3.12 [move.iter.op.index], change the declaration of
9678<tt>move_iterator</tt>'s <tt>operator[]</tt> to:
9679</p>
9680
9681<blockquote><pre><del>reference</del> <ins><i>unspecified</i></ins> operator[](difference_type n) const;
9682</pre></blockquote>
9683
9684
9685
9686<p><b>Rationale:</b></p>
9687<p><i>[
9688San Francisco:
9689]</i></p>
9690
9691
9692<blockquote>
9693NAD Editorial, see
9694<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2777.pdf">N2777</a>.
9695</blockquote>
9696
9697
9698
9699
9700<hr>
9701<h3><a name="885"></a>885. pair assignment</h3>
9702<p><b>Section:</b> 20.3.4 [pairs] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
9703 <b>Submitter:</b> Alisdair Meredith <b>Opened:</b> 2008-09-15  <b>Last modified:</b> 2009-07-17</p>
9704<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#pairs">active issues</a> in [pairs].</p>
9705<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#pairs">issues</a> in [pairs].</p>
9706<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
9707<p><b>Discussion:</b></p>
9708<blockquote><pre>20.2.3 pairs
9709Missing assignemnt operator:
9710template&lt;class U , class V&gt;
9711  requires CopyAssignable&lt;T1, U&gt; &amp;&amp; CopyAssignable&lt;T2, V&gt;
9712    pair&amp; operator=(pair&lt;U , V&gt; const &amp; p );
9713</pre></blockquote>
9714
9715<p>
9716Well, that's interesting. This assignment operator isn't in the
9717current working paper, either. Perhaps we deemed it acceptable to
9718build a temporary of type <tt>pair</tt> from <tt>pair&lt;U, V&gt;</tt>, then move-assign
9719from that temporary?
9720</p>
9721<p>
9722It sounds more like an issue waiting to be opened, unless you want to plug
9723it now.  As written we risk moving from lvalues.
9724</p>
9725
9726<p><i>[
9727San Francisco:
9728]</i></p>
9729
9730
9731<blockquote>
9732<p>
9733Would be NAD if better ctors fixed it.
9734</p>
9735<p>
9736Related to <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#811">811</a>.
9737</p>
9738</blockquote>
9739
9740<p><i>[
9741post San Francisco:
9742]</i></p>
9743
9744
9745<blockquote>
9746Possibly NAD Editorial, solved by
9747<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2770.pdf">N2770</a>.
9748</blockquote>
9749
9750<p><i>[
97512009-05-25 Alisdair adds:
9752]</i></p>
9753
9754
9755<blockquote>
9756Issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#885">885</a> was something I reported while reviewing the library concepts
9757documents ahead of San Francisco.  The missing operator was added as part of
9758the paper adopted at that meeting
9759(<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2770.pdf">N2770</a>)
9760and I can confirm this operator is
9761present in the current working paper.  I recommend NAD.
9762</blockquote>
9763
9764<p><i>[
97652009-07 Frankfurt
9766]</i></p>
9767
9768
9769<blockquote>
9770We agree with the intent, but we need to wait for the dust to settle on concepts.
9771</blockquote>
9772
9773
9774
9775<p><b>Proposed resolution:</b></p>
9776<p>
9777</p>
9778
9779
9780
9781
9782
9783<hr>
9784<h3><a name="887"></a>887. issue with condition::wait_...</h3>
9785<p><b>Section:</b> 30.5.1 [thread.condition.condvar] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
9786 <b>Submitter:</b> Lawrence Crowl <b>Opened:</b> 2008-09-15  <b>Last modified:</b> 2009-10-26</p>
9787<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#thread.condition.condvar">active issues</a> in [thread.condition.condvar].</p>
9788<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#thread.condition.condvar">issues</a> in [thread.condition.condvar].</p>
9789<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
9790<p><b>Discussion:</b></p>
9791<p>
9792The Posix/C++ working group has identified an inconsistency between
9793Posix and the C++ working draft in that Posix requires the clock to be
9794identified at creation, whereas C++ permits identifying the clock at the
9795call to wait.  The latter cannot be implemented with the former.
9796</p>
9797
9798<p><i>[
9799San Francisco:
9800]</i></p>
9801
9802
9803<blockquote>
9804<p>
9805Howard recommends NAD with the following explanation:
9806</p>
9807
9808<p>
9809The intent of the current wording is for the <tt>condtion_variable::wait_until</tt>
9810be able to handle user-defined clocks as well as clocks the system knows about.
9811This can be done by providing overloads for the known clocks, and another
9812overload for unknown clocks which synchs to a known clock before waiting.
9813For example:
9814</p>
9815
9816<blockquote><pre>template &lt;class Duration&gt;
9817bool
9818condition_variable::wait_until(unique_lock&lt;mutex&gt;&amp; lock,
9819                               const chrono::time_point&lt;chrono::system_clock, Duration&gt;&amp; abs_time)
9820{
9821    using namespace chrono;
9822    nanoseconds d = __round_up&lt;nanoseconds&gt;(abs_time.time_since_epoch());
9823    __do_timed_wait(lock.mutex()-&gt;native_handle(), time_point&lt;system_clock, nanoseconds&gt;(d));
9824    return system_clock::now() &lt; abs_time;
9825}
9826
9827template &lt;class Clock, class Duration&gt;
9828bool
9829condition_variable::wait_until(unique_lock&lt;mutex&gt;&amp; lock,
9830                               const chrono::time_point&lt;Clock, Duration&gt;&amp; abs_time)
9831{
9832    using namespace chrono;
9833    system_clock::time_point    s_entry = system_clock::now();
9834    typename Clock::time_point  c_entry = Clock::now();
9835    nanoseconds dn = __round_up&lt;nanoseconds&gt;(abs_time.time_since_epoch() -
9836                                              c_entry.time_since_epoch());
9837    __do_timed_wait(lock.mutex()-&gt;native_handle(), s_entry + dn);
9838    return Clock::now() &lt; abs_time;
9839}
9840</pre></blockquote>
9841
9842<p>
9843In the above example, <tt>system_clock</tt> is the only clock which the underlying
9844condition variable knows how to deal with.  One overload just passes that clock
9845through.  The second overload (approximately) converts the unknown clock into
9846a <tt>system_clock  time_point</tt> prior to passing it down to the native
9847condition variable.
9848</p>
9849
9850<p>
9851On Posix systems vendors are free to add implementation defined constructors which
9852take a clock.  That clock can be stored in the condition_variable, and converted
9853to (or not as necessary) as shown above.
9854</p>
9855
9856<p>
9857If an implementation defined constructor takes a clock (for example), then part
9858of the semantics for that implementation defined ctor might include that a
9859<tt>wait_until</tt> using a clock other than the one constructed with results
9860in an error (exceptional condition) instead of a conversion to the stored clock.
9861Such a design is up to the vendor as once an implementation defined ctor is used,
9862the vendor is free to specifiy the behavior of waits and/or notifies however
9863he pleases (when the cv is constructed in an implementation defined manner).
9864</p>
9865</blockquote>
9866
9867<p><i>[
9868Post Summit:
9869]</i></p>
9870
9871
9872<blockquote>
9873<p>
9874"POSIX people will review the proposed NAD resolution at their upcoming NY
9875meeting.
9876</p>
9877
9878<p>
9879See the minutes at: <a href="http://wiki.dinkumware.com/twiki/bin/view/Posix/POSIX-CppBindingWorkingGroupNewYork2009">http://wiki.dinkumware.com/twiki/bin/view/Posix/POSIX-CppBindingWorkingGroupNewYork2009</a>.
9880</p>
9881</blockquote>
9882
9883<p><i>[
98842009-07 Frankfurt
9885]</i></p>
9886
9887
9888<blockquote>
9889Move to NAD.
9890</blockquote>
9891
9892<p><i>[
98932009-07-18 Detlef reopens the issue:
9894]</i></p>
9895
9896
9897<blockquote>
9898<p>
9899On Friday afternoon in Frankfurt is was decided that 887 is NAD.
9900This decision was mainly based on a sample implementation presented
9901by Howard that implemented one clock on top of another.
9902Unfortunately this implementation doesn't work for the probably most
9903important case where a system has a monotonic clock and a real-time
9904clock (or "wall time" clock):
9905</p>
9906<p>
9907If the underlying "system_clock" is a monotonic clock, and
9908the program waits on the real-time clock, and the real-time clock
9909is set forward, the wait will unblock too late.
9910</p>
9911
9912<p>
9913If the underlying "system_clock" is a real-time clock, and the
9914program waits on the monotonic clock, and the real-time clock
9915is set back, the wait again will unblock too late.
9916</p>
9917
9918<p>
9919Sorry that I didn't remember this on Friday, but it was Friday
9920afternoon after a busy week...
9921</p>
9922
9923<p>
9924So as the decision was made on a wrong asumption, I propose to re-open
9925the issue.
9926</p>
9927</blockquote>
9928
9929<p><i>[
99302009-07-26 Howard adds:
9931]</i></p>
9932
9933
9934<blockquote>
9935<p>
9936Detlef correctly argues that <tt>condition_variable::wait_until</tt> could
9937return "too late" in the context of clocks being adjusted during the wait.  I agree
9938with his logic.  But I disagree that this makes this interface unimplementable
9939on POSIX.
9940</p>
9941
9942<p>
9943The POSIX spec also does not guarantee that <tt>pthread_cond_timedwait</tt> does
9944not return "too late" when clocks are readjusted during the wait.  Indeed, the
9945POSIX specification lacks any requirements at all concerning how soon
9946<tt>pthread_cond_timedwait</tt> returns after a time out.  This is evidently a
9947QOI issue by the POSIX standard.  Here is a quote of the most relevant normative
9948text concerning <tt>pthread_cond_timedwait</tt> found
9949<a href="http://www.unix.org/single_unix_specification/">here</a>.
9950</p>
9951
9952<blockquote>
9953The <tt>pthread_cond_timedwait()</tt> function shall be equivalent to
9954<tt>pthread_cond_wait()</tt>, except that an error is returned if the absolute
9955time specified by <tt>abstime</tt> passes (that is, system time equals or exceeds
9956<tt>abstime</tt>) before the condition <tt>cond</tt> is signaled or broadcasted, or if the
9957absolute time specified by <tt>abstime</tt> has already been passed at the time
9958of the call.
9959</blockquote>
9960
9961<p>
9962I.e. the POSIX specification speaks of the error code returned in case of a time
9963out, but not on the timeliness of that return.
9964</p>
9965
9966<p>
9967Might this simply be an oversight, or minor defect in the POSIX specification?
9968</p>
9969
9970<p>
9971I do not believe so.  This same section goes on to say in <em>non-normative</em>
9972text:
9973</p>
9974
9975<blockquote>
9976For cases when the system clock is advanced discontinuously by an
9977operator, it is expected that implementations process any timed wait
9978expiring at an intervening time as if that time had actually occurred.
9979</blockquote>
9980
9981<p>
9982Here is non-normative wording encouraging the implementation to ignore an advancing
9983underlying clock and subsequently causing an early (spurious) return.  There is
9984no wording at all which addresses Detlef's example of a "late return".  With
9985<tt>pthread_cond_timedwait</tt> this would be caused by setting the system clock
9986backwards.  It seems reasonable to assume, based on the wording that is already
9987in the POSIX spec, that again, the discontinuously changed clock would be ignored
9988by <tt>pthread_cond_timedwait</tt>. 
9989</p>
9990
9991<p>
9992A noteworthy difference between <tt>pthread_cond_timedwait</tt> and
9993<tt>condition_variable::wait_until</tt> is that the POSIX spec appears to
9994say that <tt>ETIMEDOUT</tt> should be returned if <tt>pthread_cond_timedwait</tt>
9995returns because of timeout signal, whether or not the system clock was discontinuously
9996advanced during the wait.  In contrast <tt>condition_variable::wait_until</tt>
9997always returns:
9998</p>
9999
10000<blockquote><pre><tt>Clock::now() &lt; abs_time</tt>
10001</pre></blockquote>
10002
10003<p>
10004That is, the C++ spec requires that the clock be rechecked (detecting discontinuous
10005adjustments during the wait) at the time of return.  <tt>condition_variable::wait_until</tt>
10006may indeed return early or late.  But regardless it will return a value
10007reflecting timeout status at the time of return (even if clocks have been adjusted).
10008Of course the clock may be adjusted after the return value is computed but before the client has
10009a chance to read the result of the return.  Thus there are no iron-clad guarantees
10010here.
10011</p>
10012
10013<p>
10014<tt>condition_variable::wait_until</tt> (and <tt>pthread_cond_timedwait</tt>)
10015is little more than a convenience function for making sure
10016<tt>condition_variable::wait</tt> doesn't hang for an unreasonable amount of
10017time (where the client gets to define "unreasonable").  I do not think it
10018is in anyone's interest to try to make it into anything more than that.
10019</p>
10020
10021<p>
10022I maintain that this is a useful and flexible specification in the spirit of
10023C++, and is implementable on POSIX.  The implementation technique described above
10024is a reasonable approach.  There may also be higher quality approaches.  This
10025specification, like the POSIX specification, gives a wide latitude for QOI.
10026</p>
10027
10028<p>
10029I continue to recommend NAD, but would not object to a clarifying note regarding
10030the behavior of <tt>condition_variable::wait_until</tt>.  At the moment, I do
10031not have good wording for such a note, but welcome suggestions.
10032</p>
10033
10034</blockquote>
10035
10036<p><i>[
100372009-09-30: See <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2969.html">N2969</a>.
10038]</i></p>
10039
10040
10041<p><i>[
100422009-10 Santa Cruz:
10043]</i></p>
10044
10045
10046<blockquote>
10047The LWG is in favor of Detlef to supply revision which adopts Option 2 from
10048<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2969.html">N2969</a>
10049but is modified by saying that <tt>system_clock</tt> must be available for <tt>wait_until</tt>.
10050</blockquote>
10051
10052
10053
10054<p><b>Proposed resolution:</b></p>
10055<p>
10056</p>
10057
10058
10059
10060
10061
10062<hr>
10063<h3><a name="889"></a>889. thread::id comparisons</h3>
10064<p><b>Section:</b> 30.3.1.1 [thread.thread.id] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
10065 <b>Submitter:</b> Lawrence Crowl <b>Opened:</b> 2008-09-15  <b>Last modified:</b> 2009-10-22</p>
10066<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#thread.thread.id">issues</a> in [thread.thread.id].</p>
10067<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
10068<p><b>Discussion:</b></p>
10069
10070<p><b>Addresses UK 324</b></p>
10071
10072<p>
10073The <tt>thread::id</tt> type supports the full set of comparison operators.  This
10074is substantially more than is required for the associative containers that
10075justified them.  Please place an issue against the threads library.
10076</p>
10077
10078<p><i>[
10079San Francisco:
10080]</i></p>
10081
10082
10083<blockquote>
10084<p>
10085Would depend on proposed extension to POSIX, or non-standard extension.
10086What about hash? POSIX discussing op. POSIX not known to be considering
10087support needed for hash, op.
10088</p>
10089<p>
10090Group expresses support for putting ids in both unordered and ordered containers.
10091</p>
10092</blockquote>
10093
10094<p><i>[
10095post San Francisco:
10096]</i></p>
10097
10098
10099<blockquote>
10100<p>
10101Howard:  It turns out the current working paper
10102<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2723.pdf">N2723</a>
10103<i>already has</i> <tt>hash&lt;thread::id&gt;</tt>
10104(20.7 [function.objects], 20.7.16 [unord.hash]).  We simply
10105overlooked it in the meeting.  It is a good thing we voted in favor of it
10106(again). :-)
10107</p>
10108<p>
10109Recommend NAD.
10110</p>
10111
10112</blockquote>
10113
10114<p><i>[
10115Post Summit:
10116]</i></p>
10117
10118
10119<blockquote>
10120Recommend to close as NAD. For POSIX, see if we need to add a function to
10121convert <tt>pthread_t</tt> to integer.
10122</blockquote>
10123
10124<p><i>[
10125Post Summit, Alisdair adds:
10126]</i></p>
10127
10128
10129<blockquote>
10130<p>
10131The recommendation for LWG-889/UK-324 is NAD, already specified.
10132</p>
10133<p>
10134It is not clear to me that the specification is complete.
10135</p>
10136<p>
10137In particular, the synopsis of <tt>&lt;functional&gt;</tt> in 20.7 [function.objects] does not mention <tt>hash&lt; thread::id
10138&gt;</tt> nor <tt>hash&lt; error_code &gt;</tt>, although their
10139existence is implied by 20.7.16 [unord.hash], p1.
10140</p>
10141<p>
10142I am fairly uncomfortable putting the declaration for the
10143<tt>thread_id</tt> specialization into <tt>&lt;functional&gt;</tt> as
10144<tt>id</tt> is a nested class inside <tt>std::thread</tt>, so it implies
10145that <tt>&lt;functional&gt;</tt> would require the definition of the
10146<tt>thread</tt> class template in order to forward declared
10147<tt>thread::id</tt> and form this specialization.
10148</p>
10149<p>
10150It seems better to me that the dependency goes the other way around
10151(<tt>&lt;thread&gt;</tt> will more typically make use of
10152<tt>&lt;functional&gt;</tt> than vice-versa) and the
10153<tt>hash&lt;thread::id&gt;</tt> specialization be declared in the
10154<tt>&lt;thread&gt;</tt> header.
10155</p>
10156<p>
10157I think <tt>hash&lt;error_code&gt;</tt> could go into either
10158<tt>&lt;system_error&gt;</tt> or <tt>&lt;functional&gt;</tt> and have no
10159immediate preference either way.  However, it should clearly appear in
10160the synopsis of one of these two.
10161</p>
10162<p>
10163Recommend moving 889 back to open, and tying in a reference to UK-324.
10164</p>
10165</blockquote>
10166
10167<p><i>[
10168Batavia (2009-05):
10169]</i></p>
10170
10171<blockquote>
10172Howard observes that <tt>thread::id</tt> need not be a nested class;
10173it could be a <tt>typedef</tt> for a more visible type.
10174</blockquote>
10175
10176<p><i>[
101772009-05-24 Alisdair adds:
10178]</i></p>
10179
10180<blockquote>
10181I do not believe this is correct.  <tt>thread::id</tt> is explicitly documents as a
10182nested class, rather than as an unspecified typedef analogous to an
10183iterator.  If the intent is that this is not implemented as a nested class
10184(under the as-if freedoms) then this is a novel form of standardese.
10185</blockquote>
10186
10187<p><i>[
101882009-07 Frankfurt
10189]</i></p>
10190
10191
10192<blockquote>
10193Decided we want to move hash specialization for thread_id to the thread
10194header. Alisdair to provide wording.
10195</blockquote>
10196
10197<p><i>[
101982009-07-28 Alisdair provided wording, moved to Review.
10199]</i></p>
10200
10201
10202<p><i>[
102032009-10 Santa Cruz:
10204]</i></p>
10205
10206
10207<blockquote>
10208Add a strike for <tt>hash&lt;thread::id&gt;</tt>. Move to Ready
10209</blockquote>
10210
10211
10212
10213<p><b>Proposed resolution:</b></p>
10214
10215<p>
10216Remove the following prototype from the synopsis in
1021720.7 [function.objects]:
10218</p>
10219
10220<blockquote><pre><del>
10221template &lt;&gt; struct hash&lt;std::thread::id&gt;;
10222</del></pre></blockquote>
10223
10224<p>
10225Add to 30.3 [thread.threads], p1 Header <tt>&lt;thread&gt;</tt> synopsis:
10226</p>
10227
10228<blockquote><pre><ins>template &lt;class T&gt; struct hash;
10229template &lt;&gt; struct hash&lt;thread::id&gt;;</ins>
10230</pre></blockquote>
10231
10232<p>
10233Add template specialization below class definition in 30.3.1.1 [thread.thread.id]
10234</p>
10235
10236<blockquote><pre><ins>template &lt;&gt;
10237struct hash&lt;thread::id&gt; : public unary_function&lt;thread::id, size_t&gt; {
10238   size_t operator()(thread::id val) const;
10239};</ins>
10240</pre></blockquote>
10241
10242<p>
10243Extend note in p2 30.3.1.1 [thread.thread.id] with second sentence:
10244</p>
10245
10246<blockquote>
10247[<i>Note:</i> Relational operators allow <tt>thread::id</tt> objects to be used
10248as keys in associative containers.
10249<ins><tt>hash</tt> template specialization allow <tt>thread::id</tt> objects to be used as keys
10250in unordered containers.</ins>
10251&#8212; <i>end note</i>]
10252</blockquote>
10253
10254<p>
10255Add new paragraph to end of 30.3.1.1 [thread.thread.id]
10256</p>
10257
10258<blockquote><pre><ins>template &lt;&gt; struct hash&lt;thread::id&gt;;</ins>
10259</pre>
10260<blockquote><ins>
10261An explicit specializations of the class template hash (20.7.16 [unord.hash])
10262shall be provided for the values of type <tt>thread::id</tt>
10263suitable for use as keys in unordered associative containers (23.5 [unord]).
10264</ins></blockquote>
10265</blockquote>
10266
10267
10268
10269
10270
10271<hr>
10272<h3><a name="891"></a>891. std::thread, std::call_once issue</h3>
10273<p><b>Section:</b> 30.3.1.2 [thread.thread.constr], 30.4.5.2 [thread.once.callonce] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
10274 <b>Submitter:</b> Peter Dimov <b>Opened:</b> 2008-09-15  <b>Last modified:</b> 2009-10-24</p>
10275<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#thread.thread.constr">active issues</a> in [thread.thread.constr].</p>
10276<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#thread.thread.constr">issues</a> in [thread.thread.constr].</p>
10277<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
10278<p><b>Discussion:</b></p>
10279<p>
10280I notice that the vararg overloads of <tt>std::thread</tt> and <tt>std::call_once</tt>
10281(N2723 30.3.1.2 [thread.thread.constr] and 30.4.5.2 [thread.once.callonce]) are no longer specified in terms of
10282<tt>std::bind</tt>; instead, some of the <tt>std::bind</tt> wording has been inlined into
10283the specification.
10284</p>
10285<p>
10286There are two problems with this.
10287</p>
10288<p>
10289First, the specification (and implementation) in terms of <tt>std::bind</tt> allows, for example:
10290</p>
10291
10292<blockquote><pre>std::thread th( f, 1, std::bind( g ) );
10293</pre></blockquote>
10294
10295<p>
10296which executes <tt>f( 1, g() )</tt> in a thread. This can be useful. The
10297"inlined" formulation changes it to execute <tt>f( 1, bind(g) )</tt> in a thread.
10298</p>
10299<p>
10300Second, assuming that we don't want the above, the specification has copied the wording
10301</p>
10302
10303<blockquote>
10304<tt>INVOKE(func, w1, w2, ..., wN)</tt> (20.6.2) shall be a valid
10305expression for some values <tt>w1, w2, ..., wN</tt>
10306</blockquote>
10307
10308<p>
10309but this is not needed since we know that our argument list is args; it should simply be
10310</p>
10311
10312<blockquote>
10313<tt>INVOKE(func, args...)</tt> (20.6.2) shall be a valid expression
10314</blockquote>
10315
10316<p><i>[
10317Summit:
10318]</i></p>
10319
10320
10321<blockquote>
10322Move to open.
10323</blockquote>
10324
10325<p><i>[
10326Post Summit Anthony provided proposed wording.
10327]</i></p>
10328
10329
10330<p><i>[
103312009-07 Frankfurt
10332]</i></p>
10333
10334
10335<blockquote>
10336Leave Open. Await decision for thread variadic constructor.
10337</blockquote>
10338
10339<p><i>[
103402009-10 Santa Cruz:
10341]</i></p>
10342
10343
10344<blockquote>
10345See proposed wording for <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#929">929</a> for this, for the formulation
10346on how to solve this.  <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#929">929</a> modifies the thread constructor to
10347have "pass by value" behavior with pass by reference efficiency through the use
10348of the <tt>decay</tt> trait.  This same formula would be useful for <tt>call_once</tt>.
10349</blockquote>
10350
10351
10352
10353<p><b>Proposed resolution:</b></p>
10354<p>
10355Change paragraph 4 of 30.3.1.2 [thread.thread.constr] to:
10356</p>
10357
10358<blockquote>
10359<pre>template &lt;class F&gt; explicit thread(F f);
10360template &lt;class F, class ...Args&gt; thread(F&amp;&amp; f, Args&amp;&amp;... args);
10361</pre>
10362<blockquote>
10363-4- <i>Requires:</i> <tt>F</tt> and each <tt>Ti</tt> in <tt>Args</tt>
10364shall be <tt>CopyConstructible</tt> if an lvalue and otherwise
10365<tt>MoveConstructible</tt>. <tt><i>INVOKE</i>(f, <del>w1, w2, ..., wN</del> <ins>args...</ins>)</tt>
10366(20.6.2) shall be a valid expression<del> for some values <i>w1, w2, ...,
10367wN</i>, where <tt>N == sizeof...(Args)</tt></del>.
10368</blockquote>
10369</blockquote>
10370
10371<p>
10372Change paragraph 1 of 30.4.5.2 [thread.once.callonce] to:
10373</p>
10374
10375<blockquote><pre>template&lt;class Callable, class ...Args&gt; 
10376  void call_once(once_flag&amp; flag, Callable func, Args&amp;&amp;... args);
10377</pre>
10378<blockquote>
10379-1- <i>Requires:</i> The template parameters <tt>Callable&gt;</tt> and each
10380<tt>Ti</tt> in <tt>Args</tt> shall be <tt>CopyConstructible</tt> if an
10381lvalue and otherwise <tt>MoveConstructible</tt>. <tt><i>INVOKE</i>(func,
10382<del>w1, w2, ..., wN</del> <ins>args...</ins>)</tt> (20.6.2) shall be a
10383valid expression<del> for some values <i>w1, w2, ..., wN</i>, where
10384<tt>N == sizeof...(Args)</tt></del>.
10385</blockquote>
10386</blockquote>
10387
10388
10389
10390
10391
10392<hr>
10393<h3><a name="893"></a>893. std::mutex issue</h3>
10394<p><b>Section:</b> 30.4.1.1 [thread.mutex.class] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
10395 <b>Submitter:</b> Peter Dimov <b>Opened:</b> 2008-09-15  <b>Last modified:</b> 2009-10-22</p>
10396<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#thread.mutex.class">issues</a> in [thread.mutex.class].</p>
10397<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
10398<p><b>Duplicate of:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#905">905</a></p>
10399<p><b>Discussion:</b></p>
10400<p>
1040130.4.1.1 [thread.mutex.class]/27 (in
10402<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2723.pdf">N2723</a>)
10403says that the behavior is undefined if:
10404</p>
10405<ul>
10406<li>a thread that owns a <tt>mutex</tt> object calls <tt>lock()</tt> or
10407<tt>try_lock()</tt> on that object</li>
10408</ul>
10409<p>
10410I don't believe that this is right. Calling <tt>lock()</tt> or <tt>try_lock()</tt> on a
10411locked <tt>mutex</tt> is well defined in the general case. <tt>try_lock()</tt> is required
10412to fail and return <tt>false</tt>. <tt>lock()</tt> is required to either throw an
10413exception (and is allowed to do so if it detects deadlock) or to block
10414until the <tt>mutex</tt> is free. These general requirements apply regardless of
10415the current owner of the <tt>mutex</tt>; they should apply even if it's owned by
10416the current thread.
10417</p>
10418<p>
10419Making double <tt>lock()</tt> undefined behavior probably can be justified (even
10420though I'd still disagree with the justification), but <tt>try_lock()</tt> on a
10421locked <tt>mutex</tt> must fail.
10422</p>
10423
10424<p><i>[
10425Summit:
10426]</i></p>
10427
10428<blockquote>
10429<p>
10430Move to open. Proposed resolution:
10431</p>
10432<ul>
10433<li>
10434In 30.4.1 [thread.mutex.requirements] paragraph 12, change the error
10435condition for <tt>resource_deadlock_would_occur</tt> to: "if the implementation
10436detects that a deadlock would occur"
10437</li>
10438<li>
10439Strike 30.4.1.1 [thread.mutex.class] paragraph 3 bullet 2 "a thread that owns a mutex object
10440calls <tt>lock()</tt> or <tt>try_lock()</tt> on that object, or"
10441</li>
10442</ul>
10443</blockquote>
10444
10445<p><i>[
104462009-07 Frankfurt
10447]</i></p>
10448
10449
10450<blockquote>
10451Move to Review. Alisdair to provide note.
10452</blockquote>
10453
10454<p><i>[
104552009-07-31 Alisdair provided note.
10456]</i></p>
10457
10458
10459<p><i>[
104602009-10 Santa Cruz:
10461]</i></p>
10462
10463
10464<blockquote>
10465Moved to Ready.
10466</blockquote>
10467
10468
10469
10470<p><b>Proposed resolution:</b></p>
10471<p>
10472In 30.4.1 [thread.mutex.requirements] paragraph 12 change:
10473</p>
10474
10475<blockquote>
10476<ul>
10477<li>...</li>
10478<li>
10479<tt>resource_deadlock_would_occur</tt> -- if the <del>current thread already owns the mutex and is able 
10480to detect it</del> <ins>implementation detects that a deadlock would occur</ins>.
10481</li>
10482<li>...</li>
10483</ul>
10484</blockquote>
10485
10486<p>
10487Strike 30.4.1.1 [thread.mutex.class] paragraph 3 bullet 2:
10488</p>
10489<blockquote>
10490<p>
10491-3- The behavior of a program is undefined if:
10492</p>
10493<ul>
10494<li>...</li>
10495<li>
10496<del>a thread that owns a <tt>mutex</tt> object calls <tt>lock()</tt> or <tt>try_lock()</tt> on that object, or</del>
10497</li>
10498<li>...</li>
10499</ul>
10500</blockquote>
10501
10502<p>
10503Add the following note after p3 30.4.1.1 [thread.mutex.class]
10504</p>
10505
10506<blockquote>
10507[<i>Note:</i> a program may deadlock if the thread that owns a <tt>mutex</tt>
10508object calls <tt>lock()</tt> or <tt>try_lock()</tt> on that object. If the program can
10509detect the deadlock, a <tt>resource_deadlock_would_occur</tt> error condition may
10510be observed. &#8212; <i>end note</i>]
10511</blockquote>
10512
10513
10514
10515
10516
10517
10518<hr>
10519<h3><a name="896"></a>896. Library thread safety issue</h3>
10520<p><b>Section:</b> 20.8.15.2 [util.smartptr.shared] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
10521 <b>Submitter:</b> Hans Boehm <b>Opened:</b> 2008-09-16  <b>Last modified:</b> 2009-10-25</p>
10522<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#util.smartptr.shared">issues</a> in [util.smartptr.shared].</p>
10523<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
10524<p><b>Discussion:</b></p>
10525<p>
10526It is unclear whether <tt>shared_ptr</tt> is thread-safe in the sense that
10527multiple threads may simultaneously copy a <tt>shared_ptr</tt>.  However this
10528is a critical piece of information for the client, and it has significant
10529impact on usability for many applications.  (Detlef Vollman thinks it
10530is currently clear that it is not thread-safe.  Hans Boehm thinks
10531it currently requires thread safety, since the <tt>use_count</tt> is not an
10532explicit field, and constructors and assignment take a const reference
10533to an existing <tt>shared_ptr</tt>.)
10534</p>
10535
10536<p>
10537Pro thread-safety:
10538</p>
10539<p>
10540Many multi-threaded usages are impossible.  A thread-safe version can
10541be used to destroy an object when the last thread drops it, something
10542that is often required, and for which we have no other easy mechanism.
10543</p>
10544<p>
10545Against thread-safety:
10546</p>
10547<p>
10548The thread-safe version is well-known to be far more expensive, even
10549if used by a single thread.  Many applications, including all single-threaded
10550ones, do not care.
10551</p>
10552
10553<p><i>[
10554San Francisco:
10555]</i></p>
10556
10557
10558<blockquote>
10559<p>
10560Beman: this is a complicated issue, and would like to move this to Open
10561and await comment from Peter Dimov; we need very careful and complete
10562rationale for any decision we make; let's go slow
10563</p>
10564<p>
10565Detlef: I think that <tt>shared_ptr</tt> should not be thread-safe.
10566</p>
10567<p>
10568Hans: When you create a thread with a lambda, it in some cases makes it
10569very difficult for the lambda to reference anything in the heap. It's
10570currently ambiguous as to whether you can use a <tt>shared_ptr</tt> to get at an
10571object.
10572</p>
10573<p>
10574Leave in Open. Detlef will submit an alternative proposed resolution
10575that makes <tt>shared_ptr</tt> explicitly unsafe.
10576</p>
10577<p>
10578A third option is to support both threadsafe and non-safe share_ptrs,
10579and to let the programmer decide which behavior they want.
10580</p>
10581
10582<p>
10583Beman:  Peter, do you support the PR?
10584</p>
10585
10586<p>
10587Peter:
10588</p>
10589<blockquote>
10590<p>
10591Yes, I support the proposed resolution, and I certainly oppose any
10592attempts to <tt>make shared_ptr</tt> thread-unsafe.
10593</p>
10594<p>
10595I'd mildly prefer if
10596</p>
10597<blockquote>
10598[<i>Note:</i> This is true in spite of that fact that such functions often
10599modify <tt>use_count()</tt> <i>--end note</i>]
10600</blockquote>
10601<p>
10602is changed to
10603</p>
10604<blockquote>
10605[<i>Note:</i> This is true in spite of that fact that such functions often
10606cause a change in <tt>use_count()</tt> <i>--end note</i>]
10607</blockquote>
10608<p>
10609(or something along these lines) to emphasise that <tt>use_count()</tt> is not,
10610conceptually, a variable, but a return value.
10611</p>
10612</blockquote>
10613
10614</blockquote>
10615
10616<p><i>[
106172009-07 Frankfurt
10618]</i></p>
10619
10620
10621<blockquote>
10622<p>
10623Vote: Do we want one thread-safe shared pointer or two? If two, one
10624would allow concurrent construction and destruction of shared pointers,
10625and one would not be thread-safe. If one, then it would be thread-safe.
10626</p>
10627<p>
10628No concensus on that vote.
10629</p>
10630<p>
10631Hans to improve wording in consultation with Pete. Leave Open.
10632</p>
10633</blockquote>
10634
10635<p><i>[
106362009-10 Santa Cruz:
10637]</i></p>
10638
10639
10640<blockquote>
10641Move to Ready. Ask Editor to clear up wording a little when integrating to
10642make it clear that the portion after the first comma only applies for
10643the presence of data races.
10644</blockquote>
10645
10646<p><i>[
106472009-10-24 Hans adds:
10648]</i></p>
10649
10650
10651<blockquote>
10652<p>
10653I think we need to pull 896 back from ready, unfortunately.  My wording
10654doesn't say the right thing.
10655</p>
10656
10657<p>
10658I suspect we really want to say something along the lines of:
10659</p>
10660
10661<blockquote>
10662For purposes of determining the presence of a data race, member
10663functions access and modify only the <tt>shared_ptr</tt> and
10664<tt>weak_ptr</tt> objects themselves and not objects they refer to.
10665Changes in <tt>use_count()</tt> do not reflect modifications that can
10666introduce data races.
10667</blockquote>
10668
10669<p>
10670But I think this needs further discussion by experts to make sure this
10671is right.
10672</p>
10673
10674<p>
10675Detlef and I agree continue to disagree on the resolution, but I think
10676we agree that it would be good to try to expedite this so that it can be
10677in CD2, since it's likely to generate NB comments no matter what we do.
10678And lack of clarity of intent is probably the worst option.  I think it
10679would be good to look at this between meetings.
10680</p>
10681</blockquote>
10682
10683
10684
10685<p><b>Proposed resolution:</b></p>
10686<p>
10687Make it explicitly thread-safe, in this weak sense, as I believe was intended:
10688</p>
10689<p>
10690Insert in 20.8.15.2 [util.smartptr.shared], before p5:
10691</p>
10692<blockquote>
10693<p>
10694For purposes of determining the presence of a data race,
10695member functions do not modify <tt>const shared_ptr</tt> and
10696const <tt>weak_ptr</tt> arguments, nor any objects they
10697refer to.  [<i>Note:</i> This is true in spite of that fact that such functions often
10698cause a change in <tt>use_count()</tt> <i>--end note</i>]
10699</p>
10700</blockquote>
10701<p>
10702On looking at the text, I'm not sure we need a similar disclaimer
10703anywhere else, since nothing else has the problem with the modified
10704<tt>use_count()</tt>.  I think Howard arrived at a similar conclusion.
10705</p>
10706
10707
10708
10709
10710
10711<hr>
10712<h3><a name="900"></a>900. stream move-assignment</h3>
10713<p><b>Section:</b> 27.9.1.8 [ifstream.assign] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
10714 <b>Submitter:</b> Niels Dekker <b>Opened:</b> 2008-09-20  <b>Last modified:</b> 2009-10-20</p>
10715<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
10716<p><b>Discussion:</b></p>
10717<p>
10718It
10719appears that we have an issue similar to issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#675">675</a> regarding the move-assignment of
10720stream types. For example, when assigning to an <tt>std::ifstream</tt>,
10721<tt>ifstream1</tt>, it seems preferable to close the file originally held by
10722<tt>ifstream1</tt>:
10723</p>
10724
10725<blockquote><pre>ifstream1 = std::move(ifstream2); 
10726</pre></blockquote>
10727
10728<p>
10729The current Draft
10730(<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2723.pdf">N2723</a>)
10731specifies that the move-assignment of
10732stream types like <tt>ifstream</tt> has the same effect as a swap:
10733</p>
10734
10735<blockquote>
10736<p>
10737Assign and swap 27.9.1.8 [ifstream.assign]
10738</p>
10739<pre>basic_ifstream&amp; operator=(basic_ifstream&amp;&amp; rhs); 
10740</pre>
10741<blockquote>
10742<i>Effects:</i> <tt>swap(rhs)</tt>.
10743</blockquote>
10744</blockquote>
10745
10746<p><i>[
10747Batavia (2009-05):
10748]</i></p>
10749
10750<blockquote>
10751<p>
10752Howard agrees with the analysis and the direction proposed.
10753</p>
10754<p>
10755Move to Open pending specific wording to be supplied by Howard.
10756</p>
10757</blockquote>
10758
10759<p><i>[
107602009-07 Frankfurt:
10761]</i></p>
10762
10763
10764<blockquote>
10765Howard is going to write wording.
10766</blockquote>
10767
10768<p><i>[
107692009-07-26 Howard provided wording.
10770]</i></p>
10771
10772
10773<p><i>[
107742009-09-13 Niels adds:
10775]</i></p>
10776
10777
10778<blockquote>
10779Note: The proposed change of 27.9.1.3 [filebuf.assign]/1 depends on the
10780resolution of LWG <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1204">1204</a>, which allows implementations to assume that
10781<tt>*this</tt> and <tt>rhs</tt> refer to different objects.
10782</blockquote>
10783
10784<p><i>[
107852009 Santa Cruz:
10786]</i></p>
10787
10788
10789<blockquote>
10790Leave as Open.  Too closely related to <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#911">911</a> to move on at this time.
10791</blockquote>
10792
10793
10794
10795<p><b>Proposed resolution:</b></p>
10796
10797<p>
10798Change 27.8.1.2 [stringbuf.assign]/1:
10799</p>
10800
10801<blockquote><pre>basic_stringbuf&amp; operator=(basic_stringbuf&amp;&amp; rhs);
10802</pre>
10803<blockquote>
10804-1- <i>Effects:</i> <del><tt>swap(rhs)</tt>.</del>
10805<ins>After the move assignment <tt>*this</tt> reflects the same observable
10806state it would have if it had been move constructed from <tt>rhs</tt>
10807(27.8.1.1 [stringbuf.cons]).
10808</ins>
10809</blockquote>
10810</blockquote>
10811
10812<p>
10813Change 27.8.2.2 [istringstream.assign]/1:
10814</p>
10815
10816<blockquote><pre>basic_istringstream&amp; operator=(basic_istringstream&amp;&amp; rhs);
10817</pre>
10818<blockquote>
10819-1- <i>Effects:</i> <del><tt>swap(rhs)</tt>.</del>
10820<ins>Move assigns the base and members of <tt>*this</tt> with the respective
10821base and members of <tt>rhs</tt>.
10822</ins>
10823</blockquote>
10824</blockquote>
10825
10826<p>
10827Change 27.8.3.2 [ostringstream.assign]/1:
10828</p>
10829
10830<blockquote><pre>basic_ostringstream&amp; operator=(basic_ostringstream&amp;&amp; rhs);
10831</pre>
10832<blockquote>
10833-1- <i>Effects:</i> <del><tt>swap(rhs)</tt>.</del>
10834<ins>Move assigns the base and members of <tt>*this</tt> with the respective
10835base and members of <tt>rhs</tt>.
10836</ins>
10837</blockquote>
10838</blockquote>
10839
10840<p>
10841Change 27.8.5.1 [stringstream.assign]/1:
10842</p>
10843
10844<blockquote><pre>basic_stringstream&amp; operator=(basic_stringstream&amp;&amp; rhs);
10845</pre>
10846<blockquote>
10847-1- <i>Effects:</i> <del><tt>swap(rhs)</tt>.</del>
10848<ins>Move assigns the base and members of <tt>*this</tt> with the respective
10849base and members of <tt>rhs</tt>.
10850</ins>
10851</blockquote>
10852</blockquote>
10853
10854<p>
10855Change 27.9.1.3 [filebuf.assign]/1:
10856</p>
10857
10858<blockquote><pre>basic_filebuf&amp; operator=(basic_filebuf&amp;&amp; rhs);
10859</pre>
10860<blockquote>
10861-1- <i>Effects:</i> <del><tt>swap(rhs)</tt>.</del>
10862<ins>Begins by calling <tt>this-&gt;close()</tt>.
10863After the move assignment <tt>*this</tt> reflects the same observable
10864state it would have if it had been move constructed from <tt>rhs</tt>
10865(27.9.1.2 [filebuf.cons]).
10866</ins>
10867</blockquote>
10868</blockquote>
10869
10870<p>
10871Change 27.9.1.8 [ifstream.assign]/1:
10872</p>
10873
10874<blockquote><pre>basic_ifstream&amp; operator=(basic_ifstream&amp;&amp; rhs);
10875</pre>
10876<blockquote>
10877-1- <i>Effects:</i> <del><tt>swap(rhs)</tt>.</del>
10878<ins>Move assigns the base and members of <tt>*this</tt> with the respective
10879base and members of <tt>rhs</tt>.</ins>
10880</blockquote>
10881</blockquote>
10882
10883<p>
10884Change 27.9.1.12 [ofstream.assign]/1:
10885</p>
10886
10887<blockquote><pre>basic_ofstream&amp; operator=(basic_ofstream&amp;&amp; rhs);
10888</pre>
10889<blockquote>
10890-1- <i>Effects:</i> <del><tt>swap(rhs)</tt>.</del>
10891<ins>Move assigns the base and members of <tt>*this</tt> with the respective
10892base and members of <tt>rhs</tt>.</ins>
10893</blockquote>
10894</blockquote>
10895
10896<p>
10897Change 27.9.1.16 [fstream.assign]/1:
10898</p>
10899
10900<blockquote><pre>basic_fstream&amp; operator=(basic_fstream&amp;&amp; rhs);
10901</pre>
10902<blockquote>
10903-1- <i>Effects:</i> <del><tt>swap(rhs)</tt>.</del>
10904<ins>Move assigns the base and members of <tt>*this</tt> with the respective
10905base and members of <tt>rhs</tt>.</ins>
10906</blockquote>
10907</blockquote>
10908
10909
10910
10911
10912
10913
10914<hr>
10915<h3><a name="910"></a>910. Effects of MoveAssignable</h3>
10916<p><b>Section:</b> 20.2.1 [utility.arg.requirements] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
10917 <b>Submitter:</b> Alberto Ganesh Barbati <b>Opened:</b> 2008-09-29  <b>Last modified:</b> 2009-11-03</p>
10918<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#utility.arg.requirements">active issues</a> in [utility.arg.requirements].</p>
10919<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#utility.arg.requirements">issues</a> in [utility.arg.requirements].</p>
10920<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
10921<p><b>Discussion:</b></p>
10922<p><b>Addresses UK 150</b></p>
10923
10924<p>
10925The description of the effect of <tt>operator=</tt> in the <tt>MoveAssignable</tt>
10926concept, given in paragraph 7 is:
10927</p>
10928
10929<blockquote><pre>result_type  T::operator=(T&amp;&amp;  rv);  // inherited from HasAssign&lt;T, T&amp;&amp;&gt;
10930</pre>
10931
10932<blockquote>
10933<i>Postconditions:</i> the constructed <tt>T</tt> object is equivalent to the value of
10934<tt>rv</tt> before the assignment. [<i>Note:</i> there is no
10935requirement on the value of <tt>rv</tt> after the assignment.  <i>--end note</i>]
10936</blockquote>
10937</blockquote>
10938
10939<p>
10940The sentence contains a typo (what is the "constructed <tt>T</tt> object"?)
10941probably due to a cut&amp;paste from <tt>MoveConstructible</tt>. Moreover, the
10942discussion of LWG issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#675">675</a> shows that the postcondition is too generic
10943and might not reflect the user expectations. An implementation of the
10944move assignment that just calls <tt>swap()</tt> would always fulfill the
10945postcondition as stated, but might have surprising side-effects in case
10946the source rvalue refers to an object that is not going to be
10947immediately destroyed. See LWG issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#900">900</a> for another example. Due to
10948the sometimes intangible nature of the "user expectation", it seems
10949difficult to have precise normative wording that could cover all cases
10950without introducing unnecessary restrictions. However a non-normative
10951clarification could be a very helpful warning sign that swapping is not
10952always the correct thing to do.
10953</p>
10954
10955<p><i>[
109562009-05-09 Alisdair adds:
10957]</i></p>
10958
10959
10960<blockquote>
10961<p>
10962Issue 910 is exactly the reason BSI advanced the Editorial comment UK-150.
10963</p>
10964<p>
10965The post-conditions after assignment are at a minimum that the object
10966referenced by rv must be safely destructible, and the transaction should not
10967leak resources.  Ideally it should be possible to simply assign rv a new
10968valid state after the call without invoking undefined behaviour, but any
10969other use of the referenced object would depend upon additional guarantees
10970made by that type.
10971</p>
10972</blockquote>
10973
10974<p><i>[
109752009-05-09 Howard adds:
10976]</i></p>
10977
10978
10979<blockquote>
10980<p>
10981The intent of the rvalue reference work is that the moved from <tt>rv</tt> is
10982a valid object.  Not one in a singular state.  If, for example, the moved from
10983object is a <tt>vector</tt>, one should be able to do anything on that moved-from
10984<tt>vector</tt> that you can do with any other <tt>vector</tt>.  However you would
10985first have to query it to find out what its current state is.  E.g. it might have <tt>capacity</tt>,
10986it might not.  It might have a non-zero <tt>size</tt>, it might not.  But regardless,
10987you can <tt>push_back</tt> on to it if you want.
10988</p>
10989
10990<p>
10991That being said, most standard code is now conceptized.  That is, the concepts
10992list the only operations that can be done with templated types - whether or not
10993the values have been moved from.
10994</p>
10995
10996<p>
10997Here is user-written code which must be allowed to be legal:
10998</p>
10999<blockquote><pre>#include &lt;vector&gt;
11000#include &lt;cstdio&gt;
11001
11002template &lt;class Allocator&gt;
11003void
11004inspect(std::vector&lt;double, Allocator&gt;&amp;&amp; v)
11005{
11006    std::vector&lt;double, Allocator&gt; result(move(v));
11007    std::printf("moved from vector has %u size and %u capacity\n", v.size(), v.capacity());
11008    std::printf("The contents of the vector are:\n");
11009    typedef typename std::vector&lt;double, Allocator&gt;::iterator I;
11010    for (I i = v.begin(), e = v.end(); i != e; ++i)
11011        printf("%f\n", *i);
11012}
11013
11014int main()
11015{
11016    std::vector&lt;double&gt; v1(100, 5.5);
11017    inspect(move(v1));
11018}
11019</pre></blockquote>
11020
11021<p>
11022The above program does not treat the moved-from <tt>vector</tt> as singular.  It
11023only treats it as a <tt>vector</tt> with an unknown value.
11024</p>
11025<p>
11026I believe the current proposed wording is consistent with my view on this.
11027</p>
11028</blockquote>
11029
11030<p><i>[
11031Batavia (2009-05):
11032]</i></p>
11033
11034<blockquote>
11035We agree that the proposed resolution
11036is an improvement over the current wording.
11037</blockquote>
11038
11039<p><i>[
110402009-07 Frankfurt:
11041]</i></p>
11042
11043
11044<blockquote>
11045Need to look at again without concepts.
11046</blockquote>
11047
11048<p><i>[
110492009-07 Frankfurt:
11050]</i></p>
11051
11052
11053<blockquote>
11054Walter will consult with Dave and Doug.
11055</blockquote>
11056
11057<p><i>[
110582009-10 Santa Cruz:
11059]</i></p>
11060
11061
11062<blockquote>
11063We believe this is handled by the resolution to issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1204">1204</a>,
11064but there is to much going on in this area to be sure.  Defer for now.
11065</blockquote>
11066
11067
11068
11069<p><b>Proposed resolution:</b></p>
11070<p>
11071In  [concept.copymove], replace the postcondition in paragraph 7 with:
11072</p>
11073
11074<blockquote>
11075<i>Postconditions:</i> <tt>*this</tt> is equivalent to the value of <tt>rv</tt> before the
11076assignment. [<i>Note:</i> there is no requirement on the value of <tt>rv</tt> after the
11077assignment, but the
11078effect should be unsurprising to the user even in case <tt>rv</tt> is not
11079immediately destroyed. This may require that resources previously owned
11080by <tt>*this</tt> are released instead of transferred to <tt>rv</tt>. <i>-- end note</i>]
11081</blockquote>
11082
11083
11084
11085
11086
11087<hr>
11088<h3><a name="911"></a>911. I/O streams and <tt>move/swap</tt> semantic</h3>
11089<p><b>Section:</b> 27.7.1 [input.streams], 27.7.2 [output.streams] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
11090 <b>Submitter:</b> Alberto Ganesh Barbati <b>Opened:</b> 2008-09-29  <b>Last modified:</b> 2009-10-20</p>
11091<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
11092<p><b>Discussion:</b></p>
11093<p>
11094Class template <tt>basic_istream</tt>, <tt>basic_ostream</tt> and <tt>basic_iostream</tt>
11095implements public move constructors, move assignment operators and <tt>swap</tt>
11096method and free functions. This might induce both the user and the
11097compiler to think that those types are <tt>MoveConstructible</tt>, <tt>MoveAssignable</tt>
11098and <tt>Swappable</tt>. However, those class templates fail to fulfill the user
11099expectations. For example:
11100</p>
11101
11102<blockquote><pre>std::ostream os(std::ofstream("file.txt"));
11103assert(os.rdbuf() == 0); // buffer object is not moved to os, file.txt has been closed
11104
11105std::vector&lt;std::ostream&gt; v;
11106v.push_back(std::ofstream("file.txt"));
11107v.reserve(100); // causes reallocation
11108assert(v[0].rdbuf() == 0); // file.txt has been closed!
11109
11110std::ostream&amp;&amp; os1 = std::ofstream("file1.txt");
11111os1 = std::ofstream("file2.txt");
11112os1 &lt;&lt; "hello, world"; // still writes to file1.txt, not to file2.txt!
11113
11114std::ostream&amp;&amp; os1 = std::ofstream("file1.txt");
11115std::ostream&amp;&amp; os2 = std::ofstream("file2.txt");
11116std::swap(os1, os2);
11117os1 &lt;&lt; "hello, world"; // writes to file1.txt, not to file2.txt!
11118</pre></blockquote>
11119
11120<p>
11121This is because the move constructor, the move assignment operator and
11122<tt>swap</tt> are all implemented through calls to <tt>std::basic_ios</tt> member
11123functions <tt>move()</tt> and <tt>swap()</tt> that do not move nor swap the controlled
11124stream buffers. That can't happen because the stream buffers may have
11125different types.
11126</p>
11127
11128<p>
11129Notice that for <tt>basic_streambuf</tt>, the member function <tt>swap()</tt> is
11130protected. I believe that is correct and all of <tt>basic_istream</tt>,
11131<tt>basic_ostream</tt>, <tt>basic_iostream</tt> should do the same as the move ctor, move
11132assignment operator and swap member function are needed by the derived
11133<tt>fstream</tt>s and <tt>stringstream</tt>s template. The free swap functions for
11134<tt>basic_(i|o|io)stream</tt> templates should be removed for the same reason.
11135</p>
11136
11137<p><i>[
11138Batavia (2009-05):
11139]</i></p>
11140
11141<blockquote>
11142<p>
11143We note that the rvalue swap functions have already been removed.
11144</p>
11145<p>
11146Bill is unsure about making the affected functions protected;
11147he believes they may need to be public.
11148</p>
11149<p>
11150We are also unsure about removing the lvalue swap functions as proposed.
11151</p>
11152<p>
11153Move to Open.
11154</p>
11155</blockquote>
11156
11157<p><i>[
111582009-07 Frankfurt:
11159]</i></p>
11160
11161
11162<blockquote>
11163<p>
11164It's not clear that the use case is compelling.
11165</p>
11166<p>
11167Howard: This needs to be implemented and tested.
11168</p>
11169</blockquote>
11170
11171<p><i>[
111722009-07-26 Howard adds:
11173]</i></p>
11174
11175
11176<blockquote>
11177<p>
11178I started out thinking I would recommend NAD for this one.  I've turned around
11179to agree with the proposed resolution (which I've updated to the current draft).
11180I did not fully understand Ganesh's rationale, and attempt to describe my
11181improved understanding below.
11182</p>
11183
11184<p>
11185The move constructor, move assignment operator, and swap function are different
11186for <tt>basic_istream</tt>, <tt>basic_ostream</tt> and <tt>basic_iostream</tt>
11187than other classes.  A timely conversation with Daniel reminded me of this long
11188forgotten fact.  These members are sufficiently different that they would be
11189extremely confusing to use in general, but they are very much needed for derived
11190clients.
11191</p>
11192
11193<ul>
11194<li>
11195The move constructor moves everything but the <tt>rdbuf</tt> pointer.
11196</li>
11197<li>
11198The move assignment operator moves everything but the <tt>rdbuf</tt> pointer.
11199</li>
11200<li>
11201The swap function swaps everything but the <tt>rdbuf</tt> pointer.
11202</li>
11203</ul>
11204
11205<p>
11206The reason for this behavior is that for the std-derived classes (stringstreams,
11207filestreams), the <tt>rdbuf</tt> pointer points back into the class itself
11208(self referencing).  It can't be swapped or moved.  But this fact isn't born out
11209at the <tt>stream</tt> level.  Rather it is born out at the <tt>fstream</tt>/<tt>sstream</tt>
11210level.  And the lower levels just need to deal with that fact by not messing around
11211with the <tt>rdbuf</tt> pointer which is stored down at the lower levels.
11212</p>
11213
11214<p>
11215In a nutshell, it is very confusing for all of those who are not so intimately
11216related with streams that they've implemented them.  And it is even fairly
11217confusing for some of those who have (including myself).  I do not think it is
11218safe to swap or move <tt>istreams</tt> or <tt>ostreams</tt> because this will
11219(by necessary design) separate stream state from streambuffer state.  Derived
11220classes (such as <tt>fstream</tt> and <tt>stringstream</tt> must be used to
11221keep the stream state and stream buffer consistently packaged as one unit during
11222a move or swap.
11223</p>
11224
11225<p>
11226I've implemented this proposal and am living with it day to day.
11227</p>
11228
11229</blockquote>
11230
11231<p><i>[
112322009 Santa Cruz:
11233]</i></p>
11234
11235
11236<blockquote>
11237Leave Open.  Pablo expected to propose alternative wording which would rename
11238move construction, move assignment and swap, and may or may not make them
11239protected.  This will impact issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#900">900</a>.
11240</blockquote>
11241
11242
11243
11244<p><b>Proposed resolution:</b></p>
11245<p>
1124627.7.1.1 [istream]: make the following member functions protected:
11247</p>
11248
11249<blockquote><pre>basic_istream(basic_istream&amp;&amp;  rhs);
11250basic_istream&amp;  operator=(basic_istream&amp;&amp;  rhs);
11251void  swap(basic_istream&amp;  rhs);
11252</pre></blockquote>
11253
11254<p>
11255Ditto: remove the swap free function signature
11256</p>
11257
11258<blockquote><pre><del>// swap: 
11259template &lt;class charT, class traits&gt; 
11260  void swap(basic_istream&lt;charT, traits&gt;&amp; x, basic_istream&lt;charT, traits&gt;&amp; y);</del>
11261</pre></blockquote>
11262
11263<p>
1126427.7.1.1.2 [istream.assign]: remove paragraph 4
11265</p>
11266
11267<blockquote><pre><del>template &lt;class charT, class traits&gt; 
11268  void swap(basic_istream&lt;charT, traits&gt;&amp; x, basic_istream&lt;charT, traits&gt;&amp; y);</del>
11269</pre>
11270<blockquote>
11271<del><i>Effects:</i> <tt>x.swap(y)</tt>.</del>
11272</blockquote>
11273</blockquote>
11274
11275<p>
1127627.7.1.5 [iostreamclass]: make the following member function protected:
11277</p>
11278
11279<blockquote><pre>basic_iostream(basic_iostream&amp;&amp;  rhs);
11280basic_iostream&amp;  operator=(basic_iostream&amp;&amp;  rhs);
11281void  swap(basic_iostream&amp;  rhs);
11282</pre></blockquote>
11283
11284<p>
11285Ditto: remove the swap free function signature
11286</p>
11287
11288<blockquote><pre><del>template &lt;class charT, class traits&gt; 
11289  void swap(basic_iostream&lt;charT, traits&gt;&amp; x, basic_iostream&lt;charT, traits&gt;&amp; y);</del>
11290</pre></blockquote>
11291
11292<p>
1129327.7.1.5.3 [iostream.assign]: remove paragraph 3
11294</p>
11295
11296<blockquote><pre><del>template &lt;class charT, class traits&gt; 
11297  void swap(basic_iostream&lt;charT, traits&gt;&amp; x, basic_iostream&lt;charT, traits&gt;&amp; y);</del>
11298</pre>
11299<blockquote>
11300<del><i>Effects:</i> <tt>x.swap(y)</tt>.</del>
11301</blockquote>
11302</blockquote>
11303
11304<p>
1130527.7.2.1 [ostream]: make the following member function protected:
11306</p>
11307
11308<blockquote><pre>basic_ostream(basic_ostream&amp;&amp;  rhs);
11309basic_ostream&amp;  operator=(basic_ostream&amp;&amp;  rhs);
11310void  swap(basic_ostream&amp;  rhs);
11311</pre></blockquote>
11312
11313<p>
11314Ditto: remove the swap free function signature
11315</p>
11316
11317<blockquote><pre><del>// swap: 
11318template &lt;class charT, class traits&gt; 
11319  void swap(basic_ostream&lt;charT, traits&gt;&amp; x, basic_ostream&lt;charT, traits&gt;&amp; y);</del>
11320</pre></blockquote>
11321
11322<p>
1132327.7.2.3 [ostream.assign]: remove paragraph 4 
11324</p>
11325
11326<blockquote><pre><del>template &lt;class charT, class traits&gt; 
11327  void swap(basic_ostream&lt;charT, traits&gt;&amp; x, basic_ostream&lt;charT, traits&gt;&amp; y);</del>
11328</pre>
11329<blockquote>
11330<del><i>Effects:</i> <tt>x.swap(y)</tt>.</del>
11331</blockquote>
11332</blockquote>
11333
11334
11335
11336
11337
11338
11339<hr>
11340<h3><a name="915"></a>915. <tt>minmax</tt> with <tt>initializer_list</tt> should return
11341<tt>pair</tt> of <tt>T</tt>, not <tt>pair</tt> of <tt>const T&amp;</tt></h3>
11342<p><b>Section:</b> 25.4.7 [alg.min.max] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
11343 <b>Submitter:</b> Daniel Kr�gler <b>Opened:</b> 2008-10-04  <b>Last modified:</b> 2009-10-23</p>
11344<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#alg.min.max">issues</a> in [alg.min.max].</p>
11345<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
11346<p><b>Discussion:</b></p>
11347<p>
11348It seems that the proposed changes for
11349<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2772.pdf">N2772</a>
11350were not clear enough in
11351this point:
11352</p>
11353
11354<blockquote>
1135525.4.7 [alg.min.max], before p.23 + p.24 + before p. 27 + p. 28 say that the return
11356type of the <tt>minmax</tt> overloads with an <tt>initializer_list</tt> is
11357<tt>pair&lt;const T&amp;, const T&amp;&gt;</tt>,
11358which is inconsistent with the decision for the other <tt>min/max</tt> overloads which take
11359a <tt>initializer_list</tt> as argument and return a <tt>T</tt>, not a <tt>const T&amp;</tt>.
11360Doing otherwise for <tt>minmax</tt> would easily lead to unexpected life-time
11361problems by using <tt>minmax</tt> instead of <tt>min</tt> and <tt>max</tt> separately.
11362</blockquote>
11363
11364<p><i>[
11365Batavia (2009-05):
11366]</i></p>
11367
11368<blockquote>
11369We agree with the proposed resolution.
11370Move to Tentatively Ready.
11371</blockquote>
11372
11373<p><i>[
113742009-07 Frankfurt
11375]</i></p>
11376
11377
11378<blockquote>
11379Moved from Tentatively Ready to Open only because the wording needs to be
11380tweaked for concepts removal.
11381</blockquote>
11382
11383<p><i>[
113842009-08-18 Daniel adds:
11385]</i></p>
11386
11387
11388<blockquote>
11389Recommend NAD since the proposed changes have already been performed
11390as part of editorial work of
11391<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2914.pdf">N2914</a>.
11392</blockquote>
11393
11394<p><i>[
113952009-10 Santa Cruz:
11396]</i></p>
11397
11398
11399<blockquote>
11400Can't find initializer_list form of minmax anymore, only variadic
11401version. Seems like we had an editing clash with concepts. Leave Open,
11402at least until editorial issues resolved. Bring this to Editor's
11403attention.
11404</blockquote>
11405
11406
11407
11408<p><b>Proposed resolution:</b></p>
11409<ol>
11410<li>
11411<p>
11412In 25 [algorithms]/2, header <tt>&lt;algorithm&gt;</tt> synopsis change as indicated:
11413</p>
11414
11415<blockquote><pre>template&lt;<del>class</del><ins>LessThanComparable</ins> T&gt;
11416<ins>requires CopyConstructible&lt;T&gt;</ins>
11417pair&lt;<del>const </del>T<del>&amp;</del>, <del>const </del>T<del>&amp;</del>&gt;
11418minmax(initializer_list&lt;T&gt; t);
11419
11420template&lt;class T, <del>class</del><ins>StrictWeakOrder&lt;auto, T&gt;</ins> Compare&gt;
11421<ins>requires CopyConstructible&lt;T&gt;</ins>
11422pair&lt;<del>const </del>T<del>&amp;</del>, <del>const </del>T<del>&amp;</del>&gt;
11423minmax(initializer_list&lt;T&gt; t, Compare comp);
11424</pre></blockquote>
11425</li>
11426<li>
11427<p>
11428In 25.4.7 [alg.min.max] change as indicated (Begin: Just before p.20):
11429</p>
11430<blockquote><pre>template&lt;<del>class</del><ins>LessThanComparable</ins> T&gt;
11431  <ins>requires CopyConstructible&lt;T&gt;</ins>
11432  pair&lt;<del>const </del>T<del>&amp;</del>, <del>const </del>T<del>&amp;</del>&gt;
11433  minmax(initializer_list&lt;T&gt; t);
11434</pre>
11435<blockquote>
11436<p>
11437<del>-20- <i>Requires:</i> <tt>T</tt> is <tt>LessThanComparable</tt> and
11438<tt>CopyConstructible</tt>.</del>
11439</p>
11440<p>
11441-21- <i>Returns:</i> <tt>pair&lt;<del>const </del>T<del>&amp;</del>, <del>const
11442</del>T<del>&amp;</del>&gt;(x, y)</tt> where <tt>x</tt> is the
11443smallest value and <tt>y</tt> the largest value in the <tt>initializer_list</tt>.
11444</p>
11445</blockquote>
11446
11447<p>[..]</p>
11448<pre>template&lt;class T, <del>class</del><ins>StrictWeakOrder&lt;auto, T&gt;</ins> Compare&gt;
11449  <ins>requires CopyConstructible&lt;T&gt;</ins>
11450  pair&lt;<del>const </del>T<del>&amp;</del>, <del>const </del>T<del>&amp;</del>&gt;
11451  minmax(initializer_list&lt;T&gt; t, Compare comp);
11452</pre>
11453
11454<blockquote>
11455<p>
11456<del>-24- <i>Requires:</i> type <tt>T</tt> is <tt>LessThanComparable</tt> and <tt>CopyConstructible</tt>.</del>
11457</p>
11458<p>
11459-25- <i>Returns:</i> <tt>pair&lt;<del>const </del>T<del>&amp;</del>, <del>const
11460</del>T<del>&amp;</del>&gt;(x, y)</tt> where <tt>x</tt> is the
11461smallest value and <tt>y</tt> largest value in the <tt>initializer_list</tt>.
11462</p>
11463</blockquote>
11464</blockquote>
11465</li>
11466</ol>
11467
11468
11469
11470
11471
11472
11473<hr>
11474<h3><a name="920"></a>920. Ref-qualification support in the library</h3>
11475<p><b>Section:</b> 20.7.14 [func.memfn] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
11476 <b>Submitter:</b> Bronek Kozicki <b>Opened:</b> 2008-10-06  <b>Last modified:</b> 2009-10-23</p>
11477<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#func.memfn">issues</a> in [func.memfn].</p>
11478<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
11479<p><b>Duplicate of:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1230">1230</a></p>
11480<p><b>Discussion:</b></p>
11481<p>
11482Daniel Kr�gler wrote:
11483</p>
11484
11485<blockquote>
11486<p>
11487Shouldn't above list be completed for &amp;- and &amp;&amp;-qualified
11488member functions This would cause to add:
11489</p>
11490<blockquote><pre>template&lt;Returnable R, class T, CopyConstructible... Args&gt;
11491unspecified mem_fn(R (T::* pm)(Args...) &amp;);
11492template&lt;Returnable R, class T, CopyConstructible... Args&gt;
11493unspecified mem_fn(R (T::* pm)(Args...) const &amp;);
11494template&lt;Returnable R, class T, CopyConstructible... Args&gt;
11495unspecified mem_fn(R (T::* pm)(Args...) volatile &amp;);
11496template&lt;Returnable R, class T, CopyConstructible... Args&gt;
11497unspecified mem_fn(R (T::* pm)(Args...) const volatile &amp;);
11498template&lt;Returnable R, class T, CopyConstructible... Args&gt;
11499unspecified mem_fn(R (T::* pm)(Args...) &amp;&amp;);
11500template&lt;Returnable R, class T, CopyConstructible... Args&gt;
11501unspecified mem_fn(R (T::* pm)(Args...) const &amp;&amp;);
11502template&lt;Returnable R, class T, CopyConstructible... Args&gt;
11503unspecified mem_fn(R (T::* pm)(Args...) volatile &amp;&amp;);
11504template&lt;Returnable R, class T, CopyConstructible... Args&gt;
11505unspecified mem_fn(R (T::* pm)(Args...) const volatile &amp;&amp;);
11506</pre></blockquote>
11507
11508</blockquote>
11509
11510<p>
11511yes, absolutely. Thanks for spotting this. Without this change <tt>mem_fn</tt>
11512cannot be initialized from pointer to ref-qualified member function. I
11513believe semantics of such function pointer is well defined.
11514</p>
11515
11516<p><i>[
11517Post Summit Daniel provided wording.
11518]</i></p>
11519
11520
11521<p><i>[
11522Batavia (2009-05):
11523]</i></p>
11524
11525<blockquote>
11526<p>
11527We need to think about whether we really want to go down the proposed path
11528of combinatorial explosion.
11529Perhaps a Note would suffice.
11530</p>
11531<p>
11532We would really like to have an implementation before proceeding.
11533</p>
11534<p>
11535Move to Open, and recommend this be deferred until after the next
11536Committee Draft has been issued.
11537</p>
11538</blockquote>
11539
11540<p><i>[
115412009-10-10 Daniel updated wording to post-concepts.
11542]</i></p>
11543
11544
11545<blockquote>
11546<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1230">1230</a> has a similar proposed resolution
11547</blockquote>
11548
11549<p><i>[
115502009-10 Santa Cruz:
11551]</i></p>
11552
11553
11554<blockquote>
11555Move to Ready.
11556</blockquote>
11557
11558
11559
11560<p><b>Proposed resolution:</b></p>
11561<ol>
11562<li>
11563<p>
11564Change 20.7 [function.objects]/2, header
11565<tt>&lt;functional&gt;</tt> synopsis as follows:
11566</p>
11567
11568<blockquote><pre>// 20.7.14, member function adaptors:
11569template&lt;class R, class T&gt; <i>unspecified</i> mem_fn(R T::*);
11570
11571<ins>template&lt;class R, class T, class ...Args&gt; <i>unspecified</i> mem_fn(R (T::*)(Args...));</ins>
11572<ins>template&lt;class R, class T, class ...Args&gt; <i>unspecified</i> mem_fn(R (T::*)(Args...) const);</ins>
11573<ins>template&lt;class R, class T, class ...Args&gt; <i>unspecified</i> mem_fn(R (T::*)(Args...) volatile);</ins>
11574<ins>template&lt;class R, class T, class ...Args&gt; <i>unspecified</i> mem_fn(R (T::*)(Args...) const volatile);</ins>
11575
11576<ins>template&lt;class R, class T, class ...Args&gt; <i>unspecified</i> mem_fn(R (T::*)(Args...) &amp;);</ins>
11577<ins>template&lt;class R, class T, class ...Args&gt; <i>unspecified</i> mem_fn(R (T::*)(Args...) const &amp;);</ins>
11578<ins>template&lt;class R, class T, class ...Args&gt; <i>unspecified</i> mem_fn(R (T::*)(Args...) volatile &amp;);</ins>
11579<ins>template&lt;class R, class T, class ...Args&gt; <i>unspecified</i> mem_fn(R (T::*)(Args...) const volatile &amp;);</ins>
11580
11581<ins>template&lt;class R, class T, class ...Args&gt; <i>unspecified</i> mem_fn(R (T::*)(Args...) &amp;&amp;);</ins>
11582<ins>template&lt;class R, class T, class ...Args&gt; <i>unspecified</i> mem_fn(R (T::*)(Args...) const &amp;&amp;);</ins>
11583<ins>template&lt;class R, class T, class ...Args&gt; <i>unspecified</i> mem_fn(R (T::*)(Args...) volatile &amp;&amp;);</ins>
11584<ins>template&lt;class R, class T, class ...Args&gt; <i>unspecified</i> mem_fn(R (T::*)(Args...) const volatile &amp;&amp;);</ins>
11585</pre></blockquote>
11586</li>
11587
11588<li>
11589<p>
11590Change the prototype list of 20.7.14 [func.memfn] as follows [NB: The
11591following text, most notably p.2 and p.3 which
11592discuss influence of the cv-qualification on the definition of the
11593base class's first template parameter remains
11594unchanged. ]:
11595</p>
11596
11597<blockquote><pre>template&lt;class R, class T&gt; <i>unspecified</i> mem_fn(R T::* pm);
11598
11599<ins>template&lt;class R, class T, class ...Args&gt; <i>unspecified</i> mem_fn(R (T::* pm)(Args...));</ins>
11600<ins>template&lt;class R, class T, class ...Args&gt; <i>unspecified</i> mem_fn(R (T::* pm)(Args...) const);</ins>
11601<ins>template&lt;class R, class T, class ...Args&gt; <i>unspecified</i> mem_fn(R (T::* pm)(Args...) volatile);</ins>
11602<ins>template&lt;class R, class T, class ...Args&gt; <i>unspecified</i> mem_fn(R (T::* pm)(Args...) const volatile);</ins>
11603
11604<ins>template&lt;class R, class T, class ...Args&gt; <i>unspecified</i> mem_fn(R (T::* pm)(Args...) &amp;);</ins>
11605<ins>template&lt;class R, class T, class ...Args&gt; <i>unspecified</i> mem_fn(R (T::* pm)(Args...) const &amp;);</ins>
11606<ins>template&lt;class R, class T, class ...Args&gt; <i>unspecified</i> mem_fn(R (T::* pm)(Args...) volatile &amp;);</ins>
11607<ins>template&lt;class R, class T, class ...Args&gt; <i>unspecified</i> mem_fn(R (T::* pm)(Args...) const volatile &amp;);</ins>
11608
11609<ins>template&lt;class R, class T, class ...Args&gt; <i>unspecified</i> mem_fn(R (T::* pm)(Args...) &amp;&amp;);</ins>
11610<ins>template&lt;class R, class T, class ...Args&gt; <i>unspecified</i> mem_fn(R (T::* pm)(Args...) const &amp;&amp;);</ins>
11611<ins>template&lt;class R, class T, class ...Args&gt; <i>unspecified</i> mem_fn(R (T::* pm)(Args...) volatile &amp;&amp;);</ins>
11612<ins>template&lt;class R, class T, class ...Args&gt; <i>unspecified</i> mem_fn(R (T::* pm)(Args...) const volatile &amp;&amp;);</ins>
11613</pre></blockquote>
11614</li>
11615
11616<li>
11617<p>
11618Remove 20.7.14 [func.memfn]/5:
11619</p>
11620
11621<blockquote>
11622<del><i>Remarks:</i> Implementations may implement <tt>mem_fn</tt> as a set of
11623overloaded function templates.</del>
11624</blockquote>
11625</li>
11626</ol>
11627
11628
11629
11630
11631
11632
11633<hr>
11634<h3><a name="921"></a>921. Rational Arithmetic should use template aliases</h3>
11635<p><b>Section:</b> 20.4.1 [ratio.ratio] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
11636 <b>Submitter:</b> Pablo Halpern <b>Opened:</b> 2008-10-07  <b>Last modified:</b> 2009-10-21</p>
11637<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#ratio.ratio">issues</a> in [ratio.ratio].</p>
11638<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
11639<p><b>Discussion:</b></p>
11640<p>
11641The compile-time functions that operate on <tt>ratio&lt;N,D&gt;</tt> require the
11642cumbersome and error-prone "evaluation" of a <tt>type</tt> member using a
11643meta-programming style that predates the invention of template aliases.
11644Thus, multiplying three ratios <tt>a</tt>, <tt>b</tt>, and <tt>c</tt> requires the expression:
11645</p>
11646
11647<blockquote><pre>ratio_multiply&lt;a, ratio_multiply&lt;b, c&gt;::type&gt;::type
11648</pre></blockquote>
11649
11650<p>
11651The simpler expression:
11652</p>
11653
11654<blockquote><pre>ratio_multiply&lt;a, ratio_multiply&lt;b, c&gt;&gt;
11655</pre></blockquote>
11656
11657<p>
11658Could be used by if template aliases were employed in the definitions.
11659</p>
11660
11661<p><i>[
11662Post Summit:
11663]</i></p>
11664
11665
11666<blockquote>
11667<p>
11668Jens: not a complete proposed resolution: "would need to make similar change"
11669</p>
11670<p>
11671Consensus: We agree with the direction of the issue.
11672</p>
11673<p>
11674Recommend Open.
11675</p>
11676</blockquote>
11677
11678<p><i>[
116792009-05-11 Daniel adds:
11680]</i></p>
11681
11682
11683<blockquote>
11684<p>
11685Personally I'm <em>not</em> in favor for the addition of:
11686</p>
11687<blockquote><pre>typedef ratio type;
11688</pre></blockquote>
11689<p>
11690For a reader of the
11691standard it's usage or purpose is unclear. I haven't seen similar examples
11692of attempts to satisfy non-feature complete compilers.
11693</p>
11694</blockquote>
11695
11696<p><i>[
116972009-05-11 Pablo adds:
11698]</i></p>
11699
11700
11701<blockquote>
11702<p>
11703The addition of type to the <tt>ratio</tt> template allows the previous style
11704(i.e., in the prototype implementations) to remain valid and permits the
11705use of transitional library implementations for C++03 compilers.  I do
11706not feel strongly about its inclusion, however, and leave it up to the
11707reviewers to decide.
11708</p>
11709</blockquote>
11710
11711<p><i>[
11712Batavia (2009-05):
11713]</i></p>
11714
11715<blockquote>
11716Bill asks for additional discussion in the issue
11717that spells out more details of the implementation.
11718Howard points us to issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#948">948</a>
11719which has at least most of the requested details.
11720Tom is strongly in favor of overflow-checking at compile time.
11721Pete points out that there is no change of functionality implied.
11722We agree with the proposed resolution,
11723but recommend moving the issue to Review
11724to allow time to improve the discussion if needed.
11725</blockquote>
11726
11727<p><i>[
117282009-07-21 Alisdair adds:
11729]</i></p>
11730
11731
11732<blockquote>
11733See <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1121">1121</a> for a potentially incompatible proposal.
11734</blockquote>
11735
11736<p><i>[
117372009-10 Santa Cruz:
11738]</i></p>
11739
11740
11741<blockquote>
11742Move to Ready.
11743</blockquote>
11744
11745
11746
11747<p><b>Proposed resolution:</b></p>
11748
11749 
11750 <ol start="0">
11751<li>
11752<p>
11753In 20.4 [ratio]/3 change as indicated:
11754</p>
11755
11756<blockquote><pre>// ratio arithmetic
11757template &lt;class R1, class R2&gt; <del>struct</del><ins>using</ins> ratio_add<ins> = <em>see below</em></ins>;
11758template &lt;class R1, class R2&gt; <del>struct</del><ins>using</ins> ratio_subtract<ins> = <em>see below</em></ins>;
11759template &lt;class R1, class R2&gt; <del>struct</del><ins>using</ins> ratio_multiply<ins> = <em>see below</em></ins>;
11760template &lt;class R1, class R2&gt; <del>struct</del><ins>using</ins> ratio_divide<ins> = <em>see below</em></ins>;
11761</pre></blockquote>
11762</li>
11763<li>
11764<p>
11765In 20.4.1 [ratio.ratio], change as indicated:
11766</p>
11767<blockquote><pre>namespace std {
11768  template &lt;intmax_t N, intmax_t D = 1&gt;
11769  class ratio {
11770  public:
11771    <ins>typedef ratio type;</ins>
11772    static const intmax_t num;
11773    static const intmax_t den;
11774  };
11775}
11776</pre></blockquote>
11777</li>
11778<li>
11779<p>
11780In 20.4.2 [ratio.arithmetic] change as indicated:
11781</p>
11782
11783<blockquote><pre>template &lt;class R1, class R2&gt; <del>struct</del><ins>using</ins> ratio_add<ins> = <em>see below</em></ins><del>{
11784  typedef <em>see below</em> type;
11785}</del>;
11786</pre>
11787
11788<blockquote>
11789<p>
117901 The <del>nested typedef</del> type <tt><ins>ratio_add&lt;R1, R2&gt;</ins></tt>
11791shall be a synonym for <tt>ratio&lt;T1, T2&gt;</tt>
11792where <tt>T1</tt> has the value <tt>R1::num * R2::den + R2::num * R1::den</tt> and <tt>T2</tt>
11793has the value <tt>R1::den * R2::den</tt>.
11794</p>
11795</blockquote>
11796</blockquote>
11797<blockquote><pre>template &lt;class R1, class R2&gt; <del>struct</del><ins>using</ins> ratio_subtract<ins> = <em>see below</em></ins><del>{
11798  typedef <em>see below</em> type;
11799}</del>;
11800</pre>
11801<blockquote>
11802<p>
118032 The <del>nested typedef</del> type <tt><ins>ratio_subtract&lt;R1, R2&gt;</ins></tt>
11804shall be a synonym for <tt>ratio&lt;T1, T2&gt;</tt>
11805where <tt>T1</tt> has the value <tt>R1::num * R2::den - R2::num * R1::den</tt> and <tt>T2</tt>
11806has the value <tt>R1::den * R2::den</tt>.
11807</p>
11808</blockquote>
11809</blockquote>
11810<blockquote><pre>template &lt;class R1, class R2&gt; <del>struct</del><ins>using</ins> ratio_multiply<ins> = <em>see below</em></ins><del>{
11811  typedef <em>see below</em> type;
11812}</del>;
11813</pre>
11814<blockquote>
11815<p>
118163 The <del>nested typedef</del> type <tt><ins>ratio_multiply&lt;R1, R2&gt;</ins></tt>
11817shall be a synonym for <tt>ratio&lt;T1, T2&gt;</tt>
11818where <tt>T1</tt> has the value <tt>R1::num * R2::num</tt> and <tt>T2</tt> has the value <tt>R1::den * R2::den</tt>.
11819</p>
11820</blockquote>
11821</blockquote>
11822<blockquote><pre>template &lt;class R1, class R2&gt; <del>struct</del><ins>using</ins> ratio_divide<ins> = <em>see below</em></ins><del>{
11823  typedef <em>see below</em> type;
11824}</del>;
11825</pre>
11826<blockquote>
11827<p>
118284 The <del>nested typedef</del> type <tt><ins>ratio_divide&lt;R1, R2&gt;</ins></tt>
11829shall be a synonym for <tt>ratio&lt;T1, T2&gt;</tt>
11830where <tt>T1</tt> has the value <tt>R1::num * R2::den</tt> and <tt>T2</tt> has the value <tt>R1::den * R2::num</tt>.
11831</p>
11832</blockquote>
11833</blockquote>
11834</li>
11835<li>
11836<p>
11837In 20.9.3.1 [time.duration.cons]/4 change as indicated:
11838</p>
11839<blockquote>
11840<p>
11841<i>Requires:</i> <tt>treat_as_floating_point&lt;rep&gt;::value</tt> shall be true or
11842<tt>ratio_divide&lt;Period2, period&gt;::<del>type::</del>den</tt> shall be 1.[..]
11843</p>
11844</blockquote>
11845</li>
11846<li>
11847<p>
11848In 20.9.3.7 [time.duration.cast]/2 change as indicated:
11849</p>
11850<blockquote>
11851<p>
11852<i>Returns:</i> Let CF be <tt>ratio_divide&lt;Period, typename
11853ToDuration::period&gt;<del>::type</del></tt>, and [..]
11854</p>
11855</blockquote>
11856</li>
11857</ol>
11858
11859
11860
11861
11862
11863<hr>
11864<h3><a name="929"></a>929. Thread constructor</h3>
11865<p><b>Section:</b> 30.3.1.2 [thread.thread.constr] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Review">Review</a>
11866 <b>Submitter:</b> Anthony Williams <b>Opened:</b> 2008-10-23  <b>Last modified:</b> 2009-10-25</p>
11867<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#thread.thread.constr">active issues</a> in [thread.thread.constr].</p>
11868<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#thread.thread.constr">issues</a> in [thread.thread.constr].</p>
11869<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Review">Review</a> status.</p>
11870<p><b>Discussion:</b></p>
11871
11872<p><b>Addresses UK 323</b></p>
11873
11874<p>
11875The <tt>thread</tt> constructor for starting a new thread with a function and
11876arguments is overly constrained by the signature requiring rvalue
11877references for <tt>func</tt> and <tt>args</tt> and the <tt>CopyConstructible</tt> requirements
11878for the elements of <tt>args</tt>. The use of an rvalue reference for the
11879function restricts the potential use of a plain function name, since
11880the type of the bound parameter will be deduced to be a function
11881reference and decay to pointer-to-function will not happen. This
11882therefore complicates the implementation in order to handle a simple
11883case. Furthermore, the use of rvalue references for args prevents the
11884array to pointer decay. Since arrays are not <tt>CopyConstructible</tt> or even
11885<tt>MoveConstructible</tt>, this essentially prevents the passing of arrays as
11886parameters. In particular it prevents the passing of string literals.
11887Consequently a simple case such as
11888</p>
11889
11890<blockquote><pre>void f(const char*);
11891std::thread t(f,"hello");
11892</pre></blockquote>
11893
11894<p>
11895is ill-formed since the type of the string literal is <tt>const char[6]</tt>.
11896</p>
11897
11898<p>
11899By changing the signature to take all parameters by value we can
11900eliminate the <tt>CopyConstructible</tt> requirement and permit the use of
11901arrays, as the parameter passing semantics will cause the necessary
11902array-to-pointer decay. They will also cause the function name to
11903decay to a pointer to function and allow the implementation to handle
11904functions and function objects identically.
11905</p>
11906
11907<p>
11908The new signature of the <tt>thread</tt> constructor for a function and
11909arguments is thus:
11910</p>
11911
11912<blockquote><pre>template&lt;typename F,typename... Args&gt;
11913thread(F,Args... args);
11914</pre></blockquote>
11915
11916<p>
11917Since the parameter pack <tt>Args</tt> can be empty, the single-parameter
11918constructor that takes just a function by value is now redundant.
11919</p>
11920
11921<p><i>[
11922Howard adds:
11923]</i></p>
11924
11925
11926<blockquote>
11927<p>
11928I agree with everything Anthony says in this issue.  However I believe we
11929can optimize in such a way as to get the pass-by-value behavior with the
11930pass-by-rvalue-ref performance.  The performance difference is that the latter
11931removes a <tt>move</tt> when passing in an lvalue.
11932</p>
11933
11934<p>
11935This circumstance is very analogous to <tt>make_pair</tt> (20.3.4 [pairs])
11936where we started with passing by const reference, changed to pass by value to
11937get pointer decay, and then changed to pass by rvalue reference, but modified with
11938<tt>decay&lt;T&gt;</tt> to retain the pass-by-value behavior.  If we were to
11939apply the same solution here it would look like:
11940</p>
11941
11942<blockquote><pre><del>template &lt;class F&gt; explicit thread(F f);</del>
11943template &lt;class F, class ...Args&gt; thread(F&amp;&amp; f, Args&amp;&amp;... args);
11944</pre>
11945<blockquote>
11946<p>
11947-4- <i>Requires:</i> <tt>F</tt> and each <tt>Ti</tt> in <tt>Args</tt> shall be <del><tt>CopyConstructible</tt>
11948if an lvalue and otherwise</del> <tt>MoveConstructible</tt>.
11949<tt><i>INVOKE</i>(f, w1, w2, ..., wN)</tt> (20.7.2 [func.require]) shall be a valid expression for
11950some values <tt>w1, w2, ... , wN,</tt> where <tt>N == sizeof...(Args)</tt>.
11951</p>
11952<p>
11953-5- <i>Effects:</i> Constructs an object of type <tt>thread</tt>
11954<del>and executes <tt><i>INVOKE</i>(f, t1, t2, ..., tN)</tt> in a new
11955thread of execution, where <tt>t1, t2, ..., tN</tt> are the values in <tt>args...</tt></del>.
11956<ins>Constructs
11957the following objects in memory which is accessible to a new thread of execution
11958as if:</ins>
11959</p>
11960<blockquote><pre><ins>typename decay&lt;F&gt;::type g(std::forward&lt;F&gt;(f));</ins>
11961<ins>tuple&lt;typename decay&lt;Args&gt;::type...&gt; w(std::forward&lt;Args&gt;(args)...);</ins>
11962</pre></blockquote>
11963<p>
11964<ins>The new thread of
11965execution executes <tt><i>INVOKE</i>(g, wi...)</tt> where the <tt>wi...</tt> refers
11966to the elements stored in the <tt>tuple w</tt>.</ins>
11967Any return value from <tt>g</tt> is ignored.
11968<del>If <tt>f</tt> terminates with an uncaught exception, <tt>std::terminate()</tt> shall be called.</del>
11969<ins>If the evaluation of <tt><i>INVOKE</i>(g,  wi...)</tt> terminates
11970with an uncaught exception, <tt>std::terminate()</tt> shall be called [<i>Note:</i>
11971<tt>std::terminate()</tt> could be called before entering <tt>g</tt>. -- <i>end note</i>]. Any
11972exception thrown before the evaluation of <tt><i>INVOKE</i></tt> has started shall be
11973catchable in the calling thread.</ins>
11974</p>
11975</blockquote>
11976</blockquote>
11977
11978<p>
11979Text referring to when <tt>terminate()</tt> is called was contributed by Ganesh.
11980</p>
11981
11982</blockquote>
11983
11984<p><i>[
11985Batavia (2009-05):
11986]</i></p>
11987
11988<blockquote>
11989We agree with the proposed resolution,
11990but would like the final sentence to be reworded
11991since "catchable" is not a term of art (and is used nowhere else).
11992</blockquote>
11993
11994<p><i>[
119952009-07 Frankfurt:
11996]</i></p>
11997
11998
11999<blockquote>
12000<p>
12001This is linked to
12002<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2901.pdf">N2901</a>.
12003</p>
12004<p>
12005Howard to open a separate issue to remove (<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1176">1176</a>).
12006</p>
12007<p>
12008In Frankfurt there is no consensus for removing the variadic constructor.
12009</p>
12010</blockquote>
12011
12012<p><i>[
120132009-10 Santa Cruz:
12014]</i></p>
12015
12016
12017<blockquote>
12018We want to move forward with this issue.  If we later take it out via <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1176">1176</a>
12019then that's ok too.  Needs small group to improve wording.
12020</blockquote>
12021
12022<p><i>[
120232009-10 Santa Cruz:
12024]</i></p>
12025
12026
12027<blockquote>
12028<p>
12029Stefanus provided revised wording.  Moved to Review  Here is the original wording:
12030</p>
12031<blockquote>
12032<p>
12033Modify the class definition of <tt>std::thread</tt> in 30.3.1 [thread.thread.class] to remove the
12034following signature:
12035</p>
12036
12037<blockquote><pre><del>template&lt;class F&gt; explicit thread(F f);</del>
12038template&lt;class F, class ... Args&gt; <ins>explicit</ins> thread(F&amp;&amp; f, Args&amp;&amp; ... args);
12039</pre></blockquote>
12040
12041<p>
12042Modify 30.3.1.2 [thread.thread.constr] to replace the constructors prior to paragraph 4 with
12043the single constructor as above. Replace paragraph 4 - 6 with the
12044following:
12045</p>
12046
12047<blockquote>
12048<p>
12049-4- <i>Requires:</i> <tt>F</tt> and each <tt>Ti</tt> in <tt>Args</tt> shall be <del><tt>CopyConstructible</tt>
12050if an lvalue and otherwise</del> <tt>MoveConstructible</tt>.
12051<tt><i>INVOKE</i>(f, w1, w2, ..., wN)</tt> (20.7.2 [func.require]) shall be a valid expression for
12052some values <tt>w1, w2, ... , wN,</tt> where <tt>N == sizeof...(Args)</tt>.
12053</p>
12054<p>
12055-5- <i>Effects:</i> Constructs an object of type <tt>thread</tt>
12056<del>and executes <tt><i>INVOKE</i>(f, t1, t2, ..., tN)</tt> in a new
12057thread of execution, where <tt>t1, t2, ..., tN</tt> are the values in <tt>args...</tt></del>.
12058<ins>Constructs
12059the following objects:</ins>
12060</p>
12061<blockquote><pre><ins>typename decay&lt;F&gt;::type g(std::forward&lt;F&gt;(f));</ins>
12062<ins>tuple&lt;typename decay&lt;Args&gt;::type...&gt; w(std::forward&lt;Args&gt;(args)...);</ins>
12063</pre></blockquote>
12064<p>
12065<ins>and executes <tt><i>INVOKE</i>(g, wi...)</tt> in a new thread of execution.
12066These objects shall be destroyed when the new thread of execution completes.</ins>
12067Any return value from <tt>g</tt> is ignored.
12068<del>If <tt>f</tt> terminates with an uncaught exception, <tt>std::terminate()</tt> shall be called.</del>
12069<ins>If the evaluation of <tt><i>INVOKE</i>(g,  wi...)</tt> terminates
12070with an uncaught exception, <tt>std::terminate()</tt> shall be called [<i>Note:</i>
12071<tt>std::terminate()</tt> could be called before entering <tt>g</tt>. -- <i>end note</i>]. Any
12072exception thrown before the evaluation of <tt><i>INVOKE</i></tt> has started shall be
12073catchable in the calling thread.</ins>
12074</p>
12075<p>
12076-6- <i>Synchronization:</i> The invocation of the constructor <i>happens before</i> the
12077invocation of <del><tt>f</tt></del> <ins><tt>g</tt></ins>.
12078</p>
12079</blockquote>
12080
12081</blockquote>
12082</blockquote>
12083
12084
12085<p><b>Proposed resolution:</b></p>
12086<p>
12087Modify the class definition of <tt>std::thread</tt> in 30.3.1 [thread.thread.class] to remove the
12088following signature:
12089</p>
12090
12091<blockquote><pre><del>template&lt;class F&gt; explicit thread(F f);</del>
12092template&lt;class F, class ... Args&gt; <ins>explicit</ins> thread(F&amp;&amp; f, Args&amp;&amp; ... args);
12093</pre></blockquote>
12094
12095<p>
12096Modify 30.3.1.2 [thread.thread.constr] to replace the constructors prior to paragraph 4 with
12097the single constructor as above. Replace paragraph 4 - 6 with the
12098following:
12099</p>
12100
12101<blockquote>
12102<p>
12103-4- <i>Requires:</i> <tt>F</tt> and each <tt>Ti</tt> in <tt>Args</tt>
12104shall be <del><tt>CopyConstructible</tt> if an lvalue and
12105otherwise</del> <tt>MoveConstructible</tt>. <tt><i>INVOKE</i>(f, w1, w2,
12106..., wN)</tt> (20.7.2 [func.require]) shall be a valid expression
12107for some values <tt>w1, w2, ... , wN,</tt> where <tt>N ==
12108sizeof...(Args)</tt>.
12109</p>
12110
12111<p>
12112-5- <i>Effects:</i> Constructs an object of type <tt>thread</tt> <del>and executes
12113<tt>INVOKE(f, t1, t2, ..., tN)</tt> in a new thread of execution, where
12114<tt>t1, t2, ..., tN</tt> are the values in <tt>args...</tt></del>. 
12115<ins>Given a function as follows:</ins>
12116<del>Any return
12117value from <tt>f</tt> is ignored. If <tt>f</tt> terminates with an
12118uncaught exception, <tt>std::terminate()</tt> shall be called.</del>
12119</p>
12120
12121<blockquote><pre><ins>
12122template&lt;typename T&gt; typename decay&lt;T&gt;::type decay_copy(T&amp;&amp; v)
12123    { return std::forward&lt;T&gt;(v); }
12124</ins></pre></blockquote>
12125
12126<p><ins>
12127The new thread of execution executes <tt>INVOKE(decay_copy(f),
12128decay_copy(args)...)</tt> with the calls to <tt>decay_copy()</tt> being evaluated in
12129the constructing thread. Any return value from this invocation is
12130ignored. [<i>Note:</i> this implies any exceptions not thrown from the
12131invocation of the copy of <tt>f</tt> will be thrown in the constructing thread,
12132not the new thread. &#8212; <i>end note</i>].
12133</ins></p>
12134
12135<p>
12136-6- <i>Synchronization:</i> The invocation of the constructor <i>happens before</i> the
12137invocation of <ins>copy of</ins> <tt>f</tt>.
12138</p>
12139</blockquote>
12140
12141
12142
12143
12144
12145
12146<hr>
12147<h3><a name="932"></a>932. <tt>unique_ptr(pointer p)</tt> for pointer deleter types</h3>
12148<p><b>Section:</b> 20.8.14.2.1 [unique.ptr.single.ctor] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
12149 <b>Submitter:</b> Howard Hinnant <b>Opened:</b> 2008-11-26  <b>Last modified:</b> 2009-10-22</p>
12150<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#unique.ptr.single.ctor">active issues</a> in [unique.ptr.single.ctor].</p>
12151<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#unique.ptr.single.ctor">issues</a> in [unique.ptr.single.ctor].</p>
12152<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
12153<p><b>Discussion:</b></p>
12154
12155<p><b>Addresses US 79</b></p>
12156
12157<p>
1215820.8.14.2.1 [unique.ptr.single.ctor]/5 no longer requires for <tt>D</tt>
12159not to be a pointer type.  I believe this restriction was accidently removed
12160when we relaxed the completeness reuqirements on <tt>T</tt>. The restriction
12161needs to be put back in.  Otherwise we have a run time failure that could
12162have been caught at compile time:
12163</p>
12164
12165<blockquote><pre>{
12166unique_ptr&lt;int, void(*)(void*)&gt; p1(malloc(sizeof(int)));  <font color="#c80000">// should not compile</font>
12167}  <font color="#c80000">// p1.~unique_ptr() dereferences a null function pointer</font>
12168unique_ptr&lt;int, void(*)(void*)&gt; p2(malloc(sizeof(int)), free);  <font color="#c80000">// ok</font>
12169</pre></blockquote>
12170
12171<p><i>[
12172Post Summit:
12173]</i></p>
12174
12175
12176<blockquote>
12177Recommend Tentatively Ready.
12178</blockquote>
12179
12180<p><i>[
121812009-07 Frankfurt
12182]</i></p>
12183
12184
12185<blockquote>
12186Moved from Tentatively Ready to Open only because the wording needs to be
12187improved for enable_if type constraining, possibly following Robert's
12188formula.
12189</blockquote>
12190
12191<p><i>[
121922009-07 Frankfurt:
12193]</i></p>
12194
12195
12196<blockquote>
12197<p>
12198We need to consider whether some requirements in the Requires paragraphs
12199of [unique.ptr] should instead be Remarks.
12200</p>
12201<p>
12202Leave Open. Howard to provide wording, and possibly demonstrate how this
12203can be implemented using enable_if.
12204</p>
12205</blockquote>
12206
12207<p><i>[
122082009-07-27 Howard adds:
12209]</i></p>
12210
12211
12212<blockquote>
12213<p>
12214The two constructors to which this issue applies are not easily constrained
12215with <tt>enable_if</tt> as they are not templated:
12216</p>
12217
12218<blockquote><pre>unique_ptr();
12219explicit unique_ptr(pointer p);
12220</pre></blockquote>
12221
12222<p>
12223To "SFINAE" these constructors away would take heroic effort such as specializing
12224the entire <tt>unique_ptr</tt> class template on pointer deleter types.  There
12225is insufficient motivation for such heroics.  Here is the expected and
12226reasonable implementation for these constructors:
12227</p>
12228
12229<blockquote><pre>unique_ptr()
12230    : ptr_(pointer())
12231    {
12232        static_assert(!is_pointer&lt;deleter_type&gt;::value,
12233            "unique_ptr constructed with null function pointer deleter");
12234    }
12235explicit unique_ptr(pointer p)
12236    : ptr_(p)
12237    {
12238        static_assert(!is_pointer&lt;deleter_type&gt;::value,
12239            "unique_ptr constructed with null function pointer deleter");
12240    }
12241</pre></blockquote>
12242
12243<p>
12244I.e. just use <tt>static_assert</tt> to verify that the constructor is not
12245instantiated with a function pointer for a deleter.  The compiler will automatically
12246take care of issuing a diagnostic if the deleter is a reference type (uninitialized
12247reference error).
12248</p>
12249
12250<p>
12251In keeping with our discussions in Frankfurt, I'm moving this requirement on
12252the implementation from the Requires paragraph to a Remarks paragraph.
12253</p>
12254
12255</blockquote>
12256
12257<p><i>[
122582009-08-17 Daniel adds:
12259]</i></p>
12260
12261
12262<blockquote>
12263<p>
12264It is insufficient to require a diagnostic. This doesn't imply an
12265ill-formed program
12266as of 1.3.3 [defns.diagnostic] (a typical alternative would be a compiler
12267warning), but
12268exactly that seems to be the intend. I suggest to use the following
12269remark instead:
12270</p>
12271
12272<blockquote>
12273<i>Remarks:</i> The program shall be ill-formed if this constructor is
12274instantiated when <tt>D</tt> is a pointer type or reference type.
12275</blockquote>
12276
12277<p>
12278Via the general standard rules of 1.4 [intro.compliance] the "diagnostic
12279required" is implied.
12280</p>
12281
12282</blockquote>
12283
12284<p><i>[
122852009-10 Santa Cruz:
12286]</i></p>
12287
12288
12289<blockquote>
12290Moved to Ready.
12291</blockquote>
12292
12293
12294
12295<p><b>Proposed resolution:</b></p>
12296<p>
12297Change the description of the default constructor in 20.8.14.2.1 [unique.ptr.single.ctor]:
12298</p>
12299
12300<blockquote><pre>unique_ptr();
12301</pre>
12302<blockquote>
12303<p>
12304-1- <i>Requires:</i> <tt>D</tt> shall be default constructible, and that construction
12305shall not throw an exception. <del><tt>D</tt> shall 
12306not be a reference type or pointer type (diagnostic required).</del>
12307</p>
12308<p>...</p>
12309<p><ins>
12310<i>Remarks:</i> The program shall be ill-formed if this constructor is
12311instantiated when <tt>D</tt> is a pointer type or reference type.
12312
12313</ins></p>
12314</blockquote>
12315</blockquote>
12316
12317<p>
12318Add  after 20.8.14.2.1 [unique.ptr.single.ctor]/8:
12319</p>
12320
12321<blockquote><pre>unique_ptr(pointer p);
12322</pre>
12323<blockquote>
12324<p>...</p>
12325<p><ins>
12326<i>Remarks:</i> The program shall be ill-formed if this constructor is
12327instantiated when <tt>D</tt> is a pointer type or reference type.
12328
12329</ins></p>
12330</blockquote>
12331</blockquote>
12332
12333
12334
12335
12336
12337<hr>
12338<h3><a name="939"></a>939. Problem with <tt>std::identity</tt> and reference-to-temporaries</h3>
12339<p><b>Section:</b> 20.3.3 [forward] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
12340 <b>Submitter:</b> Alisdair Meredith <b>Opened:</b> 2008-12-11  <b>Last modified:</b> 2009-10-29</p>
12341<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#forward">issues</a> in [forward].</p>
12342<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
12343<p><b>Discussion:</b></p>
12344<p>
12345<tt>std::identity</tt> takes an argument of type <tt>T const &amp;</tt>
12346and returns a result of <tt>T const &amp;</tt>.
12347</p>
12348<p>
12349Unfortunately, this signature will accept a value of type other than <tt>T</tt> that
12350is convertible-to-<tt>T</tt>, and then return a reference to the dead temporary.  The
12351constraint in the concepts version simply protects against returning
12352reference-to-<tt>void</tt>.
12353</p>
12354<p>
12355Solutions:
12356</p>
12357<blockquote>
12358<p>
12359i/  Return-by-value, potentially slicing bases and rejecting non-copyable
12360types
12361</p>
12362<p>
12363ii/ Provide an additional overload:
12364</p>
12365<blockquote><pre>template&lt; typename T &gt;
12366template operator( U &amp; ) = delete;
12367</pre></blockquote>
12368<p>
12369This seems closer on intent, but moves beyond the original motivation for
12370the operator, which is compatibility with existing (non-standard)
12371implementations.
12372</p>
12373<p>
12374iii/ Remove the <tt>operator()</tt> overload.  This restores the original definition
12375of the <tt>identity</tt>, although now effectively a type_trait rather than part of
12376the perfect forwarding protocol.
12377</p>
12378<p>
12379iv/ Remove <tt>std::identity</tt> completely; its original reason to exist is
12380replaced with the <tt>IdentityOf</tt> concept.
12381</p>
12382</blockquote>
12383<p>
12384My own preference is somewhere between (ii) and (iii) - although I stumbled
12385over the issue with a specific application hoping for resolution (i)!
12386</p>
12387
12388<p><i>[
12389Batavia (2009-05):
12390]</i></p>
12391
12392<blockquote>
12393<p>
12394We dislike options i and iii, and option ii seems like overkill.
12395If we remove it (option iv), implementers can still provide it under a
12396different name.
12397</p>
12398<p>
12399Move to Open pending wording (from Alisdair) for option iv.
12400</p>
12401</blockquote>
12402
12403<p><i>[
124042009-05-23 Alisdair provided wording for option iv.
12405]</i></p>
12406
12407
12408<p><i>[
124092009-07-20 Alisdair adds:
12410]</i></p>
12411
12412
12413<blockquote>
12414<p>
12415I'm not sure why this issue was not discussed at Frankfurt (or I missed
12416the discussion) but the rationale is now fundamentally flawed.  With the
12417removal of concepts, <tt>std::identity</tt> again becomes an important library
12418type so we cannot simply remove it.
12419</p>
12420<p>
12421At that point, we need to pick one of the other suggested resolutions,
12422but have no guidance at the moment.
12423</p>
12424</blockquote>
12425
12426<p><i>[
124272009-07-20 Howard adds:
12428]</i></p>
12429
12430
12431<blockquote>
12432<p>
12433I believe the rationale for not addressing this issue in Frankfurt was that it did
12434not address a national body comment.
12435</p>
12436<p>
12437I also believe that removal of <tt>identity</tt> is still a practical option as
12438my latest reformulation of <tt>forward</tt>, which is due to comments suggested
12439at Summit, no longer uses <tt>identity</tt>. :-)
12440</p>
12441
12442<blockquote><pre>template &lt;class T, class U,
12443    class = typename enable_if
12444            &lt;
12445                !is_lvalue_reference&lt;T&gt;::value || 
12446                 is_lvalue_reference&lt;T&gt;::value &amp;&amp;
12447                 is_lvalue_reference&lt;U&gt;::value
12448            &gt;::type,
12449    class = typename enable_if
12450            &lt;
12451                is_same&lt;typename remove_all&lt;T&gt;::type,
12452                        typename remove_all&lt;U&gt;::type&gt;::value
12453            &gt;::type&gt;
12454inline
12455T&amp;&amp;
12456forward(U&amp;&amp; t)
12457{
12458    return static_cast&lt;T&amp;&amp;&gt;(t);
12459
12460}
12461</pre>
12462
12463<p><i>[
12464The above code assumes acceptance of <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1120">1120</a> for the definition of
12465<tt>remove_all</tt>.  This is just to make the syntax a little more palatable.
12466Without this trait the above is still very implementable.
12467]</i></p>
12468
12469
12470</blockquote>
12471
12472<p>
12473Paper with rationale is on the way ... <i>really</i>, I promise this time! ;-)
12474</p>
12475</blockquote>
12476
12477<p><i>[
124782009-07-30 Daniel adds:  See <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#823">823</a> for an alternative resolution.
12479]</i></p>
12480
12481
12482<p><i>[
124832009-10 Santa Cruz:
12484]</i></p>
12485
12486
12487<blockquote>
12488Move to Ready. Howard will update proposed wording to reflect current draft.
12489</blockquote>
12490
12491
12492
12493<p><b>Proposed resolution:</b></p>
12494<p>
12495Strike from 20.3 [utility]:
12496</p>
12497
12498<blockquote><pre><del>template &lt;class T&gt; struct identity;</del>
12499</pre></blockquote>
12500
12501<p>
12502Remove from 20.3.3 [forward]:
12503</p>
12504
12505<blockquote>
12506<pre><del>template &lt;class T&gt; struct identity {
12507  typedef T type;
12508
12509  const T&amp; operator()(const T&amp; x) const;
12510};</del>
12511
12512<del>const T&amp; operator()(const T&amp; x) const;</del>
12513</pre>
12514<blockquote>
12515<del>-2-  <i>Returns:</i> <tt>x</tt></del>
12516</blockquote>
12517</blockquote>
12518
12519
12520
12521
12522
12523
12524<hr>
12525<h3><a name="940"></a>940. <tt>std::distance</tt></h3>
12526<p><b>Section:</b> 24.4.4 [iterator.operations] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
12527 <b>Submitter:</b> Thomas <b>Opened:</b> 2008-12-14  <b>Last modified:</b> 2009-10-22</p>
12528<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#iterator.operations">active issues</a> in [iterator.operations].</p>
12529<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#iterator.operations">issues</a> in [iterator.operations].</p>
12530<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
12531<p><b>Discussion:</b></p>
12532
12533<p><b>Addresses UK 270</b></p>
12534
12535<p>
12536Regarding the <tt>std::distance</tt> - function, 24.4.4 [iterator.operations]
12537/ 4 says:
12538</p>
12539<blockquote>
12540Returns the
12541number of increments or decrements needed to get from first to last.
12542</blockquote>
12543<p>
12544This sentence is completely silent about the sign of the return value.
1254524.4.4 [iterator.operations] / 1 gives more information about the
12546underlying operations, but
12547again no inferences about the sign can be made.
12548Strictly speaking, that is taking that sentence literally, I think this
12549sentence even implies a positive return value in all cases, as the
12550number of increments or decrements is clearly a ratio scale variable,
12551with a natural zero bound.
12552</p>
12553<p>
12554Practically speaking, my implementations did what common sense and
12555knowledge based on pointer arithmetic forecasts, namely a positive sign
12556for increments (that is, going from <tt>first</tt> to <tt>last</tt> by <tt>operator++</tt>), and a
12557negative sign for decrements (going from <tt>first</tt> to <tt>last</tt> by <tt>operator--</tt>).
12558</p>
12559<p>
12560Here are my two questions:
12561</p>
12562<p>
12563First, is that paragraph supposed to be interpreted in the way what I
12564called 'common sense', that is negative sign for decrements ? I am
12565fairly sure that's the supposed behavior, but a double-check here in
12566this group can't hurt.
12567</p>
12568<p>
12569Second, is the present wording (2003 standard version - no idea about
12570the draft for the upcoming standard) worth an edit to make it a bit more
12571sensible, to mention the sign of the return value explicitly ?
12572</p>
12573
12574<p><i>[
12575Daniel adds:
12576]</i></p>
12577
12578
12579<blockquote>
12580<p>
12581My first thought was that resolution <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#204">204</a> would already cover the
12582issue report, but it seems that current normative wording is in
12583contradiction to that resolution:
12584</p>
12585
12586<p>
12587Referring to
12588<a href="" ref="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2798.pdf">N2798</a>,
1258924.4.4 [iterator.operations]/ p.4 says:
12590</p>
12591
12592<blockquote>
12593<i>Effects:</i> Returns the number of increments or decrements needed to get
12594from <tt>first</tt> to <tt>last</tt>.
12595</blockquote>
12596
12597<p>
12598IMO the part " or decrements" is in contradiction to p. 5 which says
12599</p>
12600
12601<blockquote>
12602<i>Requires:</i> <tt>last</tt> shall be reachable from <tt>first</tt>.
12603</blockquote>
12604
12605<p>
12606because "reachable" is defined in X [iterator.concepts]/7 as
12607</p>
12608
12609<blockquote>
12610An iterator <tt>j</tt> is called reachable from an iterator <tt>i</tt> if and only if
12611there is a finite
12612sequence of applications of the expression <tt>++i</tt> that makes <tt>i == j</tt>.[..]
12613</blockquote>
12614
12615<p>
12616Here is wording that would be consistent with this definition of "reachable":
12617</p>
12618
12619<p>
12620Change 24.4.4 [iterator.operations] p4 as follows:
12621</p>
12622
12623<blockquote>
12624<i>Effects:</i> Returns the number of increments <del>or decrements</del>
12625needed to get from <tt>first</tt> to <tt>last</tt>.
12626</blockquote>
12627
12628</blockquote>
12629
12630<p>
12631Thomas adds more discussion and an alternative view point
12632<a href="http://groups.google.com/group/comp.std.c++/browse_thread/thread/e8e46dcda0a5d797#">here</a>.
12633</p>
12634
12635<p><i>[
12636Summit:
12637]</i></p>
12638
12639
12640<blockquote>
12641The proposed wording below was verbally agreed to.  Howard provided.
12642</blockquote>
12643
12644<p><i>[
12645Batavia (2009-05):
12646]</i></p>
12647
12648<blockquote>
12649<p>
12650Pete reports that a recent similar change has been made
12651for the <tt>advance()</tt> function.
12652</p>
12653<p>
12654We agree with the proposed resolution.
12655Move to Tentatively Ready.
12656</p>
12657</blockquote>
12658
12659<p><i>[
126602009-07 Frankfurt
12661]</i></p>
12662
12663
12664<blockquote>
12665Moved from Tentatively Ready to Open only because the wording needs to be
12666tweaked for concepts removal.
12667</blockquote>
12668
12669<p><i>[
126702009-07 Frankfurt:
12671]</i></p>
12672
12673
12674<blockquote>
12675Leave Open pending arrival of a post-Concepts WD.
12676</blockquote>
12677
12678<p><i>[
126792009-10-14 Daniel provided de-conceptified wording.
12680]</i></p>
12681
12682
12683<p><i>[
126842009-10 Santa Cruz:
12685]</i></p>
12686
12687
12688<blockquote>
12689Move to Ready, replacing the Effects clause in the proposed wording with
12690"If InputIterator meets the requirements of random access iterator then
12691returns (last - first), otherwise returns the number of increments
12692needed to get from first to list.".
12693</blockquote>
12694
12695
12696
12697<p><b>Proposed resolution:</b></p>
12698<ol>
12699<li>
12700<p>
12701Change 24.2.5 [random.access.iterators], Table 105 as indicated [This change is not
12702essential but it simplifies the specification] for the row with
12703expression "<tt>b - a</tt>"
12704and the column Operational semantics:
12705</p>
12706
12707<blockquote><pre><del>(a &lt; b) ? </del>distance(a,b)
12708<del>: -distance(b,a)</del>
12709</pre></blockquote>
12710</li>
12711
12712<li>
12713<p>
12714Change 24.4.4 [iterator.operations]/4+5 as indicated:
12715</p>
12716
12717<blockquote><pre>template&lt;class InputIterator&gt;
12718  typename iterator_traits&lt;InputIterator&gt;::difference_type
12719    distance(InputIterator first, InputIterator last);
12720</pre>
12721<blockquote>
12722<p>
127234 <i>Effects:</i> <ins>If <tt>InputIterator</tt> meets the requirements
12724of random access iterator then returns <tt>(last - first)</tt>,
12725otherwise</ins> <del>R</del><ins>r</ins>eturns the number of increments
12726<del>or decrements</del> needed to get from <tt>first</tt> to
12727<tt>last</tt>.
12728</p>
12729
12730<p>
127315 <i>Requires:</i> <ins>If <tt>InputIterator</tt> meets the requirements
12732of random access iterator then <tt>last</tt> shall be reachable from
12733<tt>first</tt> or <tt>first</tt> shall be reachable from <tt>last</tt>,
12734otherwise</ins> <tt>last</tt> shall be reachable from <tt>first</tt>.
12735</p>
12736</blockquote>
12737</blockquote>
12738</li>
12739</ol>
12740
12741
12742
12743
12744
12745
12746
12747
12748
12749<hr>
12750<h3><a name="950"></a>950. unique_ptr converting ctor shouldn't accept array form</h3>
12751<p><b>Section:</b> 20.8.14.2.1 [unique.ptr.single.ctor] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
12752 <b>Submitter:</b> Howard Hinnant <b>Opened:</b> 2009-01-07  <b>Last modified:</b> 2009-10-21</p>
12753<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#unique.ptr.single.ctor">active issues</a> in [unique.ptr.single.ctor].</p>
12754<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#unique.ptr.single.ctor">issues</a> in [unique.ptr.single.ctor].</p>
12755<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
12756<p><b>Discussion:</b></p>
12757<p>
12758<tt>unique_ptr</tt>'s of array type should not convert to
12759<tt>unique_ptr</tt>'s which do not have an array type.
12760</p>
12761
12762<blockquote><pre>struct Deleter
12763{
12764   void operator()(void*) {}
12765};
12766
12767int main()
12768{
12769   unique_ptr&lt;int[], Deleter&gt; s;
12770   unique_ptr&lt;int, Deleter&gt; s2(std::move(s));  <font color="#c80000">// should not compile</font>
12771}
12772</pre></blockquote>
12773
12774<p><i>[
12775Post Summit:
12776]</i></p>
12777
12778
12779<blockquote>
12780<p>
12781Walter: Does the "diagnostic required" apply to both arms of the "and"?
12782</p>
12783<p>
12784Tom Plum: suggest to break into several sentences
12785</p>
12786<p>
12787Walter: suggest "comma" before the "and" in both places
12788</p>
12789<p>
12790Recommend Review.
12791</p>
12792</blockquote>
12793
12794<p><i>[
12795Batavia (2009-05):
12796]</i></p>
12797
12798<blockquote>
12799The post-Summit comments have been applied to the proposed resolution.
12800We now agree with the proposed resolution.
12801Move to Tentatively Ready.
12802</blockquote>
12803
12804<p><i>[
128052009-07 Frankfurt
12806]</i></p>
12807
12808
12809<blockquote>
12810Moved from Tentatively Ready to Open only because the wording needs to be
12811improved for enable_if type constraining, possibly following Robert's
12812formula.
12813</blockquote>
12814
12815<p><i>[
128162009-08-01 Howard updates wording and sets to Review.
12817]</i></p>
12818
12819
12820<p><i>[
128212009-10 Santa Cruz:
12822]</i></p>
12823
12824
12825<blockquote>
12826Move to Ready.
12827</blockquote>
12828
12829
12830
12831<p><b>Proposed resolution:</b></p>
12832<p>
12833Change 20.8.14.2.1 [unique.ptr.single.ctor]:
12834</p>
12835
12836<blockquote>
12837<pre>template &lt;class U, class E&gt; unique_ptr(unique_ptr&lt;U, E&gt;&amp;&amp; u);
12838</pre>
12839<blockquote>
12840<p>
12841-20- <i>Requires:</i> If <tt>D</tt> is not a reference type,
12842construction of the deleter <tt>D</tt> from an rvalue of type <tt>E</tt>
12843shall be well formed and shall not throw an exception. <del>If <tt>D</tt> is
12844a reference type, then <tt>E</tt> shall be the same type as <tt>D</tt>
12845(diagnostic required). <tt>unique_ptr&lt;U, E&gt;::pointer</tt> shall be
12846implicitly convertible to <tt>pointer</tt>. [<i>Note:</i> These requirements
12847imply that <tt>T</tt> and <tt>U</tt> are complete types. &#8212; <i>end note</i>]</del>
12848</p>
12849
12850<p><ins>
12851<i>Remarks:</i> If <tt>D</tt> is
12852a reference type, then <tt>E</tt> shall be the same type as <tt>D</tt>, else this
12853constructor shall not participate in overload resolution. <tt>unique_ptr&lt;U, E&gt;::pointer</tt> shall be
12854implicitly convertible to <tt>pointer</tt>, else this
12855constructor shall not participate in overload resolution. <tt>U</tt> shall not be
12856an array type, else this
12857constructor shall not participate in overload resolution. [<i>Note:</i> These requirements
12858imply that <tt>T</tt> and <tt>U</tt> are complete types. &#8212; <i>end note</i>]
12859</ins></p>
12860
12861</blockquote>
12862</blockquote>
12863
12864<p>
12865Change 20.8.14.2.3 [unique.ptr.single.asgn]:
12866</p>
12867
12868<blockquote>
12869<pre>template &lt;class U, class E&gt; unique_ptr&amp; operator=(unique_ptr&lt;U, E&gt;&amp;&amp; u);
12870</pre>
12871<blockquote>
12872<p>
12873-6- <i>Requires:</i> Assignment of the deleter <tt>D</tt> from an rvalue
12874<tt>D</tt> shall not throw an exception. <del><tt>unique_ptr&lt;U,
12875E&gt;::pointer</tt> shall be implicitly convertible to <tt>pointer</tt>.
12876[<i>Note:</i> These requirements imply that <tt>T</tt> and <tt>U</tt>
12877are complete types. &#8212; <i>end note</i>]</del>
12878</p>
12879
12880<p><ins>
12881<i>Remarks:</i> <tt>unique_ptr&lt;U,
12882E&gt;::pointer</tt> shall be implicitly convertible to <tt>pointer</tt>, else this
12883operator shall not participate in overload resolution.
12884<tt>U</tt> shall not be an array type, else this
12885operator shall not participate in overload resolution.
12886[<i>Note:</i> These requirements imply that <tt>T</tt> and <tt>U</tt>
12887are complete types. &#8212; <i>end note</i>]
12888</ins></p>
12889
12890</blockquote>
12891</blockquote>
12892
12893
12894
12895
12896
12897
12898<hr>
12899<h3><a name="951"></a>951. Various threading bugs #1</h3>
12900<p><b>Section:</b> 20.9.2.1 [time.traits.is_fp] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
12901 <b>Submitter:</b> Pete Becker <b>Opened:</b> 2009-01-07  <b>Last modified:</b> 2009-10-23</p>
12902<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
12903<p><b>Discussion:</b></p>
12904
12905<p>
12906Related to <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#953">953</a>.
12907</p>
12908
12909<p>
1291020.9.2.1 [time.traits.is_fp] says that the type <tt>Rep</tt> "is
12911assumed to be ... a class emulating an integral type." What are the
12912requirements for such a type?
12913</p>
12914<p><i>[
129152009-05-10 Howard adds:
12916]</i></p>
12917
12918
12919<blockquote>
12920<tt>IntegralLike</tt>.
12921</blockquote>
12922
12923<p><i>[
12924Batavia (2009-05):
12925]</i></p>
12926
12927<blockquote>
12928<p>
12929As with issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#953">953</a>,
12930we recommend this issue be addressed in the context of providing concepts for the entire <tt>thread</tt> header.
12931</p>
12932<p>
12933We look forward to proposed wording.
12934</p>
12935<p>
12936Move to Open.
12937</p>
12938</blockquote>
12939
12940<p><i>[
129412009-08-01 Howard adds:
12942]</i></p>
12943
12944
12945<blockquote>
12946<p>
12947I have surveyed all clauses of 20.9.2.2 [time.traits.duration_values],
1294820.9.2.3 [time.traits.specializations] and 20.9.3 [time.duration].
12949I can not find any clause which involves the use of a <tt>duration::rep</tt> type
12950where the requirements on the <tt>rep</tt> type are not clearly spelled out.
12951These requirements were carefully crafted to allow any arithmetic type, or
12952any user-defined type emulating an arithmetic type.
12953</p>
12954
12955<p>
12956Indeed, <tt>treat_as_floating_point</tt>
12957becomes completely superfluous if <tt>duration::rep</tt> can never be a class type.
12958</p>
12959
12960<p>
12961There will be some <tt>Rep</tt> types which will not meet the requirements of
12962<em>every</em> <tt>duration</tt> operation.  This is no different than the fact
12963that <tt>vector&lt;T&gt;</tt> can easily be used for types <tt>T</tt> which are
12964not <tt>DefaultConstructible</tt>, even though some members of <tt>vector&lt;T&gt;</tt>
12965require <tt>T</tt> to be <tt>DefaultConstructible</tt>.  This is why the requirements
12966on <tt>Rep</tt> are specified for each operation individually.
12967</p>
12968
12969<p>
12970In 20.9.2.1 [time.traits.is_fp] p1:
12971</p>
12972
12973<blockquote><pre>template &lt;class Rep&gt; struct treat_as_floating_point 
12974  : is_floating_point&lt;Rep&gt; { };
12975</pre>
12976
12977<blockquote>
12978The <tt>duration</tt> template uses the <tt>treat_as_floating_point</tt> trait to help
12979determine if a <tt>duration</tt> object can be converted to another <tt>duration</tt>
12980with a different tick period. If <tt>treat_as_floating_point&lt;Rep&gt;::value</tt> is
12981<tt>true</tt>, then <tt>Rep</tt> is a floating-point type and implicit conversions are
12982allowed among <tt>duration</tt>s. Otherwise, the implicit convertibility depends
12983on the tick periods of the <tt>duration</tt>s. If <tt>Rep</tt> is <u>a class type which
12984emulates a floating-point type</u>, the author of <tt>Rep</tt> can specialize
12985<tt>treat_as_floating_point</tt> so that <tt>duration</tt> will treat this <tt>Rep</tt> as if it
12986were a floating-point type. Otherwise <tt>Rep</tt> is assumed to be an integral
12987type or <u>a class emulating an integral type</u>.
12988</blockquote>
12989</blockquote>
12990
12991<p>
12992The phrases "a class type which emulates a floating-point type" and
12993"a class emulating an integral type" are clarifying phrases which refer to
12994the summation of all the requirements on the <tt>Rep</tt> type specified in
12995detail elsewhere (and <em>should not</em> be repeated here).
12996</p>
12997
12998<p>
12999This specification has been implemented, now multiple times, and the experience
13000has been favorable.  The current specification clearly specifies the requirements
13001at each point of use (though I'd be happy to fix any place I may have missed,
13002but none has been pointed out).
13003</p>
13004
13005<p>
13006I am amenable to improved wording of this paragraph (and any others), but do not have any
13007suggestions for improved wording at this time.  I am <em>strongly</em> opposed to
13008changes which would significantly alter the semantics of the
13009specification under 20.9 [time] without firmly grounded and
13010documented rationale, example implementation, testing, and user
13011experience which relates a positive experience.
13012</p>
13013
13014<p>
13015I recommend NAD unless someone wants to produce some clarifying wording.
13016</p>
13017</blockquote>
13018
13019<p><i>[
130202009-10 Santa Cruz:
13021]</i></p>
13022
13023
13024<blockquote>
13025Stefanus to provide wording to turn this into a note.
13026</blockquote>
13027
13028
13029
13030<p><b>Proposed resolution:</b></p>
13031<p>
13032</p>
13033
13034
13035
13036
13037
13038<hr>
13039<h3><a name="953"></a>953. Various threading bugs #3</h3>
13040<p><b>Section:</b> 20.9.1 [time.clock.req] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
13041 <b>Submitter:</b> Pete Becker <b>Opened:</b> 2009-01-07  <b>Last modified:</b> 2009-10-23</p>
13042<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#time.clock.req">active issues</a> in [time.clock.req].</p>
13043<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#time.clock.req">issues</a> in [time.clock.req].</p>
13044<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
13045<p><b>Discussion:</b></p>
13046
13047<p>
13048Related to <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#951">951</a>.
13049</p>
13050
13051<p>
1305220.9.1 [time.clock.req] says that a clock's <tt>rep</tt> member is "an
13053arithmetic type or a class emulating an arithmetic type." What are the
13054requirements for such a type?
13055</p>
13056
13057<p><i>[
130582009-05-10 Howard adds:
13059]</i></p>
13060
13061
13062<blockquote>
13063This wording was aimed directly at the <tt>ArithmeticLike</tt> concept.
13064</blockquote>
13065
13066<p><i>[
13067Batavia (2009-05):
13068]</i></p>
13069
13070<blockquote>
13071<p>
13072We recommend this issue be addressed in the context of providing concepts
13073for the entire <tt>thread</tt> header.
13074</p>
13075<p>
13076May resolve for now by specifying arithmetic types,
13077and in future change to <tt>ArithmeticLike</tt>.
13078However, Alisdair believes this is not feasible.
13079</p>
13080<p>
13081Bill disagrees.
13082</p>
13083<p>
13084We look forward to proposed wording.  Move to Open.
13085</p>
13086</blockquote>
13087
13088<p><i>[
130892009-08-01 Howard adds:
13090]</i></p>
13091
13092
13093<blockquote>
13094See commented dated 2009-08-01 in <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#951">951</a>.
13095</blockquote>
13096
13097<p><i>[
130982009-10 Santa Cruz:
13099]</i></p>
13100
13101
13102<blockquote>
13103Stefanus to provide wording to turn this into a note.
13104</blockquote>
13105
13106
13107
13108<p><b>Proposed resolution:</b></p>
13109<p>
13110</p>
13111
13112
13113
13114
13115
13116<hr>
13117<h3><a name="954"></a>954. Various threading bugs #4</h3>
13118<p><b>Section:</b> 20.9.1 [time.clock.req] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
13119 <b>Submitter:</b> Pete Becker <b>Opened:</b> 2009-01-07  <b>Last modified:</b> 2009-10-21</p>
13120<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#time.clock.req">active issues</a> in [time.clock.req].</p>
13121<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#time.clock.req">issues</a> in [time.clock.req].</p>
13122<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
13123<p><b>Discussion:</b></p>
13124<p>
13125Table 55 -- Clock Requirements (in 20.9.1 [time.clock.req])
13126</p>
13127
13128<ol type="a">
13129<li>
13130the requirements for <tt>C1::time_point</tt> require <tt>C1</tt> and <tt>C2</tt>
13131to "refer to the same epoch", but "epoch" is not defined.
13132</li>
13133<li>
13134"Different clocks may share a <tt>time_point</tt> definition if it is
13135valid to compare their <tt>time_point</tt>s by comparing their
13136respective <tt>duration</tt>s." What does "valid" mean here? And, since
13137<tt>C1::rep</tt> is "**THE** representation type of the native
13138<tt>duration</tt> and <tt>time_point</tt>" (emphasis added), there
13139doesn't seem to be much room for some other representation.
13140</li>
13141<li>
13142<tt>C1::is_monotonic</tt> has type "<tt>const bool</tt>". The
13143"<tt>const</tt>" should be removed.
13144</li>
13145<li>
13146<tt>C1::period</tt> has type <tt>ratio</tt>. <tt>ratio</tt> isn't a type, 
13147it's a template. What is the required type?
13148</li>
13149</ol>
13150
13151<p><i>[
131522009-05-10 Howard adds:
13153]</i></p>
13154
13155
13156<ol type="a">
13157<li>
13158<p>
13159"epoch" is purposefully not defined beyond the common English
13160<a href="http://www.dictionary.net/epoch">definition</a>.  The C standard
13161also chose not to define epoch, though POSIX did.  I believe it is a strength
13162of the C standard that epoch is not defined.  When it is known that two <tt>time_point</tt>s
13163refer to the same epoch, then a definition of the epoch is not needed to compare
13164the two <tt>time_point</tt>s, or subtract them.
13165</p>
13166<p>
13167A <tt>time_point</tt> and a <tt>Clock</tt> implicitly refer to an (unspecified) epoch.
13168The <tt>time_point</tt> represents an offset (<tt>duration</tt>) from an epoch.
13169</p>
13170</li>
13171<li>
13172<p>
13173The sentence:
13174</p>
13175<blockquote>
13176Different clocks 
13177may share a <tt>time_point</tt>
13178definition if it is valid to 
13179compare their <tt>time_point</tt>s by 
13180comparing their respective 
13181<tt>duration</tt>s.
13182</blockquote>
13183
13184<p>
13185is redundant and could be removed.  I believe the sentence which follows the above:
13186</p>
13187
13188<blockquote>
13189<tt>C1</tt> and <tt>C2</tt> shall refer to the same epoch.
13190</blockquote>
13191
13192<p>
13193is sufficient.  If two clocks share the same epoch, then by definition, comparing
13194their <tt>time_point</tt>s is valid.
13195</p>
13196</li>
13197<li>
13198<tt>is_monotonic</tt> is meant to never change (be <tt>const</tt>).  It is also
13199desired that this value be usable in compile-time computation and branching.
13200</li>
13201<li>
13202<p>
13203This should probably instead be worded:
13204</p>
13205<blockquote>
13206An instantiation of <tt>ratio</tt>.
13207</blockquote>
13208</li>
13209</ol>
13210
13211<p><i>[
13212Batavia (2009-05):
13213]</i></p>
13214
13215<blockquote>
13216<p>
13217Re (a): It is not clear to us whether "epoch" is a term of art.
13218</p>
13219<p>
13220Re (b), (c), and (d):  We agree with Howard's comments,
13221and would consider adding to (c) a <tt>static constexpr</tt> requirement.
13222</p>
13223<p>
13224Move to Open pending proposed wording.
13225</p>
13226</blockquote>
13227
13228<p><i>[
132292009-05-25 Daniel adds:
13230]</i></p>
13231
13232
13233<blockquote>
13234In regards to (d) I suggest to say "a specialization of ratio" instead of
13235"An instantiation of ratio". This seems to be the better matching standard
13236core language term for this kind of entity.
13237</blockquote>
13238
13239<p><i>[
132402009-05-25 Ganesh adds:
13241]</i></p>
13242
13243
13244<blockquote>
13245<p>
13246Regarding (a), I found this paper on the ISO website using the term "epoch" consistently with the current wording:
13247</p>
13248
13249<p>
13250<a href="http://standards.iso.org/ittf/PubliclyAvailableStandards/C030811e_FILES/MAIN_C030811e/text/ISOIEC_18026E_TEMPORAL_CS.HTM">http://standards.iso.org/ittf/PubliclyAvailableStandards/C030811e_FILES/MAIN_C030811e/text/ISOIEC_18026E_TEMPORAL_CS.HTM</a>
13251</p>
13252<p>
13253which is part of ISO/IEC 18026 "Information technology -- Spatial Reference Model (SRM)".
13254</p>
13255</blockquote>
13256
13257<p><i>[
132582009-08-01 Howard: Moved to Reivew as the wording requested in Batavia has been provided.
13259]</i></p>
13260
13261
13262<p><i>[
132632009-10 Santa Cruz:
13264]</i></p>
13265
13266
13267<blockquote>
13268Move to Ready.
13269</blockquote>
13270
13271
13272
13273<p><b>Proposed resolution:</b></p>
13274<ol type="a">
13275<li>
13276<p>
13277Change 20.9.1 [time.clock.req] p1:
13278</p>
13279<blockquote>
13280-1- A clock is a bundle consisting of a native <tt>duration</tt>, a native <tt>time_point</tt>, and a function <tt>now()</tt> to get the 
13281current <tt>time_point</tt>.  <ins>The origin of the clock's <tt>time_point</tt> is referred to as the clock's <i>epoch</i> as defined in 
13282section 6.3 of ISO/IEC 18026.</ins>
13283A clock shall meet the requirements in Table 45.
13284</blockquote>
13285</li>
13286<li>
13287<p>
13288Remove the sentence from the <tt>time_point</tt> row of the table "Clock Requirements":
13289</p>
13290<table border="1">
13291<caption>Clock requirements</caption>
13292<tbody><tr>
13293<td>
13294<tt>C1::time_point</tt>
13295</td>
13296<td>
13297<tt>chrono::time_point&lt;C1&gt;</tt> or <tt>chrono::time_point&lt;C2, C1::duration&gt;</tt>
13298</td>
13299<td>
13300The native <tt>time_point</tt> type of the clock.
13301<del>Different clocks may share a <tt>time_point</tt> definition if it is valid to compare their <tt>time_point</tt>s by comparing their respective <tt>duration</tt>s.</del>
13302<tt>C1</tt> and <tt>C2</tt> shall refer to the same epoch.
13303</td>
13304</tr>
13305</tbody></table>
13306</li>
13307</ol>
13308<ol start="4" type="a">
13309<li>
13310<p>
13311Change the row starting with <tt>C1::period</tt> of the table "Clock Requirements":
13312</p>
13313<table border="1">
13314<caption>Clock requirements</caption>
13315<tbody><tr>
13316<td>
13317<tt>C1::period</tt>
13318</td>
13319<td>
13320<ins>a specialization of</ins> <tt>ratio</tt>
13321</td>
13322<td>
13323The tick period of the clock in seconds.
13324</td>
13325</tr>
13326</tbody></table>
13327
13328</li>
13329</ol>
13330
13331
13332
13333
13334
13335<hr>
13336<h3><a name="956"></a>956. Various threading bugs #6</h3>
13337<p><b>Section:</b> 20.9.1 [time.clock.req] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
13338 <b>Submitter:</b> Pete Becker <b>Opened:</b> 2009-01-07  <b>Last modified:</b> 2009-10-24</p>
13339<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#time.clock.req">active issues</a> in [time.clock.req].</p>
13340<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#time.clock.req">issues</a> in [time.clock.req].</p>
13341<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
13342<p><b>Discussion:</b></p>
13343<p>
1334420.9.1 [time.clock.req] uses the word "native" in several places,
13345but doesn't define it. What is a "native <tt>duration</tt>"?
13346</p>
13347
13348<p><i>[
133492009-05-10 Howard adds:
13350]</i></p>
13351
13352
13353<blockquote>
13354The standard uses "native" in several places without defining it (e.g.
133552.14.3 [lex.ccon]).  It is meant to mean "that which is defined
13356by the facility", or something along those lines.  In this case it refers
13357to the nested <tt>time_point</tt> and <tt>duration</tt> types of the clock.
13358Better wording is welcome.
13359</blockquote>
13360
13361<p><i>[
13362Batavia (2009-05):
13363]</i></p>
13364
13365<blockquote>
13366Move to Open pending proposed wording from Pete.
13367</blockquote>
13368
13369<p><i>[
133702009-10-23 Pete provides wording:
13371]</i></p>
13372
13373
13374
13375<p><b>Proposed resolution:</b></p>
13376<p>
13377Remove every occurrence of "native" in 20.9.1 [time.clock.req].
13378</p>
13379
13380<p>
13381Add the following sentence at the end of 20.9.1 [time.clock.req]/1:
13382</p>
13383
13384<blockquote>
13385A clock is a bundle consisting of a <del>native</del> <tt>duration</tt>, a <del>native</del>
13386<tt>time_point</tt>, and a function <tt>now()</tt> to get the current <tt>time_point</tt>. A clock
13387shall meet the requirements in Table 55.
13388<ins>The <tt>duration</tt> and <tt>time_point</tt> types have the natural size and resolution
13389suggested by the architecture of the execution environment.</ins>
13390</blockquote>
13391
13392
13393
13394
13395
13396<hr>
13397<h3><a name="957"></a>957. Various threading bugs #7</h3>
13398<p><b>Section:</b> 20.9.5.1 [time.clock.system] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
13399 <b>Submitter:</b> Pete Becker <b>Opened:</b> 2009-01-07  <b>Last modified:</b> 2009-10-21</p>
13400<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#time.clock.system">issues</a> in [time.clock.system].</p>
13401<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
13402<p><b>Discussion:</b></p>
13403<p>
1340420.9.5.1 [time.clock.system]: <tt>to_time_t</tt> is overspecified. It
13405requires truncation, but should allow rounding. For example, suppose a
13406system has a clock that gives times in milliseconds, but <tt>time()</tt> rounds
13407those times to the nearest second. Then <tt>system_clock</tt> can't use any
13408resolution finer than one second, because if it did, truncating times
13409between half a second and a full second would produce the wrong <tt>time_t</tt>
13410value.
13411</p>
13412
13413<p><i>[
13414Post Summit Anthony Williams provided proposed wording.
13415]</i></p>
13416
13417
13418<p><i>[
13419Batavia (2009-05):
13420]</i></p>
13421
13422<blockquote>
13423Move to Review pending input from Howard. and other stakeholders.
13424</blockquote>
13425
13426<p><i>[
134272009-05-23 Howard adds:
13428]</i></p>
13429
13430
13431<blockquote>
13432I am in favor of the wording provided by Anthony.
13433</blockquote>
13434
13435<p><i>[
134362009-10 Santa Cruz:
13437]</i></p>
13438
13439
13440<blockquote>
13441Move to Ready.
13442</blockquote>
13443
13444
13445
13446<p><b>Proposed resolution:</b></p>
13447<p>
13448In 20.9.5.1 [time.clock.system] replace paragraphs 3 and 4 with:
13449</p>
13450
13451<blockquote>
13452<pre>time_t to_time_t(const time_point&amp; t);
13453</pre>
13454<blockquote>
13455-3- <i>Returns:</i> A <tt>time_t</tt> object that represents the same
13456point in time as <tt>t</tt> when both values are <del>truncated</del>
13457<ins>restricted</ins> to the coarser of the precisions of
13458<tt>time_t</tt> and <tt>time_point</tt>. <ins> It is implementation
13459defined whether values are rounded or truncated to the required
13460precision.</ins>
13461</blockquote>
13462
13463<pre>time_point from_time_t(time_t t);
13464</pre>
13465<blockquote>
13466-4- <i>Returns:</i> A <tt>time_point</tt> object that represents the
13467same point in time as <tt>t</tt> when both values are <del>truncated</del>
13468<ins>restricted</ins> to the
13469coarser of the precisions of <tt>time_t</tt> and <tt>time_point</tt>.
13470<ins>It is implementation defined whether values are
13471rounded or truncated to the required precision.</ins>
13472</blockquote>
13473</blockquote>
13474
13475
13476
13477
13478
13479<hr>
13480<h3><a name="959"></a>959. Various threading bugs #9</h3>
13481<p><b>Section:</b> 30.5.1 [thread.condition.condvar] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
13482 <b>Submitter:</b> Pete Becker <b>Opened:</b> 2009-01-07  <b>Last modified:</b> 2009-10-26</p>
13483<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#thread.condition.condvar">active issues</a> in [thread.condition.condvar].</p>
13484<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#thread.condition.condvar">issues</a> in [thread.condition.condvar].</p>
13485<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
13486<p><b>Discussion:</b></p>
13487<p>
1348830.5.1 [thread.condition.condvar]: <tt>condition_variable::wait_for</tt>
13489is required to compute the absolute time by adding the duration value to
13490<tt>chrono::monotonic_clock::now()</tt>, but <tt>monotonic_clock</tt> is not required to
13491exist.
13492</p>
13493
13494<p><i>[
13495Summit:
13496]</i></p>
13497
13498
13499<blockquote>
13500Move to open. Associate with LWG <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#859">859</a> and any other monotonic-clock
13501related issues.
13502</blockquote>
13503
13504<p><i>[
135052009-08-01 Howard adds:
13506]</i></p>
13507
13508
13509<blockquote>
13510I believe that <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#859">859</a> (currently Ready) addresses this issue, and
13511that this issue should be marked NAD, solved by <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#859">859</a> (assuming
13512it moves to WP).
13513</blockquote>
13514
13515<p><i>[
135162009-10 Santa Cruz:
13517]</i></p>
13518
13519
13520<blockquote>
13521Leave open, but expect to be fixed by N2969 revision that Detlef is writing.
13522</blockquote>
13523
13524
13525
13526<p><b>Proposed resolution:</b></p>
13527<p>
13528</p>
13529
13530
13531
13532
13533
13534<hr>
13535<h3><a name="960"></a>960. Various threading bugs #10</h3>
13536<p><b>Section:</b> 30.4.1 [thread.mutex.requirements] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
13537 <b>Submitter:</b> Pete Becker <b>Opened:</b> 2009-01-07  <b>Last modified:</b> 2009-10-26</p>
13538<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#thread.mutex.requirements">active issues</a> in [thread.mutex.requirements].</p>
13539<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#thread.mutex.requirements">issues</a> in [thread.mutex.requirements].</p>
13540<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
13541<p><b>Discussion:</b></p>
13542<p>
1354330.4.1 [thread.mutex.requirements]: paragraph 4 is entitled
13544"Error conditions", but according to 17.5.1.4 [structure.specifications], "Error
13545conditions:" specifies "the error conditions for error codes reported by
13546the function." It's not clear what this should mean when there is no
13547function in sight.
13548</p>
13549
13550<p><i>[
13551Summit:
13552]</i></p>
13553
13554
13555<blockquote>
13556Move to open.
13557</blockquote>
13558
13559<p><i>[
13560Beman provided proposed wording.
13561]</i></p>
13562
13563
13564<p><i>[
135652009-10 Santa Cruz:
13566]</i></p>
13567
13568
13569<blockquote>
13570Move to Ready. Fix the proposed wording with "functions of type Mutex"
13571-&gt; "functions of Mutex type"
13572</blockquote>
13573
13574
13575
13576<p><b>Proposed resolution:</b></p>
13577<p>
13578Change 30.4.1 [thread.mutex.requirements] Mutex requirements,
13579paragraph 4 as indicated:
13580</p>
13581
13582<blockquote>
13583<p>
13584-4- <del><i>Error conditions:</i></del>
13585<ins>The error conditions for error codes, if any, reported by member
13586functions of Mutex type shall be:</ins>
13587</p>
13588<ul>
13589<li>
13590<tt>not_enough_memory</tt> -- if there is not enough memory to construct
13591the mutex object.
13592</li>
13593<li>
13594<tt>resource_unavailable_try_again</tt> -- if any native handle type
13595manipulated is not available.
13596</li>
13597<li>
13598<tt>operation_not_permitted</tt> -- if the thread does not have the
13599necessary permission to change the state of the mutex object.
13600</li>
13601<li>
13602<tt>device_or_resource_busy</tt> -- if any native handle type
13603manipulated is already locked.
13604</li>
13605<li>
13606<tt>invalid_argument</tt> -- if any native handle type manipulated as
13607part of mutex construction is incorrect.
13608</li>
13609</ul>
13610</blockquote>
13611
13612
13613
13614
13615
13616<hr>
13617<h3><a name="962"></a>962. Various threading bugs #12</h3>
13618<p><b>Section:</b> 30.4.3.2.2 [thread.lock.unique.locking] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
13619 <b>Submitter:</b> Pete Becker <b>Opened:</b> 2009-01-07  <b>Last modified:</b> 2009-10-22</p>
13620<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#thread.lock.unique.locking">active issues</a> in [thread.lock.unique.locking].</p>
13621<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#thread.lock.unique.locking">issues</a> in [thread.lock.unique.locking].</p>
13622<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
13623<p><b>Discussion:</b></p>
13624<p>
1362530.4.3.2.2 [thread.lock.unique.locking]:  <tt>unique_lock::lock</tt> is
13626required to throw an object of type <tt>std::system_error</tt> "when the
13627postcondition cannot be achieved." The postcondition is <tt>owns == true</tt>,
13628and this is trivial to achieve. Presumably, the requirement is intended
13629to mean something more than that.
13630</p>
13631
13632<p><i>[
13633Summit:
13634]</i></p>
13635
13636<blockquote>
13637Move to open.
13638</blockquote>
13639
13640<p><i>[
13641Beman has volunteered to provide proposed wording.
13642]</i></p>
13643
13644
13645<p><i>[
136462009-07-21 Beman added wording to address 30.2.2 [thread.req.exception]
13647in response to the Frankfurt notes in <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#859">859</a>.
13648]</i></p>
13649
13650
13651<p><i>[
136522009-09-25 Beman: minor update to wording.
13653]</i></p>
13654
13655
13656<p><i>[
136572009-10 Santa Cruz:
13658]</i></p>
13659
13660
13661<blockquote>
13662Move to Ready.
13663</blockquote>
13664
13665
13666
13667<p><b>Proposed resolution:</b></p>
13668
13669<p><i>Change Exceptions 30.2.2 [thread.req.exception] as indicated:</i></p>
13670<blockquote>
13671<p>Some functions described in this Clause are specified to throw exceptions of 
13672type <code>system_error</code> (19.5.5). Such exceptions shall be thrown if <ins>
13673any of the <i>Error conditions</i> are detected or</ins> a call to an operating 
13674system or other underlying API results in an error that prevents the library 
13675function from <del>satisfying its postconditions or from returning a meaningful 
13676value</del> <ins>meeting its specifications</ins>. <ins>Failure to
13677allocate storage shall be reported as described in
1367817.6.4.11 [res.on.exception.handling].</ins></p>
13679</blockquote>
13680
13681<p><i>Change thread assignment 30.3.1.5 [thread.thread.member], join(), 
13682paragraph 8 as indicated:</i></p>
13683<blockquote>
13684<p><i>Throws:</i> <code>std::system_error</code> when <del>the postconditions cannot be achieved</del> <ins>an exception is required (30.2.2 [thread.req.exception])</ins>.</p>
13685
13686</blockquote>
13687
13688<p><i>Change thread assignment 30.3.1.5 [thread.thread.member], detach(), paragraph 
1368913 as indicated:</i></p>
13690<blockquote>
13691
13692<p><i>Throws:</i> <code>std::system_error</code> when <del>the effects or 
13693postconditions cannot be achieved</del> <ins>an exception is required (30.2.2 [thread.req.exception])</ins>.</p>
13694
13695</blockquote>
13696
13697<p><i>Change Mutex requirements 30.4.1 [thread.mutex.requirements], paragraph 
1369811, as indicated:</i></p>
13699<blockquote>
13700
13701<p><i>Throws:</i> <code>std::system_error</code> when <del>the effects or 
13702postcondition cannot be achieved</del> <ins>an exception is required (30.2.2 [thread.req.exception])</ins>.</p>
13703</blockquote>
13704<p><i>Change unique_lock locking 30.4.3.2.2 [thread.lock.unique.locking], 
13705paragraph 3, as indicated:</i></p>
13706<blockquote>
13707
13708<p><i>Throws:</i> <code>std::system_error</code> when <del>the  postcondition cannot be achieved</del> <ins>an exception is required (30.2.2 [thread.req.exception])</ins>.</p>
13709</blockquote>
13710<p><i>Change unique_lock locking 30.4.3.2.2 [thread.lock.unique.locking], 
13711paragraph 8, as indicated:</i></p>
13712<blockquote>
13713
13714<p><i>Throws:</i> <code>std::system_error</code> when <del>the  postcondition cannot be achieved</del> <ins>an exception is required (30.2.2 [thread.req.exception])</ins>.</p>
13715</blockquote>
13716<p><i>Change unique_lock locking 30.4.3.2.2 [thread.lock.unique.locking], 
13717paragraph 13, as indicated:</i></p>
13718<blockquote>
13719
13720<p><i>Throws:</i> <code>std::system_error</code> when <del>the  postcondition cannot be achieved</del> <ins>an exception is required (30.2.2 [thread.req.exception])</ins>.</p>
13721</blockquote>
13722<p><i>Change unique_lock locking 30.4.3.2.2 [thread.lock.unique.locking], 
13723paragraph 18, as indicated:</i></p>
13724<blockquote>
13725
13726<p><i>Throws:</i> <code>std::system_error</code> when <del>the  postcondition cannot be achieved</del> <ins>an exception is required (30.2.2 [thread.req.exception])</ins>.</p>
13727</blockquote>
13728<p><i>Change unique_lock locking 30.4.3.2.2 [thread.lock.unique.locking], 
13729paragraph 22, as indicated:</i></p>
13730<blockquote>
13731
13732<p><i>Throws:</i> <code>std::system_error</code> when <del>the  postcondition cannot be achieved</del> <ins>an exception is required (30.2.2 [thread.req.exception])</ins>.</p>
13733</blockquote>
13734<p><i>Change Function call_once 30.4.5.2 [thread.once.callonce], paragraph 4, as 
13735indicated</i></p>
13736<blockquote>
13737  <p><i>Throws:</i> <code>std::system_error</code> when <del>the effects cannot be achieved</del> <ins>an exception is required (30.2.2 [thread.req.exception])</ins>, 
13738  or any exception thrown by <code>func</code>.</p>
13739</blockquote>
13740<p><i>Change Class condition_variable 30.5.1 [thread.condition.condvar], 
13741paragraph 12, as indicated:</i></p>
13742<blockquote>
13743
13744<p><i>Throws:</i> <code>std::system_error</code> when <del>the effects or 
13745postcondition cannot be achieved</del> <ins>an exception is required (30.2.2 [thread.req.exception])</ins>.</p>
13746</blockquote>
13747<p><i>Change Class condition_variable 30.5.1 [thread.condition.condvar], 
13748paragraph 19, as indicated:</i></p>
13749<blockquote>
13750
13751<p><i>Throws:</i> <code>std::system_error</code> when <del>the effects or 
13752postcondition cannot be achieved</del> <ins>an exception is required (30.2.2 [thread.req.exception])</ins>.</p>
13753</blockquote>
13754<p><i>Change Class condition_variable_any 30.5.2 [thread.condition.condvarany], 
13755paragraph 10, as indicated:</i></p>
13756<blockquote>
13757
13758<p><i>Throws:</i> <code>std::system_error</code> when <del>the effects or 
13759postcondition cannot be achieved</del> <ins>an exception is required (30.2.2 [thread.req.exception])</ins>.</p>
13760</blockquote>
13761<p><i>Change Class condition_variable_any 30.5.2 [thread.condition.condvarany], 
13762paragraph 16, as indicated:</i></p>
13763<blockquote>
13764
13765<p><i>Throws:</i> <code>std::system_error</code> when <del>the returned value, effects, or 
13766postcondition cannot be achieved</del> <ins>an exception is required (30.2.2 [thread.req.exception])</ins>.</p>
13767</blockquote>
13768
13769<p><i>Assuming issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#859">859</a>, Monotonic Clock is Conditionally Supported?, has been 
13770applied to the working paper, change Change 30.5.1 [thread.condition.condvar] as 
13771indicated:</i></p>
13772<blockquote>
13773<pre>template &lt;class Rep, class Period&gt; 
13774bool wait_for(unique_lock&lt;mutex&gt;&amp; lock, 
13775              const chrono::duration&lt;Rep, Period&gt;&amp; rel_time);</pre>
13776<pre>...</pre>
13777
13778<p><i>Throws:</i> <code>std::system_error</code> when <del>the effects or 
13779postcondition cannot be achieved</del> <ins>an exception is required ([thread.req.exception])</ins>.</p>
13780</blockquote>
13781
13782<p><i>Assuming issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#859">859</a>, Monotonic Clock is Conditionally Supported?, has been 
13783applied to the working paper, change Change 30.5.1 [thread.condition.condvar] as 
13784indicated:</i></p>
13785<blockquote>
13786<pre>template &lt;class Rep, class Period, class Predicate&gt; 
13787  bool wait_for(unique_lock&lt;mutex&gt;&amp; lock, 
13788                const chrono::duration&lt;Rep, Period&gt;&amp; rel_time, 
13789                Predicate pred);</pre>
13790  <pre>...</pre>
13791
13792<p><i>Throws:</i> <code>std::system_error</code> when <del>the effects or 
13793postcondition cannot be achieved</del> <ins>an exception is required (30.2.2 [thread.req.exception])</ins>.</p>
13794</blockquote>
13795
13796<p><i>Assuming issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#859">859</a>, Monotonic Clock is Conditionally Supported?, has been 
13797applied to the working paper, change 30.5.2 [thread.condition.condvarany] as 
13798indicated:</i></p>
13799<blockquote>
13800<pre>template &lt;class Lock, class Rep, class Period&gt; 
13801  bool wait_for(Lock&amp; lock, const chrono::duration&lt;Rep, Period&gt;&amp; rel_time);</pre>
13802  <pre>...</pre>
13803
13804<p><i>Throws:</i> <code>std::system_error</code> when <del>the returned value, effects or 
13805postcondition cannot be achieved</del> <ins>an exception is required (30.2.2 [thread.req.exception])</ins>.</p>
13806</blockquote>
13807
13808<p><i>Assuming issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#859">859</a>, Monotonic Clock is Conditionally Supported?, has been 
13809applied to the working paper, change 30.5.2 [thread.condition.condvarany] as 
13810indicated:</i></p>
13811<blockquote>
13812<pre>template &lt;class Lock, class Rep, class Period, class Predicate&gt; 
13813  bool wait_for(Lock&amp; lock, const chrono::duration&lt;Rep, Period&gt;&amp; rel_time, Predicate pred);</pre>
13814  <pre>...</pre>
13815
13816<p><i>Throws:</i> <code>std::system_error</code> when <del>the returned value, effects or 
13817postcondition cannot be achieved</del> <ins>an exception is required (30.2.2 [thread.req.exception])</ins>.</p>
13818</blockquote>
13819
13820
13821
13822
13823
13824
13825<hr>
13826<h3><a name="963"></a>963. Various threading bugs #13</h3>
13827<p><b>Section:</b> 30.3.1.5 [thread.thread.member] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
13828 <b>Submitter:</b> Pete Becker <b>Opened:</b> 2009-01-07  <b>Last modified:</b> 2009-10-26</p>
13829<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#thread.thread.member">active issues</a> in [thread.thread.member].</p>
13830<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#thread.thread.member">issues</a> in [thread.thread.member].</p>
13831<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
13832<p><b>Discussion:</b></p>
13833<p>
1383430.3.1.5 [thread.thread.member]:  <tt>thread::detach</tt> is required to
13835throw an exception if the thread is "not a detachable thread".
13836"Detachable" is never defined.
13837</p>
13838
13839<p><i>[
13840Howard adds:
13841]</i></p>
13842
13843
13844<blockquote>
13845Due to a mistake on my part, 3 proposed resolutions appeared at approximately
13846the same time.  They are all three noted below in the discussion.
13847</blockquote>
13848
13849<p><i>[
13850Summit, proposed resolution:
13851]</i></p>
13852
13853
13854<blockquote>
13855<p>
13856In 30.3.1.5 [thread.thread.member] change:
13857</p>
13858
13859<blockquote><pre>void detach();
13860</pre>
13861<blockquote>
13862<p>...</p>
13863<p>-14- <i>Error conditions:</i></p>
13864<ul>
13865<li><tt>no_such_process</tt> --  <ins>if the thread is</ins> not <del>a</del> valid<del> thread</del>.</li>
13866<li><tt>invalid_argument</tt> -- <ins>if the thread is</ins> not <del>a detachable</del> <ins>joinable</ins><del> thread</del>.</li>
13867</ul>
13868</blockquote>
13869
13870</blockquote>
13871
13872</blockquote>
13873
13874<p><i>[
13875Post Summit, Jonathan Wakely adds:
13876]</i></p>
13877
13878
13879<blockquote>
13880<p>
13881A <tt>thread</tt> is detachable if it is joinable. As we've defined joinable,
13882we can just use that.
13883</p>
13884<p>
13885This corresponds to the pthreads specification, where pthread_detach
13886fails if the thread is not joinable:
13887</p>
13888<blockquote>
13889EINVAL: The  implementation  has  detected  that  the value specified by
13890thread does not refer to a joinable thread.
13891</blockquote>
13892<p>
13893Jonathan recommends this proposed wording:
13894</p>
13895<blockquote>
13896<p>
13897In 30.3.1.5 [thread.thread.member] change:
13898</p>
13899
13900<blockquote><pre>void detach();
13901</pre>
13902<blockquote>
13903<p>...</p>
13904<p>-14- <i>Error conditions:</i></p>
13905<ul>
13906<li>...</li>
13907<li><tt>invalid_argument</tt> -- not a <del>detachable</del> <ins>joinable</ins> thread.</li>
13908</ul>
13909</blockquote>
13910
13911</blockquote>
13912</blockquote>
13913</blockquote>
13914
13915<p><i>[
13916Post Summit, Anthony Williams adds:
13917]</i></p>
13918
13919
13920<blockquote>
13921<p>
13922This is covered by the precondition that <tt>joinable()</tt> be <tt>true</tt>.
13923</p>
13924<p>
13925Anthony recommends this proposed wording:
13926</p>
13927
13928<blockquote>
13929<p>
13930In 30.3.1.5 [thread.thread.member] change:
13931</p>
13932
13933<blockquote><pre>void detach();
13934</pre>
13935<blockquote>
13936<p>...</p>
13937<p>-14- <i>Error conditions:</i></p>
13938<ul>
13939<li>...</li>
13940<li><del><tt>invalid_argument</tt> -- not a detachable thread.</del></li>
13941</ul>
13942</blockquote>
13943
13944</blockquote>
13945
13946</blockquote>
13947
13948</blockquote>
13949
13950<p><i>[
139512009-10 Santa Cruz:
13952]</i></p>
13953
13954
13955<blockquote>
13956Mark as Ready with proposed resolution from Summit.
13957</blockquote>
13958
13959
13960
13961<p><b>Proposed resolution:</b></p>
13962
13963<p>
13964In 30.3.1.5 [thread.thread.member] change:
13965</p>
13966
13967<blockquote><pre>void detach();
13968</pre>
13969<blockquote>
13970<p>...</p>
13971<p>-14- <i>Error conditions:</i></p>
13972<ul>
13973<li><tt>no_such_process</tt> --  <ins>if the thread is</ins> not <del>a</del> valid<del> thread</del>.</li>
13974<li><tt>invalid_argument</tt> -- <ins>if the thread is</ins> not <del>a detachable</del> <ins>joinable</ins><del> thread</del>.</li>
13975</ul>
13976</blockquote>
13977
13978</blockquote>
13979
13980
13981
13982
13983
13984
13985<hr>
13986<h3><a name="964"></a>964. Various threading bugs #14</h3>
13987<p><b>Section:</b> 30.5.2 [thread.condition.condvarany] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
13988 <b>Submitter:</b> Pete Becker <b>Opened:</b> 2009-01-07  <b>Last modified:</b> 2009-10-26</p>
13989<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#thread.condition.condvarany">active issues</a> in [thread.condition.condvarany].</p>
13990<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#thread.condition.condvarany">issues</a> in [thread.condition.condvarany].</p>
13991<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
13992<p><b>Discussion:</b></p>
13993<p>
13994The requirements for the constructor for <tt>condition_variable</tt> has several
13995error conditions, but the requirements for the constructor for
13996<tt>condition_variable_any</tt> has none. Is this difference intentional?
13997</p>
13998
13999<p><i>[
14000Summit:
14001]</i></p>
14002
14003
14004<blockquote>
14005Move to open, pass to Howard. If this is intentional, a note may be
14006helpful. If the error conditions are to be copied from
14007<tt>condition_variable</tt>, this depends on LWG <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#965">965</a>.
14008</blockquote>
14009
14010<p><i>[
14011Post Summit Howard adds:
14012]</i></p>
14013
14014
14015<blockquote>
14016The original intention 
14017(<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2447.htm#ConditionVariablesWording">N2447</a>)
14018was to let the OS return whatever errors it was going to return, and for
14019those to be translated into exceptions, for both
14020<tt>condition_variable</tt> and <tt>condition_variable_any</tt>.  I have not
14021received any complaints about specific error conditions from vendors on
14022non-POSIX platforms, but such complaints would not surprise me if they surfaced.
14023</blockquote>
14024
14025<p><i>[
140262009-10 Santa Cruz:
14027]</i></p>
14028
14029
14030<blockquote>
14031Leave open. Benjamin to provide wording.
14032</blockquote>
14033
14034
14035
14036<p><b>Proposed resolution:</b></p>
14037
14038
14039
14040
14041
14042<hr>
14043<h3><a name="966"></a>966. Various threading bugs #16</h3>
14044<p><b>Section:</b> 30.5.1 [thread.condition.condvar] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
14045 <b>Submitter:</b> Pete Becker <b>Opened:</b> 2009-01-07  <b>Last modified:</b> 2009-10-26</p>
14046<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#thread.condition.condvar">active issues</a> in [thread.condition.condvar].</p>
14047<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#thread.condition.condvar">issues</a> in [thread.condition.condvar].</p>
14048<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
14049<p><b>Discussion:</b></p>
14050<p>
1405130.5.1 [thread.condition.condvar]:
14052<tt>condition_variable::wait</tt> and
14053<tt>condition_variable::wait_until</tt> both have a postcondition that
14054<tt>lock</tt> is locked by the calling thread, and a throws clause that
14055requires throwing an exception if this postcondition cannot be achieved.
14056How can the implementation detect that this <tt>lock</tt> can never be
14057obtained?
14058</p>
14059
14060<p><i>[
14061Summit:
14062]</i></p>
14063
14064
14065<blockquote>
14066Move to open. Requires wording. Agreed this is an issue, and the
14067specification should not require detecting deadlocks.
14068</blockquote>
14069
14070<p><i>[
140712009-08-01 Howard provides wording.
14072]</i></p>
14073
14074
14075<blockquote>
14076<p>
14077The proposed wording is inspired by the POSIX spec which says:
14078</p>
14079
14080<blockquote>
14081<dl>
14082<dt>[EINVAL]</dt>
14083<dd>The value specified by cond or mutex is invalid.</dd>
14084<dt>[EPERM]</dt>
14085<dd>The mutex was not owned by the current thread at the time of the call.</dd>
14086</dl>
14087</blockquote>
14088
14089<p>
14090I do not believe [EINVAL] is possible without memory corruption (which we don't
14091specify).  [EPERM] is possible if this thread doesn't own the mutex, which is
14092listed as a precondition.  "May" is used instead of "Shall" because not all
14093OS's are POSIX.
14094</p>
14095</blockquote>
14096
14097<p><i>[
140982009-10 Santa Cruz:
14099]</i></p>
14100
14101
14102<blockquote>
14103Leave open, Detlef to provide improved wording.
14104</blockquote>
14105
14106<p><i>[
141072009-10-23 Detlef Provided wording.
14108]</i></p>
14109
14110
14111<blockquote>
14112<p>
14113Detlef's wording put in Proposed resolution.  Original wording here:
14114</p>
14115<blockquote>
14116<p>
14117Change 30.5.1 [thread.condition.condvar] p12, p19 and
1411830.5.2 [thread.condition.condvarany] p10, p16:
14119</p>
14120
14121<blockquote>
14122<i>Throws:</i> <ins>May throw</ins> <tt>std::system_error</tt> 
14123<ins>
14124if a precondition is not met.
14125</ins>
14126<del>when the effects or postcondition
14127cannot be achieved.</del>
14128</blockquote>
14129</blockquote>
14130</blockquote>
14131
14132<p><i>[
141332009-10 Santa Cruz:
14134]</i></p>
14135
14136
14137<blockquote>
14138Leave open, Detlef to provide improved wording.
14139</blockquote>
14140
14141
14142
14143<p><b>Proposed resolution:</b></p>
14144<p>
14145Replace 30.5.1 [thread.condition.condvar] p12, p19 and
1414630.5.2 [thread.condition.condvarany] p10, p16:
14147</p>
14148
14149<blockquote>
14150<p><del>
14151<i>Throws:</i> <tt>std::system_error</tt> when the effects or
14152postcondition cannot be achieved.
14153</del></p>
14154<p><del>
14155Error conditions:
14156</del></p>
14157<ul>
14158<li><del>
14159equivalent error condition from <tt>lock.lock()</tt> or <tt>lock.unlock()</tt>.
14160</del></li>
14161</ul>
14162
14163<p><ins>
14164<i>Throws:</i> It's implementation-defined whether a <tt>std::system_error</tt>
14165with implementation-defined error condition is thrown if the
14166precondition is not met.
14167</ins></p>
14168</blockquote>
14169
14170
14171
14172
14173
14174
14175<hr>
14176<h3><a name="967"></a>967. Various threading bugs #17</h3>
14177<p><b>Section:</b> 30.3.1.2 [thread.thread.constr] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
14178 <b>Submitter:</b> Pete Becker <b>Opened:</b> 2009-01-07  <b>Last modified:</b> 2009-10-22</p>
14179<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#thread.thread.constr">active issues</a> in [thread.thread.constr].</p>
14180<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#thread.thread.constr">issues</a> in [thread.thread.constr].</p>
14181<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
14182<p><b>Discussion:</b></p>
14183<p>
14184the error handling for the constructor for <tt>condition_variable</tt>
14185distinguishes lack of memory from lack of other resources, but the error
14186handling for the thread constructor does not. Is this difference
14187intentional?
14188</p>
14189
14190<p><i>[
14191Beman has volunteered to provide proposed wording.
14192]</i></p>
14193
14194
14195<p><i>[
141962009-09-25 Beman provided proposed wording.
14197]</i></p>
14198
14199
14200<blockquote>
14201The proposed resolution assumes <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#962">962</a> has been accepted and
14202its proposed resolution applied to the working paper.
14203</blockquote>
14204
14205<p><i>[
142062009-10 Santa Cruz:
14207]</i></p>
14208
14209
14210<blockquote>
14211Move to Ready.
14212</blockquote>
14213
14214
14215
14216<p><b>Proposed resolution:</b></p>
14217
14218
14219<p><span style="font-style: italic;">Change Mutex requirements 30.4.1 [thread.mutex.requirements], 
14220paragraph 4, as indicated:</span></p>
14221<blockquote>
14222
14223<p><i>Error conditions:</i></p>
14224  <blockquote>
14225
14226<ul>
14227<li><del> <code>not_enough_memory</code> &#8212; if there is not enough memory to construct 
14228the mutex object.</del></li>
14229
14230<li><code>resource_unavailable_try_again</code> &#8212; if any native handle type 
14231manipulated is not available.</li>
14232
14233<li><code>operation_not_permitted</code> &#8212; if the thread does not have the 
14234necessary permission to change the state of the mutex object.</li>
14235
14236<li><code>device_or_resource_busy</code> &#8212; if any native handle type 
14237manipulated is already locked.</li>
14238
14239<li><code>invalid_argument</code> &#8212; if any native handle type manipulated as 
14240part of mutex construction is incorrect.</li>
14241</ul>
14242  </blockquote>
14243</blockquote>
14244
14245<p><span style="font-style: italic;">Change Class condition_variable 30.5.1 [thread.condition.condvar], 
14246default constructor, as indicated:</span></p>
14247<blockquote>
14248  <p><code>condition_variable();</code></p>
14249  <blockquote>
14250    <p><i>Effects:</i> Constructs an object of type <code>condition_variable</code>.</p>
14251    <p><ins><i>Throws:</i> <code>std::system_error</code> when an exception is required (30.2.2 [thread.req.exception])</ins>.</p>
14252    <p><i>Error conditions:</i></p>
14253    <blockquote>
14254    <ul>
14255      <li><del><code>not_enough_memory</code> &#8212; if a memory limitation prevents 
14256      initialization.</del></li>
14257      <li> <code>resource_unavailable_try_again</code> &#8212; if some non-memory 
14258      resource limitation prevents initialization.</li>
14259      <li> <code>device_or_resource_busy</code> &#8212; if attempting to initialize a 
14260      previously-initialized but as of yet undestroyed <code>condition_variable</code>.</li>
14261    </ul>
14262    </blockquote>
14263  </blockquote>
14264</blockquote>
14265
14266
14267
14268
14269
14270<hr>
14271<h3><a name="968"></a>968. Various threading bugs #18</h3>
14272<p><b>Section:</b> 30.4.1 [thread.mutex.requirements] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
14273 <b>Submitter:</b> Pete Becker <b>Opened:</b> 2009-01-07  <b>Last modified:</b> 2009-10-22</p>
14274<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#thread.mutex.requirements">active issues</a> in [thread.mutex.requirements].</p>
14275<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#thread.mutex.requirements">issues</a> in [thread.mutex.requirements].</p>
14276<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
14277<p><b>Discussion:</b></p>
14278<p>
1427930.4.1 [thread.mutex.requirements]: several functions are
14280required to throw exceptions "if the thread does not have the necessary
14281permission ...". "The necessary permission" is not defined.
14282</p>
14283
14284<p><i>[
14285Summit:
14286]</i></p>
14287
14288<blockquote>
14289Move to open.
14290</blockquote>
14291
14292
14293<p><i>[
14294Beman has volunteered to provide proposed wording.
14295]</i></p>
14296
14297
14298<p><i>[
142992009-10 Santa Cruz:
14300]</i></p>
14301
14302
14303<blockquote>
14304Moved to Ready with minor word-smithing in the example.
14305</blockquote>
14306
14307
14308
14309<p><b>Proposed resolution:</b></p>
14310
14311
14312<p><i>Change Exceptions 30.2.2 [thread.req.exception] as indicated:</i></p>
14313<blockquote>
14314<p>Some functions described in this Clause are 
14315specified to throw exceptions of type <code>system_error</code> (19.5.5). Such exceptions 
14316shall be thrown if any of the <i>Error conditions</i> are detected or a call to an operating system or other underlying API 
14317results in an error that prevents the library function from meeting its specifications.
14318<i>[Note:</i> See 17.6.4.11 [res.on.exception.handling] for exceptions thrown to report 
14319storage allocation failures. <i>&#8212;end 
14320note]</i></p>
14321
14322<p><ins><i>[Example:</i></ins></p>
14323
14324<blockquote>
14325
14326<p><ins>Consider a function in this clause that is specified to throw exceptions of type <code>
14327system_error</code> and specifies <i>Error conditions</i> that include <code>
14328operation_not_permitted</code> for a thread that does not have the privilege to 
14329perform the operation. Assume that, during the execution of this function, an <code>errno</code> 
14330of <code>EPERM</code> is reported by a POSIX API call used by the 
14331implementation. Since POSIX specifies an <code>errno</code> of <code>EPERM</code> 
14332when "the caller does not have the privilege to perform the operation", 
14333the implementation maps <code>EPERM</code>&nbsp; to an <code>error_condition</code> 
14334of <code>operation_not_permitted</code> (19.5 [syserr]) and an exception of type <code>
14335system_error</code> is thrown. </ins></p>
14336
14337</blockquote>
14338
14339<p><ins><i>&#8212;end example]</i></ins></p>
14340
14341<p><span style="font-style: italic;">Editorial note: For the sake of exposition, 
14342the existing text above is shown with the changes proposed in issues 962 and 967. The 
14343proposed additional example is independent of whether or not the 962 and 967 
14344proposed resolutions are accepted.</span></p>
14345
14346</blockquote>
14347
14348<p><span style="font-style: italic;">Change Mutex requirements 30.4.1 [thread.mutex.requirements], 
14349paragraph 4, as indicated:</span></p>
14350
14351<blockquote>
14352
14353<p>&#8212; <code>operation_not_permitted</code> &#8212; if the thread does not have the 
14354<del>necessary permission to change the state of the mutex object</del> <ins>privilege to perform the operation</ins>.</p>
14355
14356</blockquote>
14357
14358<p><span style="font-style: italic;">Change Mutex requirements 30.4.1 [thread.mutex.requirements], 
14359paragraph 12, as indicated:</span></p>
14360
14361<blockquote>
14362
14363<p>&#8212; <code>operation_not_permitted</code> &#8212; if the thread does not have the 
14364<del>necessary permission to change the state of the mutex</del> <ins>privilege to perform the operation</ins>.</p>
14365
14366</blockquote>
14367
14368
14369
14370
14371
14372
14373<hr>
14374<h3><a name="974"></a>974. <tt>duration&lt;double&gt;</tt> should not implicitly convert to <tt>duration&lt;int&gt;</tt></h3>
14375<p><b>Section:</b> 20.9.3.1 [time.duration.cons] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
14376 <b>Submitter:</b> Howard Hinnant <b>Opened:</b> 2009-01-21  <b>Last modified:</b> 2009-10-26</p>
14377<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
14378<p><b>Discussion:</b></p>
14379<p>
14380The following code should not compile because it involves implicit truncation
14381errors (against the design philosophy of the <tt>duration</tt> library).
14382</p>
14383
14384<blockquote><pre>duration&lt;double&gt; d(3.5);
14385duration&lt;int&gt; i = d;  <font color="#c80000">// implicit truncation, should not compile</font>
14386</pre></blockquote>
14387
14388<p>
14389This intent was codified in the example implementation which drove this proposal
14390but I failed to accurately translate the code into the specification in this
14391regard.
14392</p>
14393
14394<p><i>[
14395Batavia (2009-05):
14396]</i></p>
14397
14398<blockquote>
14399<p>
14400We agree with the proposed resolution.
14401</p>
14402<p>
14403Move to Tentatively Ready.
14404</p>
14405</blockquote>
14406
14407<p><i>[
144082009-07 Frankfurt
14409]</i></p>
14410
14411
14412<blockquote>
14413Moved from Tentatively Ready to Open only because the wording needs to be
14414improved for enable_if type constraining, possibly following Robert's
14415formula.
14416</blockquote>
14417
14418<p><i>[
144192009-08-01 Howard adds:
14420]</i></p>
14421
14422
14423<blockquote>
14424Addressed by <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1177">1177</a>.
14425</blockquote>
14426
14427<p><i>[
144282009-10 Santa Cruz:
14429]</i></p>
14430
14431
14432<blockquote>
14433Not completely addressed by <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1177">1177</a>.  Move to Ready.
14434</blockquote>
14435
14436
14437
14438<p><b>Proposed resolution:</b></p>
14439<p>
14440Change 20.9.3.1 [time.duration.cons], p4:
14441</p>
14442
14443<blockquote>
14444<pre>template &lt;class Rep2, class Period2&gt; 
14445  duration(const duration&lt;Rep2, Period2&gt;&amp; d);
14446</pre>
14447<blockquote>
14448-4- <i>Requires:</i> <tt>treat_as_floating_point&lt;rep&gt;::value</tt>
14449shall be <tt>true</tt> or <ins>both</ins> <tt>ratio_divide&lt;Period2,
14450period&gt;::type::den</tt> shall be 1
14451<ins>and <tt>treat_as_floating_point&lt;Rep2&gt;::value</tt>
14452shall be <tt>false</tt></ins>.
14453Diagnostic required.
14454[<i>Note:</i> This requirement prevents implicit truncation error when
14455converting between integral-based <tt>duration</tt> types. Such a
14456construction could easily lead to confusion about the value of the
14457<tt>duration</tt>. -- <i>end note</i>]
14458</blockquote>
14459</blockquote>
14460
14461
14462
14463
14464
14465<hr>
14466<h3><a name="978"></a>978. Hashing smart pointers</h3>
14467<p><b>Section:</b> 20.7.16 [unord.hash] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
14468 <b>Submitter:</b> Alisdair Meredith <b>Opened:</b> 2009-02-02  <b>Last modified:</b> 2009-10-27</p>
14469<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#unord.hash">active issues</a> in [unord.hash].</p>
14470<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#unord.hash">issues</a> in [unord.hash].</p>
14471<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
14472<p><b>Discussion:</b></p>
14473<p><b>Addresses UK 208</b></p>
14474<p>
14475I don't see an open issue on supporting <tt>std::hash</tt> for smart pointers
14476(<tt>unique_ptr</tt> and <tt>shared_ptr</tt> at least).
14477</p>
14478<p>
14479It seems reasonable to at least expect support for the smart
14480pointers, especially as they support comparison for use in ordered
14481associative containers.
14482</p>
14483
14484<p><i>[
14485Batavia (2009-05):
14486]</i></p>
14487
14488<blockquote>
14489<p>
14490Howard points out that the client can always supply a custom hash function.
14491</p>
14492<p>
14493Alisdair replies that the smart pointer classes are highly likely
14494to be frequently used as hash keys.
14495</p>
14496<p>
14497Bill would prefer to be conservative.
14498</p>
14499<p>
14500Alisdair mentions that this issue may also be viewed as a subissue or
14501duplicate of issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1025">1025</a>.
14502</p>
14503<p>
14504Move to Open, and recommend the issue be deferred until after the next
14505Committee Draft is issued.
14506</p>
14507</blockquote>
14508
14509<p><i>[
145102009-05-31 Peter adds:
14511]</i></p>
14512
14513
14514<blockquote>
14515<blockquote>
14516Howard points out that the client can always supply a custom hash function.
14517</blockquote>
14518<p>
14519Not entirely true. The client cannot supply the function that hashes the
14520address of the control block (the equivalent of the old <tt>operator&lt;</tt>, now
14521proudly carrying the awkward name of '<tt>owner_before</tt>'). Only the
14522implementation can do that, not necessarily via specializing <tt>hash&lt;&gt;</tt>, of
14523course.
14524</p>
14525<p>
14526This hash function makes sense in certain situations for <tt>shared_ptr</tt>
14527(when one needs to switch from <tt>set/map</tt> using ownership ordering to
14528<tt>unordered_set/map</tt>) and is the only hash function that makes sense for
14529<tt>weak_ptr</tt>.
14530</p>
14531</blockquote>
14532
14533<p><i>[
145342009-07-28 Alisdair provides wording.
14535]</i></p>
14536
14537
14538<p><i>[
145392009-10 Santa Cruz:
14540]</i></p>
14541
14542
14543<blockquote>
14544Move to Ready.
14545</blockquote>
14546
14547
14548
14549<p><b>Proposed resolution:</b></p>
14550<p>
14551Add the following declarations to the synopsis of <tt>&lt;memory&gt;</tt>
14552in 20.8 [memory]
14553</p>
14554
14555<blockquote><pre>// 20.8.10.X hash support
14556template &lt;class T&gt; struct hash;
14557template &lt;class T, class D&gt; struct hash&lt;unique_ptr&lt;T,D&gt;&gt;;
14558template &lt;class T&gt; struct hash&lt;shared_ptr&lt;T&gt;&gt;;
14559</pre></blockquote>
14560
14561<p>
14562Add a new subclause 20.8.10.X hash support
14563</p>
14564
14565<blockquote>
14566<p>
1456720.8.10.X hash support [util.smartptr.hash]
14568</p>
14569
14570<pre>template &lt;class T, class D&gt; struct hash&lt;unique_ptr&lt;T,D&gt;&gt;;
14571</pre>
14572
14573<blockquote>
14574A partial specialization of the class template <tt>hash</tt> (20.7.16 [unord.hash]) shall be provided for instances of the
14575<tt>unique_ptr</tt> template suitable for use as a key in unordered
14576associative containers (23.5 [unord]) if and only if there is a
14577<tt>hash</tt> specialization available for the type <tt>D::pointer</tt>.
14578For an object <tt>p</tt> of type <tt>unqiue_ptr&lt;T,D&gt;</tt> the
14579<tt>hash</tt> shall evaluate to the same value as <tt>hash&lt;typename
14580D::pointer&gt;{}(p.get())</tt>.
14581</blockquote>
14582
14583<pre>template &lt;class T&gt; struct hash&lt;shared_ptr&lt;T&gt;&gt;;
14584</pre>
14585
14586<blockquote>
14587A partial specialization of the class template <tt>hash</tt> (20.7.16 [unord.hash])
14588shall be provided for instances of the <tt>shared_ptr</tt> template
14589suitable for use as a key in unordered associative containers
14590(23.5 [unord]). For an object <tt>p</tt> of type <tt>shared_ptr&lt;T&gt;</tt>
14591the <tt>hash</tt> shall evaluate
14592to the same value as <tt>hash&lt;T*&gt;{}(p.get())</tt>.
14593</blockquote>
14594</blockquote>
14595
14596
14597
14598
14599
14600<hr>
14601<h3><a name="983"></a>983. <tt>unique_ptr</tt> reference deleters should not be moved from</h3>
14602<p><b>Section:</b> 20.8.14.2 [unique.ptr.single] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
14603 <b>Submitter:</b> Howard Hinnant <b>Opened:</b> 2009-02-10  <b>Last modified:</b> 2009-10-21</p>
14604<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#unique.ptr.single">active issues</a> in [unique.ptr.single].</p>
14605<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#unique.ptr.single">issues</a> in [unique.ptr.single].</p>
14606<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
14607<p><b>Discussion:</b></p>
14608<p>
14609Dave brought to my attention that when a <tt>unique_ptr</tt> has a non-const reference
14610type deleter, move constructing from it, even when the <tt>unique_ptr</tt> containing
14611the reference is an rvalue, could have surprising results:
14612</p>
14613
14614<blockquote><pre>D d(some-state);
14615unique_ptr&lt;A, D&amp;&gt; p(new A, d);
14616unique_ptr&lt;A, D&gt; p2 = std::move(p);
14617<font color="#c80000">// has d's state changed here?</font>
14618</pre></blockquote>
14619
14620<p>
14621I agree with him.  It is the <tt>unique_ptr</tt> that is the rvalue, not the
14622deleter.  When the deleter is a reference type, the <tt>unique_ptr</tt> should
14623respect the "lvalueness" of the deleter.
14624</p>
14625
14626<p>
14627Thanks Dave.
14628</p>
14629
14630<p><i>[
14631Batavia (2009-05):
14632]</i></p>
14633
14634<blockquote>
14635Seems correct, but complicated enough that we recommend moving to Review.
14636</blockquote>
14637
14638<p><i>[
146392009-10 Santa Cruz:
14640]</i></p>
14641
14642
14643<blockquote>
14644Move to Ready.
14645</blockquote>
14646
14647
14648
14649<p><b>Proposed resolution:</b></p>
14650<p>
14651Change 20.8.14.2.1 [unique.ptr.single.ctor], p20-21
14652</p>
14653
14654<blockquote>
14655<pre>template &lt;class U, class E&gt; unique_ptr(unique_ptr&lt;U, E&gt;&amp;&amp; u);
14656</pre>
14657
14658<blockquote>
14659
14660<p>
14661-20- <i>Requires:</i> If <tt><del>D</del> <ins>E</ins></tt> is not a reference type,
14662construction of the deleter <tt>D</tt> from an rvalue of type <tt>E</tt>
14663shall be well formed and shall not throw an exception.
14664<ins>
14665Otherwise <tt>E</tt> is a reference type and construction of the deleter
14666<tt>D</tt> from an lvalue of type <tt>E</tt> shall be well formed and
14667shall not throw an exception.
14668</ins>
14669If <tt>D</tt> is
14670a reference type, then <tt>E</tt> shall be the same type as <tt>D</tt>
14671(diagnostic required). <tt>unique_ptr&lt;U, E&gt;::pointer</tt> shall be
14672implicitly convertible to <tt>pointer</tt>. [<tt>Note:</tt> These
14673requirements imply that <tt>T</tt> and <tt>U</tt> are complete types.
14674<i>-- end note</i>]
14675</p>
14676
14677<p>
14678-21- <i>Effects:</i> Constructs a <tt>unique_ptr</tt> which owns the
14679pointer which <tt>u</tt> owns (if any). If the deleter
14680<ins><tt>E</tt></ins> is not a reference type, <del>it</del> <ins>this
14681deleter</ins> is move constructed from <tt>u</tt>'s deleter, otherwise
14682<del>the reference</del> <ins>this deleter</ins> is copy constructed
14683from <tt>u</tt>.'s deleter. After the construction, <tt>u</tt> no longer
14684owns a pointer. [<i>Note:</i> The deleter constructor can be implemented
14685with <tt>std::forward&lt;<del>D</del><ins>E</ins>&gt;</tt>. <i>-- end
14686note</i>]
14687</p>
14688
14689</blockquote>
14690</blockquote>
14691
14692<p>
14693Change 20.8.14.2.3 [unique.ptr.single.asgn], p1-3
14694</p>
14695
14696<blockquote>
14697<pre>unique_ptr&amp; operator=(unique_ptr&amp;&amp; u);
14698</pre>
14699<blockquote>
14700
14701<p>
14702-1- <i>Requires:</i> <ins>If the deleter <tt>D</tt> is not a reference type,</ins>
14703<del>A</del><ins>a</ins>ssignment of the deleter <tt>D</tt> from an rvalue <tt>D</tt> shall not throw an exception.
14704<ins>
14705Otherwise the deleter <tt>D</tt> is a reference type,
14706and assignment of the deleter <tt>D</tt> from an lvalue <tt>D</tt> shall not throw an exception.</ins>
14707</p>
14708
14709<p>
14710-2- <i>Effects:</i> reset(u.release()) followed by
14711a<ins>n</ins> <del>move</del> assignment from <del><tt>u</tt>'s deleter to this deleter</del>
14712<ins><tt>std::forward&lt;D&gt;(u.get_deleter())</tt></ins>.
14713</p>
14714
14715<p>
14716-3- <i>Postconditions:</i> This <tt>unique_ptr</tt> now owns the pointer
14717which <tt>u</tt> owned, and <tt>u</tt> no longer owns it. <del>[<i>Note:</i> If
14718<tt>D</tt> is a reference type, then the referenced lvalue deleters are
14719move assigned. <i>-- end note</i>]</del>
14720</p>
14721</blockquote>
14722</blockquote>
14723
14724<p>
14725Change 20.8.14.2.3 [unique.ptr.single.asgn], p6-7
14726</p>
14727
14728<blockquote>
14729<pre>template &lt;class U, class E&gt; unique_ptr&amp; operator=(unique_ptr&lt;U, E&gt;&amp;&amp; u);
14730</pre>
14731<blockquote>
14732
14733<p>
14734<i>Requires:</i> <ins>If the deleter <tt>E</tt> is not a reference type,</ins>
14735<del>A</del><ins>a</ins>ssignment of the deleter <tt>D</tt> from an rvalue
14736<tt><del>D</del><ins>E</ins></tt> shall not throw an exception.
14737<ins>
14738Otherwise the deleter <tt>E</tt> is a reference type,
14739and assignment of the deleter <tt>D</tt> from an lvalue <tt>E</tt> shall not throw an exception.</ins>
14740<tt>unique_ptr&lt;U, E&gt;::pointer</tt> shall be implicitly convertible to <tt>pointer</tt>.
14741[<i>Note:</i> These requirements imply that <tt>T</tt> and <tt>U&gt;</tt>
14742are complete types. <i>-- end note</i>]
14743</p>
14744
14745<p>
14746<i>Effects:</i> <tt>reset(u.release())</tt> followed by
14747a<ins>n</ins> <del>move</del> assignment from <del><tt>u</tt>'s deleter to this deleter</del>
14748<ins><tt>std::forward&lt;E&gt;(u.get_deleter())</tt></ins>.
14749<del>If either
14750<tt>D</tt> or <tt>E</tt> is a reference type, then the referenced lvalue
14751deleter participates in the move assignment.</del>
14752</p>
14753
14754</blockquote>
14755</blockquote>
14756
14757
14758
14759
14760
14761
14762<hr>
14763<h3><a name="985"></a>985. Allowing throwing move</h3>
14764<p><b>Section:</b> 23.2.1 [container.requirements.general] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
14765 <b>Submitter:</b> Rani Sharoni <b>Opened:</b> 2009-02-12  <b>Last modified:</b> 2009-10-20</p>
14766<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#container.requirements.general">active issues</a> in [container.requirements.general].</p>
14767<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#container.requirements.general">issues</a> in [container.requirements.general].</p>
14768<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
14769<p><b>Discussion:</b></p>
14770<p>
14771<b>Introduction</b>
14772</p>
14773
14774<p>This proposal is meant to resolve potential regression of the
14775<a href="" ref="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2800.pdf">N2800</a>
14776draft, see
14777next section, and to relax the requirements for containers of types with
14778throwing move constructors.</p>
14779
14780<p>The basic problem is that some containers operations, like <tt>push_back</tt>,
14781have a strong exception safety
14782guarantee (i.e. no side effects upon exception) that are not achievable when
14783throwing move constructors are used since there is no way to guarantee revert
14784after partial move. For such operations the implementation can at most provide
14785the basic guarantee (i.e. valid but unpredictable) as it does with multi
14786copying operations (e.g. range insert).</p>
14787
14788<p>For example, <tt>vector&lt;T&gt;::push_back()</tt> (where <tt>T</tt> has a move
14789constructor) might resize the <tt>vector</tt> and move the objects to the new underlying
14790buffer. If move constructor throws it might
14791not be possible to recover the throwing object or to move the old objects back to
14792the original buffer.</p>
14793
14794<p>The current draft is explicit by disallowing throwing move
14795for some operations (e.g. <tt>vector&lt;&gt;::reserve</tt>) and not clear about other
14796operations mentioned in 23.2.1 [container.requirements.general]/10
14797(e.g. single element <tt>insert</tt>): it guarantees strong exception
14798safety without explicitly disallowing a throwing move constructor.
14799</p>
14800
14801<p>
14802<b>Regression</b>
14803</p>
14804
14805<p>This section only refers to cases in which the contained object
14806is by itself a standard container.</p>
14807
14808<p>Move constructors of standard containers are allowed to throw and therefore
14809existing operations are broken, compared with C++03, due to move optimization.
14810(In fact existing implementations like Dinkumware are actually throwing).</p>
14811
14812<p>For example, <tt>vector&lt; list&lt;int&gt; &gt;::reserve</tt> yields
14813undefined behavior since <tt>list&lt;int&gt;</tt>'s move constructor is allowed to throw.
14814On the other hand, the same operation has strong exception safety guarantee in
14815C++03.</p>
14816
14817<p>There are few options to solve this regression:</p>
14818
14819<ol>
14820<li>
14821Disallow throwing move and throwing default constructor
14822</li>
14823
14824<li>
14825Disallow throwing move but disallowing usage after move
14826</li>
14827
14828<li>
14829Special casing
14830</li>
14831
14832<li>
14833Disallow throwing move and making it optional
14834</li>
14835
14836</ol>
14837
14838<p>Option 1 is suggested by proposal
14839<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2815.html">N2815</a>
14840but it might not be applicable for existing implementations for which
14841containers default constructors are throwing.</p>
14842
14843<p>Option 2 limits the usage significantly and it's error prone
14844by allowing zombie objects that are nothing but destructible (e.g. no <tt>clear()</tt>
14845is allowed after move). It also potentially complicates the implementation by
14846introducing special state.</p>
14847
14848<p>Option 3 is possible, for example, using default
14849construction and <tt>swap</tt> instead of move for standard containers case. The
14850implementation is also free to provide special hidden operation for non
14851throwing move without forcing the user the cope with the limitation of option-2
14852when using the public move.</p>
14853
14854<p>Option 4 impact the efficiency in all use cases due to rare throwing move.</p>
14855
14856<p>The proposed wording will imply option 1 or 3 though option 2 is also
14857achievable using more wording. I personally oppose to option 2 that has impact
14858on usability.</p>
14859
14860<p>
14861<b>Relaxation for user types</b>
14862</p>
14863
14864<p>Disallowing throwing move constructors in general seems very restrictive
14865since, for example, common implementation of move will be default construction
14866+ <tt>swap</tt> so move will throw if the
14867default constructor will throw. This is currently the case with the Dinkumware
14868implementation of node based containers (e.g. <tt>std::list</tt>)
14869though this section doesn't refer to standard types.</p>
14870
14871<p>For throwing move constructors it seem that the implementation should have
14872no problems to provide the basic guarantee instead of the strong one. It's
14873better to allow throwing move constructors with basic guarantee than to
14874disallow it silently (compile and run), via undefined behavior.</p>
14875
14876<p>There might still be cases in which the relaxation will break existing generic
14877code that assumes the strong guarantee but it's broken either way given a
14878throwing move constructor since this is not a preserving optimization. </p>
14879
14880<p><i>[
14881Batavia (2009-05):
14882]</i></p>
14883
14884<blockquote>
14885<p>
14886Bjarne comments (referring to his draft paper):
14887"I believe that my suggestion simply solves that.
14888Thus, we don't need a throwing move."
14889</p>
14890<p>
14891Move to Open and recommend it be deferred until after the next
14892Committee Draft is issued.
14893</p>
14894</blockquote>
14895
14896<p><i>[
148972009-10 Santa Cruz:
14898]</i></p>
14899
14900
14901<blockquote>
14902Should wait to get direction from Dave/Rani
14903(<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2983.html">N2983</a>).
14904</blockquote>
14905
14906
14907
14908<p><b>Proposed resolution:</b></p>
14909
14910<p>
1491123.2.1 [container.requirements.general]  paragraph 10 add footnote:
14912</p>
14913
14914<blockquote>
14915<p>
14916-10- Unless otherwise specified (see 23.1.4.1, 23.1.5.1, 23.2.2.3, and
1491723.2.6.4) all container types defined in this Clause meet the following
14918additional requirements:
14919</p>
14920<ul>
14921<li>...</li>
14922</ul>
14923
14924<p>
14925<ins>[<i>Note</i>: for compatibility with C++
149262003, when "no effect" is required, standard containers should not use the
14927value_type's throwing move constructor when the contained object is by itself a
14928standard container. -- <i>end note</i>]</ins>
14929</p>
14930
14931</blockquote>
14932
14933<p>23.2.5.1 [unord.req.except] change paragraph 2 to say: </p>
14934
14935<blockquote>
14936<p>
14937-2- For unordered associative containers, if an exception is
14938thrown by any operation other than the container's hash function from within an
14939<tt>insert()</tt> function inserting a single element, the <tt>insert()</tt>
14940function has no effect<ins> unless the exception is thrown by the contained
14941object move constructor</ins>.
14942</p>
14943
14944<p>
14945-4- For unordered associative containers, if an exception is
14946thrown from within a <tt>rehash()</tt> function other than by the container's hash
14947function or comparison function, the <tt>rehash()</tt> function has no effect
14948<ins>unless the exception is thrown by the contained
14949object move constructor</ins>.</p>
14950
14951</blockquote>
14952
14953<p>
1495423.3.2.3 [deque.modifiers] change paragraph 2 to say:
14955</p>
14956
14957<blockquote>
14958-2- <i>Remarks:</i> If an exception is thrown other than by
14959the copy constructor<ins>, move constructor</ins>
14960or assignment operator of <tt>T</tt>
14961there are no effects.
14962<ins>If an exception is thrown by <tt>push_back()</tt> or <tt>emplace_back()</tt>
14963function, that function has no effects unless the exception is thrown by
14964the move constructor of <tt>T</tt>.</ins>
14965</blockquote>
14966
14967<p>
1496823.3.2.3 [deque.modifiers] change paragraph 6 to say:
14969</p>
14970
14971<blockquote>
14972-6- <i>Throws:</i> Nothing unless an exception is thrown by the copy
14973constructor<ins>, move constructor</ins> or assignment operator of <tt>T</tt>.
14974</blockquote>
14975
14976<p>
1497723.3.6.2 [vector.capacity] remove paragraph 2
14978</p>
14979
14980<blockquote>
14981<del>-2- <i>Requires:</i> If <tt>value_type</tt> has a move constructor,
14982that constructor shall not throw any exceptions.</del>
14983</blockquote>
14984
14985<p>
1498623.3.6.2 [vector.capacity] paragraph 3 change to say:
14987</p>
14988
14989<blockquote>
14990-3- <i>Effects:</i> A directive that informs a <tt>vector</tt>
14991of a planned change in size, so
14992that it can manage the storage allocation accordingly. After <tt>reserve()</tt>,
14993<tt>capacity()</tt> is greater or equal to the argument of <tt>reserve</tt>
14994if reallocation happens; and equal
14995to the previous value of <tt>capacity()</tt>
14996otherwise. Reallocation happens at this point if and only if the current
14997capacity is less than the argument of <tt>reserve()</tt>.
14998If an exception is thrown, there are no effects<ins>
14999unless the exception is thrown by the contained object move constructor</ins>.
15000</blockquote>
15001
15002<p>
1500323.3.6.2 [vector.capacity] paragraph 12 change to say:
15004</p>
15005
15006<blockquote>
15007-12- <i>Requires:</i> <del>If <tt>value_type</tt> has a move constructor,
15008that constructor shall not throw any exceptions.</del>
15009<ins>If an exception is thrown, there are no effects unless the exception is thrown by
15010the contained object move constructor.</ins>
15011</blockquote>
15012
15013<p>
1501423.3.6.4 [vector.modifiers] change paragraph 1 to say:
15015</p>
15016
15017<blockquote>
15018-1- <del><i>Requires:</i> If <tt>value_type</tt> has a move constructor,
15019that constructor shall not throw any exceptions.</del>
15020<ins><i>Remarks:</i> If an exception is thrown by <tt>push_back()</tt>
15021or <tt>emplace_back()</tt> function, that function has no effect unless the
15022exception is thrown by the move constructor of <tt>T</tt>.</ins>
15023</blockquote>
15024
15025<p>
1502623.3.6.4 [vector.modifiers] change paragraph 2 to say:
15027</p>
15028
15029<blockquote>
15030-2- <i>Remarks:</i> Causes reallocation if the new size is greater than
15031the old capacity. If no reallocation happens, all the iterators and
15032references before the insertion point remain valid. If an exception is
15033thrown other than by the copy constructor<ins>, move constructor</ins>
15034or assignment operator of <tt>T</tt> or by any <tt>InputIterator</tt>
15035operation there are no effects.
15036</blockquote>
15037
15038<p>
1503923.3.6.4 [vector.modifiers] change paragraph 6 to say:
15040</p>
15041
15042<blockquote>
15043-6- <i>Throws:</i> Nothing unless an exception is thrown by the copy
15044constructor<ins>, move constructor</ins> or assignment operator of <tt>T</tt>.
15045</blockquote>
15046
15047
15048
15049
15050
15051
15052<hr>
15053<h3><a name="987"></a>987. <tt>reference_wrapper</tt> and function types</h3>
15054<p><b>Section:</b> 20.7.5 [refwrap] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Tentatively Ready</a>
15055 <b>Submitter:</b> Howard Hinnant <b>Opened:</b> 2009-02-18  <b>Last modified:</b> 2009-10-26</p>
15056<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#refwrap">issues</a> in [refwrap].</p>
15057<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Tentatively%20Ready">Tentatively Ready</a> status.</p>
15058<p><b>Discussion:</b></p>
15059<p>
15060The synopsis in 20.7.5 [refwrap] says:
15061</p>
15062
15063<blockquote><pre>template &lt;<b>ObjectType</b> T&gt; class reference_wrapper
15064...
15065</pre></blockquote>
15066
15067<p>
15068And then paragraph 3 says:
15069</p>
15070
15071<blockquote>
15072<p>
15073The template instantiation <tt>reference_wrapper&lt;T&gt;</tt> shall be
15074derived from <tt>std::unary_function&lt;T1, R&gt;</tt> only if the type
15075<tt>T</tt> is any of the following:
15076</p>
15077
15078<ul>
15079<li>
15080a <b>function type</b> or a pointer to function type taking one argument of
15081type <tt>T1</tt> and returning <tt>R</tt>
15082</li>
15083</ul>
15084</blockquote>
15085
15086<p>
15087But function types are not <tt>ObjectType</tt>s.
15088</p>
15089
15090<p>
15091Paragraph 4 contains the same contradiction.
15092</p>
15093
15094<p><i>[
15095Post Summit:
15096]</i></p>
15097
15098
15099<blockquote>
15100<p>
15101Jens: restricted reference to ObjectType
15102</p>
15103<p>
15104Recommend Review.
15105</p>
15106</blockquote>
15107
15108<p><i>[
15109Post Summit, Peter adds:
15110]</i></p>
15111
15112
15113<blockquote>
15114<p>
15115In <a href="https://svn.boost.org/trac/boost/ticket/1846">https://svn.boost.org/trac/boost/ticket/1846</a>
15116however Eric Niebler makes the very reasonable point that <tt>reference_wrapper&lt;F&gt;</tt>,
15117where <tt>F</tt> is a function type, represents a reference to a function,
15118a legitimate entity. So <tt>boost::ref</tt> was changed to allow it.
15119</p>
15120<p>
15121<a href="https://svn.boost.org/trac/boost/browser/trunk/libs/bind/test/ref_fn_test.cpp">https://svn.boost.org/trac/boost/browser/trunk/libs/bind/test/ref_fn_test.cpp</a>
15122</p>
15123<p>
15124Therefore, I believe an alternative proposed resolution for issue 987 could simply
15125allow <tt>reference_wrapper</tt> to be used with function types.
15126</p>
15127</blockquote>
15128
15129<p><i>[
15130Post Summit, Howard adds:
15131]</i></p>
15132
15133
15134<blockquote>
15135<p>
15136I agree with Peter (and Eric).  I got this one wrong on my first try.  Here
15137is code that demonstrates how easy (and useful) it is to instantiate
15138<tt>reference_wrapper</tt> with a function type:
15139</p>
15140
15141<blockquote><pre>#include &lt;functional&gt;
15142
15143template &lt;class F&gt;
15144void test(F f);
15145
15146void f() {}
15147
15148int main()
15149{
15150    test(std::ref(f));
15151}
15152</pre></blockquote>
15153
15154<p>
15155Output (link time error shows type of <tt>reference_wrapper</tt> instantiated
15156with function type):
15157</p>
15158
15159<blockquote><pre>Undefined symbols:
15160  "void test&lt;std::reference_wrapper&lt;void ()()&gt; &gt;(std::reference_wrapper&lt;void ()()&gt;)",...
15161</pre></blockquote>
15162
15163<p>
15164I've taken the liberty of changing the proposed wording to allow function types
15165and set to Open.  I'll also freely admit that I'm not positive <tt>ReferentType</tt>
15166is the correct concept.
15167</p>
15168
15169</blockquote>
15170
15171
15172
15173<p><i>[
15174Batavia (2009-05):
15175]</i></p>
15176
15177<blockquote>
15178<p>
15179Howard observed that <tt>FunctionType</tt>,
15180a concept not (yet?) in the Working Paper,
15181is likely the correct constraint to be applied.
15182However, the proposed resolution provides an adequate approximation.
15183</p>
15184<p>
15185Move to Review.
15186</p>
15187</blockquote>
15188
15189<p><i>[
151902009-05-23 Alisdair adds:
15191]</i></p>
15192
15193
15194<blockquote>
15195<p>
15196By constraining to <tt>PointeeType</tt> we rule out the ability for <tt>T</tt> to be a
15197reference, and call in reference-collapsing.  I'm not sure if this is
15198correct and intended, but would like to be sure the case was considered.
15199</p>
15200<p>
15201Is dis-allowing reference types and the
15202implied reference collapsing the intended result?
15203</p>
15204</blockquote>
15205
15206<p><i>[
152072009-07 Frankfurt
15208]</i></p>
15209
15210
15211<blockquote>
15212Moved from Review to Open only because the wording needs to be
15213tweaked for concepts removal.
15214</blockquote>
15215
15216<p><i>[
152172009-10-14 Daniel provided de-conceptified wording.
15218]</i></p>
15219
15220
15221<p><i>[
152222009-10 post-Santa Cruz:
15223]</i></p>
15224
15225
15226<blockquote>
15227Move to Tentatively Ready.
15228</blockquote>
15229
15230
15231
15232<p><b>Proposed resolution:</b></p>
15233<p>
15234Change 20.7.5 [refwrap]/1 as indicated:
15235</p>
15236
15237<blockquote>
15238<tt>reference_wrapper&lt;T&gt;</tt> is a <tt>CopyConstructible</tt> and
15239<tt><ins>Copy</ins>Assignable</tt> wrapper around a
15240reference to an object <ins>or function</ins> of type <tt>T</tt>.
15241</blockquote>
15242
15243
15244
15245
15246
15247<p><b>Rationale:</b></p>
15248<p>
15249a) The occurrence of <tt>T&amp;</tt> in the function signature auto-implies
15250<tt>std::ReferentType</tt>,
15251this is due to  [temp.req.impl]/4 bullet 4
15252</p>
15253<p>
15254b) The occurrence of the constrained template <tt>reference_wrapper&lt;T&gt;</tt> in
15255the remaining
15256signatures lets kick in  [temp.req.impl]/4 bullet 1 and adds *all* requirements of
15257this template. But we need to add at least *one* requirement (and it
15258was an arbitrary,
15259but natural decision to require <tt>std::PointeeType</tt> here) to *activate*
15260this. If we hadn't done
15261this, we were in unconstrained mode!
15262</p>
15263
15264
15265
15266
15267
15268<hr>
15269<h3><a name="996"></a>996. Move operation not well specified</h3>
15270<p><b>Section:</b> 17 [library] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
15271 <b>Submitter:</b> David Abrahams <b>Opened:</b> 2009-03-06  <b>Last modified:</b> 2009-05-23</p>
15272<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#library">active issues</a> in [library].</p>
15273<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#library">issues</a> in [library].</p>
15274<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
15275<p><b>Discussion:</b></p>
15276<p>
15277There are lots of places in the standard where we talk about "the move
15278constructor" but where we mean "the move operation," i.e.  <tt>T( move( x ) )</tt>.
15279</p>
15280<p>
15281We also don't account for whether that operation modifies <tt>x</tt> or not, and
15282we need to.
15283</p>
15284
15285<p><i>[
15286Batavia (2009-05):
15287]</i></p>
15288
15289<blockquote>
15290Move to Open, pending proposed wording from Dave for further
15291review.
15292</blockquote>
15293
15294
15295<p><b>Proposed resolution:</b></p>
15296<p>
15297</p>
15298
15299
15300
15301
15302
15303<hr>
15304<h3><a name="999"></a>999. Taking the address of a function</h3>
15305<p><b>Section:</b> 20.8.13 [specialized.algorithms] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Tentatively Ready</a>
15306 <b>Submitter:</b> Peter Dimov <b>Opened:</b> 2009-03-09  <b>Last modified:</b> 2009-10-26</p>
15307<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#specialized.algorithms">issues</a> in [specialized.algorithms].</p>
15308<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Tentatively%20Ready">Tentatively Ready</a> status.</p>
15309<p><b>Discussion:</b></p>
15310<p>
15311The same fix (reference <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#987">987</a>) may be applied to <tt>addressof</tt>, which is also constrained to
15312<tt>ObjectType</tt>. (That was why <tt>boost::ref</tt> didn't work with functions - it
15313tried to apply <tt>boost::addressof</tt> and the <tt>reinterpret_cast&lt;char&amp;&gt;</tt>
15314implementation of <tt>addressof</tt> failed.)
15315</p>
15316
15317
15318
15319<p><i>[
15320Batavia (2009-05):
15321]</i></p>
15322
15323<blockquote>
15324<p>
15325We agree.
15326</p>
15327<p>
15328Move to Tentatively Ready.
15329</p>
15330</blockquote>
15331
15332<p><i>[
153332009-07 Frankfurt
15334]</i></p>
15335
15336
15337<blockquote>
15338Moved from Tentatively Ready to Open only because the wording needs to be
15339tweaked for concepts removal.
15340</blockquote>
15341
15342<p><i>[
153432009-10-10 Daniel updates wording to concept-free.
15344]</i></p>
15345
15346
15347<p><i>[
153482009-10 post-Santa Cruz:
15349]</i></p>
15350
15351
15352<blockquote>
15353Move to Tentatively Ready.
15354</blockquote>
15355
15356
15357
15358<p><b>Proposed resolution:</b></p>
15359<p><i>[
15360The resolution assumes that <tt>addressof</tt> is reintroduced as described in
15361<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2946.pdf">n2946</a>
15362]</i></p>
15363
15364
15365<p>
15366In 20.8.13 [specialized.algorithms] change as described:
15367</p>
15368
15369<blockquote><pre>template &lt;class T&gt; T* addressof(T&amp; r);
15370</pre>
15371<blockquote>
15372<i>Returns:</i> The actual address of the object <ins>or function</ins>
15373referenced by <tt>r</tt>, even in the
15374presence of an overloaded <tt>operator&amp;</tt>.
15375</blockquote>
15376</blockquote>
15377
15378
15379
15380
15381<p><b>Rationale:</b></p>
15382<p>
15383a) The occurrence of <tt>T&amp;</tt> in the function signature auto-implies
15384<tt>std::ReferentType</tt>,
15385this is due to  [temp.req.impl]/4 bullet 4
15386</p>
15387
15388
15389
15390
15391
15392<hr>
15393<h3><a name="1008"></a>1008. <tt>nested_exception</tt> wording unclear</h3>
15394<p><b>Section:</b> 18.8.6 [except.nested] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
15395 <b>Submitter:</b> Alisdair Meredith <b>Opened:</b> 2009-03-11  <b>Last modified:</b> 2009-10-22</p>
15396<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#except.nested">active issues</a> in [except.nested].</p>
15397<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#except.nested">issues</a> in [except.nested].</p>
15398<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
15399<p><b>Discussion:</b></p>
15400
15401<p><b>Addresses JP 31</b></p>
15402
15403<p>
15404It is difficult to understand in which case <tt>nested_exception</tt> is applied.
15405</p>
15406
15407<p><i>[
15408Summit:
15409]</i></p>
15410
15411 
15412<blockquote>
15413Alisdair will add an example in an update to
15414<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2619.pdf">N2619</a>.
15415</blockquote>
15416
15417<p><i>[
154182009-10 Santa Cruz:
15419]</i></p>
15420
15421
15422<blockquote>
15423It doesn't appear that N2619 really addresses this. Alisdair to propose wording.
15424</blockquote>
15425
15426
15427
15428<p><b>Proposed resolution:</b></p>
15429
15430
15431
15432
15433
15434<hr>
15435<h3><a name="1011"></a>1011. <tt>next/prev</tt> wrong iterator type</h3>
15436<p><b>Section:</b> 24.4.4 [iterator.operations] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
15437 <b>Submitter:</b> Alisdair Meredith <b>Opened:</b> 2009-03-11  <b>Last modified:</b> 2009-10-22</p>
15438<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#iterator.operations">active issues</a> in [iterator.operations].</p>
15439<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#iterator.operations">issues</a> in [iterator.operations].</p>
15440<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
15441<p><b>Discussion:</b></p>
15442
15443<p><b>Addresses UK 271</b></p>
15444
15445<p>
15446<tt>next/prev</tt> return an incremented iterator without changing the value of
15447the original iterator. However, even this may invalidate an
15448<tt>InputIterator</tt>. A <tt>ForwardIterator</tt> is required to guarantee the
15449'multipass' property.
15450</p>
15451
15452<p><i>[
15453Batavia (2009-05):
15454]</i></p>
15455
15456<blockquote>
15457We agree with the proposed resolution.
15458Move to Tentatively Ready.
15459</blockquote>
15460
15461<p><i>[
154622009-07 Frankfurt
15463]</i></p>
15464
15465
15466<blockquote>
15467Moved from Tentatively Ready to Open only because the wording needs to be
15468tweaked for concepts removal.
15469</blockquote>
15470
15471<p><i>[
154722009-10-14 Daniel provided de-conceptified wording.
15473]</i></p>
15474
15475
15476<p><i>[
154772009-10 Santa Cruz:
15478]</i></p>
15479
15480
15481<blockquote>
15482Moved to Ready.
15483</blockquote>
15484
15485
15486
15487<p><b>Proposed resolution:</b></p>
15488
15489
15490<ol>
15491<li>
15492<p>
15493Change header <tt>&lt;iterator&gt;</tt> synopsis 24.3 [iterator.synopsis] as indicated:
15494</p>
15495
15496<blockquote><pre>// 24.4.4, iterator operations:
15497...
15498template &lt;class <del>Input</del><ins>Forward</ins>Iterator&gt;
15499  <del>Input</del><ins>Forward</ins>Iterator
15500  next(<del>Input</del><ins>Forward</ins>Iterator x, typename std::iterator_traits&lt;<del>Input</del><ins>Forward</ins>Iterator&gt;::difference_type n = 1);
15501</pre></blockquote>
15502</li>
15503
15504<li>
15505<p>
15506Change 24.4.4 [iterator.operations] before p.6 as indicated:
15507</p>
15508
15509<blockquote><pre>template &lt;class <del>Input</del><ins>Forward</ins>Iterator&gt;
15510  <del>Input</del><ins>Forward</ins>Iterator
15511  next(<del>Input</del><ins>Forward</ins>Iterator x, typename std::iterator_traits&lt;<del>Input</del><ins>Forward</ins>Iterator&gt;::difference_type n = 1);
15512</pre></blockquote>
15513</li>
15514</ol>
15515
15516
15517
15518
15519
15520
15521<hr>
15522<h3><a name="1030"></a>1030. Response to JP 44</h3>
15523<p><b>Section:</b> 20.8.15.5 [util.smartptr.shared.atomic] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
15524 <b>Submitter:</b> Alisdair Meredith <b>Opened:</b> 2009-03-11  <b>Last modified:</b> 2009-10-23</p>
15525<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
15526<p><b>Discussion:</b></p>
15527
15528<p><b>Addresses JP 44</b></p>
15529
15530<p>
15531The 1st parameter <tt>p</tt> and 2nd parameter <tt>v</tt> is now
15532<tt>shared_ptr&lt;T&gt;*</tt>.
15533</p>
15534<p>
15535It should be <tt>shared_ptr&lt;T&gt;&amp;</tt>, or if these are
15536<tt>shared_ptr&lt;T&gt;*</tt> then add the "<tt>p</tt> shall not be a
15537null pointer" at the requires.
15538</p>
15539
15540<p><i>[
15541Summit:
15542]</i></p>
15543
15544
15545<blockquote>
15546Agree. All of the functions need a requirement that <tt>p</tt> (or
15547<tt>v</tt>) is a pointer to a valid object.
15548</blockquote>
15549
15550<p><i>[
155512009-07 post-Frankfurt:
15552]</i></p>
15553
15554
15555<blockquote>
15556<p>
15557Lawrence explained that these signatures match the regular atomics. The
15558regular atomics must not use references because these signatures are
15559shared with C. The decision to pass shared_ptrs by pointer rather than
15560by reference was deliberate and was motivated by the principle of least
15561surprise.
15562</p>
15563<p>
15564Lawrence to write wording that requires that the pointers not be null.
15565</p>
15566</blockquote>
15567
15568<p><i>[
155692009-09-20 Lawrence provided wording:
15570]</i></p>
15571
15572
15573<blockquote>
15574<p>
15575The parameter types for atomic shared pointer access
15576were deliberately chosen to be pointers
15577to match the corresponding parameters of the atomics chapter.
15578Those in turn were deliberately chosen
15579to match C functions,
15580which do not have reference parameters.
15581</p>
15582<p>
15583We adopt the second suggestion,
15584to require that such pointers not be null.
15585</p>
15586</blockquote>
15587
15588<p><i>[
155892009-10 Santa Cruz:
15590]</i></p>
15591
15592
15593<blockquote>
15594Moved to Ready.
15595</blockquote>
15596
15597
15598
15599<p><b>Proposed resolution:</b></p>
15600<p>
15601In section "<code>shared_ptr</code> atomic access"
1560220.8.15.5 [util.smartptr.shared.atomic], add to each function the
15603following clause.
15604</p>
15605<blockquote><p>
15606<i>Requires:</i> <code>p</code> shall not be null.
15607</p></blockquote>
15608
15609
15610
15611
15612
15613<hr>
15614<h3><a name="1033"></a>1033. <tt>thread::join()</tt> effects?</h3>
15615<p><b>Section:</b> 30.3.1.5 [thread.thread.member] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
15616 <b>Submitter:</b> Alberto Ganesh Barbati <b>Opened:</b> 2009-03-12  <b>Last modified:</b> 2009-05-23</p>
15617<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#thread.thread.member">active issues</a> in [thread.thread.member].</p>
15618<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#thread.thread.member">issues</a> in [thread.thread.member].</p>
15619<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
15620<p><b>Discussion:</b></p>
15621
15622<p>
15623While looking at <tt>thread::join()</tt> I think I spotted a couple of
15624possible defects in the specifications. I could not find a previous
15625issue or NB comment about that, but I might have missed it.
15626</p>
15627
15628<p>
15629The postconditions clause for <tt>thread::join()</tt> is:
15630</p>
15631
15632<blockquote>
15633<i>Postconditions:</i> If <tt>join()</tt> throws an exception, the value
15634returned by <tt>get_id()</tt> is unchanged. Otherwise, <tt>get_id() == id()</tt>.
15635</blockquote>
15636
15637<p>
15638and the throws clause is:
15639</p>
15640
15641<blockquote>
15642<i>Throws:</i> <tt>std::system_error</tt> when the postconditions cannot be achieved.
15643</blockquote>
15644
15645<p>
15646Now... how could the postconditions <em>not</em> be achieved?
15647It's just a matter of resetting the value of <tt>get_id()</tt> or leave it
15648unchanged! I bet we can always do that. Moreover, it's a chicken-and-egg
15649problem: in order to decide whether to throw or not I depend on the
15650postconditions, but the postconditions are different in the two cases.
15651</p>
15652
15653<p>
15654I believe the throws clause should be:
15655</p>
15656
15657<blockquote>
15658<i>Throws:</i> <tt>std::system_error</tt> when the effects or postconditions
15659cannot be achieved.
15660</blockquote>
15661
15662<p>
15663as it is in <tt>detach()</tt>, or, even better, as the postcondition is
15664trivially satisfiable and to remove the circular dependency:
15665</p>
15666
15667
15668<blockquote>
15669<i>Throws:</i> <tt>std::system_error</tt> if the effects cannot be achieved.
15670</blockquote>
15671
15672<p>
15673Problem is that... ehm... <tt>join()</tt> has no "Effects" clause. Is that intentional?
15674</p>
15675
15676<p><i>[
15677See the thread starting at c++std-lib-23204 for more discussion.
15678]</i></p>
15679
15680
15681<p><i>[
15682Batavia (2009-05):
15683]</i></p>
15684
15685<blockquote>
15686<p>
15687Pete believes there may be some more general language (in frontmatter)
15688that can address this and related issues such as <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#962">962</a>.
15689</p>
15690<p>
15691Move to Open.
15692</p>
15693</blockquote>
15694
15695
15696<p><b>Proposed resolution:</b></p>
15697
15698
15699
15700
15701
15702<hr>
15703<h3><a name="1034"></a>1034. Response to UK 222</h3>
15704<p><b>Section:</b> 23.2.1 [container.requirements.general] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
15705 <b>Submitter:</b> Alisdair Meredith <b>Opened:</b> 2009-03-12  <b>Last modified:</b> 2009-10-20</p>
15706<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#container.requirements.general">active issues</a> in [container.requirements.general].</p>
15707<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#container.requirements.general">issues</a> in [container.requirements.general].</p>
15708<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
15709<p><b>Discussion:</b></p>
15710
15711<p><b>Addresses UK 222</b></p>
15712
15713<p>
15714It is not clear what purpose the Requirement tables serve in the
15715Containers clause. Are they the definition of a library Container? Or
15716simply a conventient shorthand to factor common semantics into a single
15717place, simplifying the description of each subsequent container? This
15718becomes an issue for 'containers' like <tt>array</tt>, which does not meet the
15719default-construct-to-empty requirement, or <tt>forward_list</tt> which does not
15720support the size operation. Are these components no longer containers?
15721Does that mean the remaining requirements don't apply? Or are these
15722contradictions that need fixing, despite being a clear design decision?
15723</p>
15724
15725<p>
15726Recommend:
15727</p>
15728
15729<p>
15730Clarify all the tables in 23.2 [container.requirements] are
15731there as a convenience for documentation, rather than a strict set of
15732requirements. Containers should be allowed to relax specific
15733requirements if they call attention to them in their documentation. The
15734introductory text for <tt>array</tt> should be expanded to mention a
15735default constructed <tt>array</tt> is not empty, and
15736<tt>forward_list</tt> introduction should mention it does not provide
15737the required <tt>size</tt> operation as it cannot be implemented
15738efficiently.
15739</p>
15740
15741<p><i>[
15742Summit:
15743]</i></p>
15744
15745
15746<blockquote>
15747Agree in principle.
15748</blockquote>
15749
15750<p><i>[
157512009-07 post-Frankfurt:
15752]</i></p>
15753
15754
15755<blockquote>
15756We agree in principle, but we have a timetable. This group feels that
15757the issue should be closed as NAD unless a proposed resolution is
15758submitted prior to the March 2010 meeting.
15759</blockquote>
15760
15761<p><i>[
157622009-10 Santa Cruz:
15763]</i></p>
15764
15765
15766<blockquote>
15767Looked at this and still intend to close as NAD in March
157682010 unless there is proposed wording that we like.
15769</blockquote>
15770
15771
15772
15773<p><b>Proposed resolution:</b></p>
15774
15775
15776
15777
15778
15779<hr>
15780<h3><a name="1052"></a>1052. Response to UK 281</h3>
15781<p><b>Section:</b> 24.5.1.3.5 [reverse.iter.opref] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
15782 <b>Submitter:</b> Alisdair Meredith <b>Opened:</b> 2009-03-12  <b>Last modified:</b> 2009-10-22</p>
15783<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
15784<p><b>Discussion:</b></p>
15785
15786<p><b>Addresses UK 281</b></p>
15787
15788<p>
15789The current specification for return value for <tt>reverse_iterator::operator-&gt;</tt>
15790will always be a true pointer type, but <tt>reverse_iterator</tt> supports proxy
15791iterators where the pointer type may be some kind of 'smart pointer'.
15792</p>
15793
15794<p><i>[
15795Summit:
15796]</i></p>
15797
15798
15799<blockquote>
15800<p>
15801<tt>move_iterator</tt> avoids this problem by returning a value of the wrapped
15802Iterator type.
15803study group formed to come up with a suggested resolution.
15804</p>
15805<p>
15806<tt>move_iterator</tt> solution shown in proposed wording.
15807</p>
15808</blockquote>
15809
15810<p><i>[
158112009-07 post-Frankfurt:
15812]</i></p>
15813
15814
15815<blockquote>
15816Howard to deconceptize. Move to Review after that happens.
15817</blockquote>
15818
15819<p><i>[
158202009-08-01 Howard deconceptized:
15821]</i></p>
15822
15823
15824<blockquote>
15825</blockquote>
15826
15827<p><i>[
158282009-10 Santa Cruz:
15829]</i></p>
15830
15831
15832<blockquote>
15833<p>
15834We can't think of any reason we can't just define reverse
15835iterator's pointer types to be the same as the underlying iterator's
15836pointer type, and get it by calling the right arrow directly.
15837</p>
15838<p>
15839Here is the proposed wording that was replaced:
15840</p>
15841<blockquote><pre>template &lt;class Iterator&gt; 
15842class reverse_iterator { 
15843  ...
15844  typedef <del>typename iterator_traits&lt;</del>Iterator<del>&gt;::pointer</del> pointer;
15845</pre></blockquote>
15846
15847<p>
15848Change 24.5.1.3.5 [reverse.iter.opref]:
15849</p>
15850
15851<blockquote><pre>pointer operator-&gt;() const;
15852</pre>
15853<blockquote>
15854<i>Returns:</i>
15855<blockquote><pre><del>&amp;(operator*());</del>
15856<ins>this-&gt;tmp = current;</ins>
15857<ins>--this-&gt;tmp;</ins>
15858<ins>return this-&gt;tmp;</ins>
15859</pre></blockquote>
15860</blockquote>
15861</blockquote>
15862</blockquote>
15863
15864
15865
15866<p><b>Proposed resolution:</b></p>
15867<p>
15868Change 24.5.1.3.5 [reverse.iter.opref]:
15869</p>
15870
15871<blockquote><pre>pointer operator-&gt;() const;
15872</pre>
15873<blockquote>
15874<i>Returns:</i>
15875<blockquote><pre><del>&amp;(operator*());</del>
15876<ins>deref_tmp = current;
15877--deref_tmp;
15878return deref_tmp::operator-&gt;();</ins>
15879</pre></blockquote>
15880</blockquote>
15881</blockquote>
15882
15883
15884
15885
15886
15887
15888
15889
15890
15891<hr>
15892<h3><a name="1056"></a>1056. Must all Engines and Distributions be Streamable?</h3>
15893<p><b>Section:</b> 26.5 [rand] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#NAD">Tentatively NAD</a>
15894 <b>Submitter:</b> Alisdair Meredith <b>Opened:</b> 2009-03-12  <b>Last modified:</b> 2009-11-03</p>
15895<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#rand">issues</a> in [rand].</p>
15896<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Tentatively%20NAD">Tentatively NAD</a> status.</p>
15897<p><b>Discussion:</b></p>
15898
15899<p>
15900Both the concepts <tt>RandomNumberEngine</tt> and <tt>RandomNumberDistribution</tt> have
15901requirements to be <tt>InputStreamable</tt> and <tt>OutputStreamable</tt>.
15902</p>
15903<p>
15904I have no problems leaving the WP in an inconsistent state on the best-faith
15905assumption these concepts will be provided later, however disagree with the
15906proposers that these constraints are not separable, orthogonal to the basic
15907concepts of generating random number distributions.
15908</p>
15909<p>
15910These constraints should be dropped, and applied to specific algorithms as
15911needed.
15912</p>
15913<p>
15914If a more refined concept (certainly deemed useful by the proposers) is
15915proposed there is no objection, but the basic concept should not require
15916persistence via streaming.
15917</p>
15918
15919<p><i>[
15920Batavia (2009-05):
15921]</i></p>
15922
15923<blockquote>
15924Move to Open.
15925</blockquote>
15926
15927<p><i>[
159282009-05-31 Alisdair adds:
15929]</i></p>
15930
15931
15932<blockquote>
15933<p>
15934Working on constraining the stream iterators, I have a few more observations
15935to make on the concepts proposed while constraining the random number
15936facility.
15937</p>
15938<p>
15939While I still believe the concerns are orthogonal, I don't believe the
15940existing constraints go far enough either!  The goal we want to achieve is
15941not that a <tt>RandomNumberEngine</tt> / <tt>RandomNumberDistribution</tt> supports the stream
15942operators, but that it is <tt>Serializable</tt>.  I.e. there is a relationship
15943between the insert and extract operations that guarantees to restore the
15944state of the original object.  This implies a coupling of the concepts
15945together in a broader concept (<tt>Serializable</tt>) with at least one axiom to
15946assert the semantics.
15947</p>
15948<p>
15949One problem is that <tt>istream</tt> and <tt>ostream</tt> may be fundamentally different
15950types, although we can hook a relation if we are prepared to drop down to
15951the <tt>char</tt> type and <tt>char_traits</tt> template parameters.  Doing so ties us to a
15952form of serialization that demands implementation via the std iostreams
15953framework, which seems overly prescriptive.  I believe the goal is generally
15954to support serialization without regard to how it is expressed - although
15955this is getting even more inventive in terms of concepts we do not have
15956today.
15957</p>
15958</blockquote>
15959
15960<p><i>[
159612009-11-03 Alisdair adds:
15962]</i></p>
15963
15964
15965<blockquote>
15966<p>
15967I can't find the record in the wiki minutes, but it was agreed at both
15968Frankfurt and Santa Cruz that this issue is NAD.
15969</p>
15970<p>
15971The agreement in SC was that I would provide you with the rationale (see
15972below) to include when moving to NAD.
15973</p>
15974</blockquote>
15975
15976<p><i>[
159772009-11-03 Howard adds:
15978]</i></p>
15979
15980
15981<blockquote>
15982Moved to Tentatively NAD after 5 positive votes on c++std-lib.
15983</blockquote>
15984
15985
15986<p><b>Proposed resolution:</b></p>
15987
15988
15989<p><b>Rationale:</b></p>
15990<p>
15991The issue suggests a more refined concept should be used if we want to
15992require streaming, to separate concerns from the basic
15993<tt>RandomNumberEngine</tt> behaviour.  In Frankfurt it was observed
15994that <tt>RandomNumberEngine</tt> <em>is</em> that more refined concept,
15995and the basic concept used in the framework is
15996<tt>UniformRandomNumberGenerator</tt>, which it refines.
15997</p>
15998
15999<p>
16000We concur, and expect this to have no repurcussions re-writing this
16001clause now concepts are removed.
16002</p>
16003
16004
16005
16006
16007
16008<hr>
16009<h3><a name="1068"></a>1068. class random_device should be movable</h3>
16010<p><b>Section:</b> 26.5.6 [rand.device] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
16011 <b>Submitter:</b> Alisdair Meredith <b>Opened:</b> 2009-03-18  <b>Last modified:</b> 2009-10-26</p>
16012<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#rand.device">issues</a> in [rand.device].</p>
16013<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
16014<p><b>Discussion:</b></p>
16015
16016<p>
16017class <tt>random_device</tt> should be movable.
16018</p>
16019
16020<p><i>[
16021Batavia (2009-05):
16022]</i></p>
16023
16024<blockquote>
16025Move to Open, and recommend this issue be deferred until after the next
16026Committee Draft is issued.
16027</blockquote>
16028
16029<p><i>[
160302009-10 post-Santa Cruz:
16031]</i></p>
16032
16033
16034<blockquote>
16035Leave open. Walter to provide drafting as part of his planned paper.
16036</blockquote>
16037
16038
16039
16040<p><b>Proposed resolution:</b></p>
16041
16042
16043
16044
16045
16046<hr>
16047<h3><a name="1069"></a>1069. class seed_seq should support efficient move operations</h3>
16048<p><b>Section:</b> 26.5.7.1 [rand.util.seedseq] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
16049 <b>Submitter:</b> Alisdair Meredith <b>Opened:</b> 2009-03-18  <b>Last modified:</b> 2009-10-26</p>
16050<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#rand.util.seedseq">issues</a> in [rand.util.seedseq].</p>
16051<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
16052<p><b>Discussion:</b></p>
16053
16054<p>
16055class <tt>seed_seq</tt> should support efficient move operations.
16056</p>
16057
16058<p><i>[
16059Batavia (2009-05):
16060]</i></p>
16061
16062<blockquote>
16063Move to Open, and recommend this issue be deferred until after the next
16064Committee Draft is issued.
16065</blockquote>
16066
16067<p><i>[
160682009-10 post-Santa Cruz:
16069]</i></p>
16070
16071
16072<blockquote>
16073Leave open. Walter to provide drafting as part of his planned paper.
16074</blockquote>
16075
16076
16077
16078<p><b>Proposed resolution:</b></p>
16079
16080
16081
16082
16083
16084<hr>
16085<h3><a name="1071"></a>1071. is_bind_expression should derive from integral_constant&lt;bool&gt;</h3>
16086<p><b>Section:</b> 20.7.11.1.1 [func.bind.isbind] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Tentatively Ready</a>
16087 <b>Submitter:</b> Alisdair Meredith <b>Opened:</b> 2009-03-19  <b>Last modified:</b> 2009-10-26</p>
16088<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Tentatively%20Ready">Tentatively Ready</a> status.</p>
16089<p><b>Discussion:</b></p>
16090
16091<p>
16092Class template is_bind_expression 20.7.11.1.1 [func.bind.isbind]:
16093</p>
16094
16095<blockquote><pre>namespace std {
16096  template&lt;class T&gt; struct is_bind_expression {
16097    static const bool value = see below;
16098  };
16099}
16100</pre></blockquote>
16101<p>
16102<tt>is_bind_expression</tt> should derive from <tt>std::integral_constant&lt;bool&gt;</tt> like
16103other similar trait types.
16104</p>
16105
16106<p><i>[
16107Daniel adds:
16108]</i></p>
16109
16110<blockquote>
16111We need the same thing for the trait <tt>is_placeholder</tt> as well.
16112</blockquote>
16113<p><i>[
161142009-03-22 Daniel provided wording.
16115]</i></p>
16116
16117
16118<p><i>[
16119Batavia (2009-05):
16120]</i></p>
16121
16122<blockquote>
16123<p>
16124We recommend this be deferred until after the next Committee Draft is issued.
16125</p>
16126<p>
16127Move to Open.
16128</p>
16129</blockquote>
16130
16131<p><i>[
161322009-05-31 Peter adds:
16133]</i></p>
16134
16135
16136<blockquote>
16137<p>
16138I am opposed to the proposed resolution and to the premise of the issue
16139in general. The traits's default definitions should NOT derive from
16140<tt>integral_constant</tt>, because this is harmful, as it misleads people into
16141thinking that <tt>is_bind_expression&lt;E&gt;</tt> always derives from
16142<tt>integral_constant</tt>, whereas it may not.
16143</p>
16144<p>
16145<tt>is_bind_expression</tt> and <tt>is_placeholder</tt> allow user
16146specializations, and in fact, this is their primary purpose. Such user
16147specializations may not derive from <tt>integral_constant</tt>, and the
16148places where <tt>is_bind_expression</tt> and <tt>is_placeholder</tt> are
16149used intentionally do not require such derivation.
16150</p>
16151<p>
16152The long-term approach here is to switch to
16153<tt>BindExpression&lt;E&gt;</tt> and <tt>Placeholder&lt;P&gt;</tt>
16154explicit concepts, of course, but until that happens, I say leave them
16155alone.
16156</p>
16157</blockquote>
16158
16159<p><i>[
161602009-10 post-Santa Cruz:
16161]</i></p>
16162
16163
16164<blockquote>
16165Move to Tentatively Ready.  We are comfortable with requiring user specializations
16166to derive from <tt>integral_constant</tt>.
16167</blockquote>
16168
16169
16170
16171<p><b>Proposed resolution:</b></p>
16172<ol>
16173<li>
16174<p>
16175In 20.7.11.1.1 [func.bind.isbind] change as indicated:
16176</p>
16177<blockquote><pre>namespace std {
16178 template&lt;class T&gt; struct is_bind_expression <ins>: integral_constant&lt;bool, <i>see below</i>&gt; { };</ins><del>{
16179   static const bool value = <i>see below</i>;
16180 };</del>
16181}
16182</pre></blockquote>
16183</li>
16184<li>
16185<p>
16186In 20.7.11.1.1 [func.bind.isbind]/2 change as indicated:
16187</p>
16188<blockquote><pre><del>static const bool value;</del>
16189</pre>
16190<blockquote>
16191-2- <del><tt>true</tt> if <tt>T</tt> is a type returned from <tt>bind</tt>, <tt>false</tt> otherwise.</del>
16192  <ins>If <tt>T</tt> is a type returned from <tt>bind</tt>, <tt>is_bind_expression&lt;T&gt;</tt> shall
16193be publicly derived from
16194        <tt>integral_constant&lt;bool, true&gt;</tt>, otherwise it shall be
16195publicly derived from
16196          <tt>integral_constant&lt;bool, false&gt;</tt>.</ins>
16197</blockquote>
16198</blockquote>
16199</li>
16200<li>
16201<p>
16202In 20.7.11.1.2 [func.bind.isplace] change as indicated:
16203</p>
16204<blockquote><pre>namespace std {
16205 template&lt;class T&gt; struct is_placeholder <ins>: integral_constant&lt;int, <i>see below</i>&gt; { };</ins><del>{
16206   static const int value = <i>see below</i>;
16207 };</del>
16208}
16209</pre></blockquote>
16210</li>
16211<li>
16212<p>
16213In 20.7.11.1.2 [func.bind.isplace]/2 change as indicated:
16214</p>
16215<blockquote><pre><del>static const int value;</del>
16216</pre>
16217<blockquote>
16218-2- <del>value is <tt>J</tt> if <tt>T</tt> is the type of <tt>std::placeholders::_J</tt>, 0 otherwise.</del>
16219  <ins>If <tt>T</tt> is the type of <tt>std::placeholders::_J</tt>, <tt>is_placeholder&lt;T&gt;</tt>
16220shall be publicly
16221          derived from <tt>integral_constant&lt;int, J&gt;</tt> otherwise it shall
16222be publicly derived
16223          from <tt>integral_constant&lt;int, 0&gt;</tt>.</ins>
16224</blockquote>
16225</blockquote>
16226</li>
16227</ol>
16228
16229
16230
16231
16232
16233<hr>
16234<h3><a name="1076"></a>1076. unary/binary_negate need constraining and move support</h3>
16235<p><b>Section:</b> 20.7.10 [negators] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
16236 <b>Submitter:</b> Alisdair Meredith <b>Opened:</b> 2009-03-20  <b>Last modified:</b> 2009-10-26</p>
16237<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
16238<p><b>Discussion:</b></p>
16239<p>
16240The class templates <tt>unary/binary_negate</tt> need constraining and move support.
16241</p>
16242<p>
16243Ideally these classes would be deprecated, allowing <tt>unary/binary_function</tt> to
16244also be deprecated.  However, until a generic negate adaptor is introduced
16245that can negate any <tt>Callable</tt> type, they must be supported so should be
16246constrained.  Likewise, they should be movable, and support adopting a
16247move-only predicate type.
16248</p>
16249<p>
16250In order to preserve ABI compatibility, new rvalue overloads are supplied in
16251preference to changing the existing pass-by-const-ref to pass-by-value.
16252</p>
16253<p>
16254Do not consider the issue of forwarding mutable lvalues at this point,
16255although remain open to another issue on the topic.
16256</p>
16257
16258<p><i>[
162592009-05-01 Daniel adds:
16260]</i></p>
16261
16262<blockquote>
16263<p>
16264IMO the currently proposed resolution needs some updates
16265because it is ill-formed at several places:
16266</p>
16267
16268<ol>
16269<li>
16270<p>
16271In concept AdaptableUnaryFunction change
16272</p>
16273<blockquote><pre>typename X::result_type;
16274typename X::argument_type;
16275</pre></blockquote>
16276<p>
16277to
16278</p>
16279<blockquote><pre>Returnable result_type = typename X::result_type;
16280typename argument_type = typename X::argument_type;
16281</pre></blockquote>
16282<p>
16283[The replacement "Returnable result_type" instead of "typename
16284result_type" is non-editorial, but maybe you prefer that as well]
16285</p>
16286</li>
16287<li>
16288<p>
16289In concept AdaptableBinaryFunction change
16290</p>
16291<blockquote><pre>typename X::result_type;
16292typename X::first_argument_type;
16293typename X::second_argument_type;
16294</pre></blockquote>
16295<p>
16296to
16297</p>
16298<blockquote><pre>Returnable result_type = typename X::result_type;
16299typename first_argument_type = typename X::first_argument_type;
16300typename second_argument_type = typename X::second_argument_type;
16301</pre></blockquote>
16302<p>
16303[The replacement "Returnable result_type" instead of "typename
16304result_type" is non-editorial, but maybe you prefer that as well.]
16305</p>
16306</li>
16307
16308<li>
16309<p>
16310In class unary/binary_function
16311</p>
16312<ol type="a">
16313<li>
16314I suggest to change "ReturnType" to "Returnable" in both cases.
16315</li>
16316<li>
16317I think you want to replace the remaining occurrences of "Predicate" by "P"
16318(in both classes in copy/move from a predicate)
16319</li>
16320</ol>
16321</li>
16322<li>
16323<p>
16324I think you need to change the proposed signatures of not1 and not2, because
16325they would still remain unconstrained: To make them constrained at least a
16326single requirement needs to be added to enable requirement implication. This
16327could be done via a dummy ("requires True&lt;true&gt;") or just explicit as follows:
16328</p>
16329<ol type="a">
16330<li>
16331<blockquote><pre>template &lt;AdaptableUnaryFunction P&gt;
16332requires Predicate&lt; P, P::argument_type&gt;
16333unary_negate&lt;P&gt; not1(const P&amp;&amp; pred);
16334template &lt;AdaptableUnaryFunction P&gt;
16335requires Predicate&lt; P, P::argument_type &gt;
16336unary_negate&lt;P&gt; not1(P&amp;&amp; pred);
16337</pre>
16338<blockquote>
16339-3- Returns: unary_negate&lt;P&gt;(pred).
16340</blockquote>
16341</blockquote>
16342<p>
16343[Don't we want a move call for the second overload as in
16344</p>
16345<blockquote><pre>unary_negate&lt;P&gt;(std::move(pred))
16346</pre></blockquote>
16347<p>
16348in the Returns clause ?]
16349</p>
16350</li>
16351<li>
16352<pre>template &lt;AdaptableBinaryFunction P&gt;
16353requires Predicate&lt; P, P::first_argument_type, P::second_argument_type &gt;
16354binary_negate&lt;P&gt; not2(const P&amp; pred);
16355template &lt;AdaptableBinaryFunction P&gt;
16356requires Predicate&lt; P, P::first_argument_type, P::second_argument_type &gt;
16357binary_negate&lt;P&gt; not2(P&amp;&amp; pred);
16358</pre>
16359<p>
16360-5- Returns: binary_negate&lt;P&gt;(pred).
16361</p>
16362<p>
16363[Don't we want a move call for the second overload as in
16364</p>
16365<blockquote><pre>binary_negate&lt;P&gt;(std::move(pred))
16366</pre></blockquote>
16367<p>
16368in the Returns clause ?]
16369</p>
16370</li>
16371</ol>
16372</li>
16373</ol>
16374</blockquote>
16375
16376<p><i>[
16377Batavia (2009-05):
16378]</i></p>
16379
16380<blockquote>
16381<p>
16382There is concern that complicating the solution
16383to preserve the ABI seems unnecessary,
16384since we're not in general preserving the ABI.
16385</p>
16386<p>
16387We would prefer a separate paper consolidating all Clause 20
16388issues that are for the purpose of providing constrained versions
16389of the existing facilities.
16390</p>
16391<p>
16392Move to Open.
16393</p>
16394</blockquote>
16395
16396<p><i>[
163972009-10 post-Santa Cruz:
16398]</i></p>
16399
16400
16401<blockquote>
16402Leave open pending the potential move constructor paper. Note that
16403we consider the "constraining" part NAD Concepts.
16404</blockquote>
16405
16406
16407
16408<p><b>Proposed resolution:</b></p>
16409<p>
16410Add new concepts where appropriate::
16411</p>
16412
16413<blockquote><pre>auto concept AdaptableUnaryFunction&lt; typename X &gt; {
16414  typename X::result_type;
16415  typename X::argument_type;
16416}
16417
16418auto concept AdaptableBinaryFunction&lt; typename X &gt; {
16419  typename X::result_type;
16420  typename X::first_argument_type;
16421  typename X::second_argument_type;
16422}
16423</pre></blockquote>
16424
16425<p>
16426Revise as follows:
16427</p>
16428
16429<p>
16430Base 20.7.3 [base] (Only change is constrained Result)
16431</p>
16432
16433<blockquote>
16434<p>
16435-1-  The following classes are provided to simplify the typedefs of the
16436argument and result types:
16437</p>
16438<pre>namespace std {
16439  template &lt;class Arg, <del>class</del> <ins>ReturnType</ins> Result&gt;
16440  struct unary_function {
16441     typedef Arg    argument_type;
16442     typedef Result result_type;
16443  };
16444
16445  template &lt;class Arg1, class Arg2, <del>class</del> <ins>ReturnType</ins> Result&gt;
16446  struct binary_function {
16447     typedef Arg1   first_argument_type;
16448     typedef Arg2   second_argument_type;
16449     typedef Result result_type;
16450  };
16451}
16452</pre></blockquote>
16453
16454<p>
16455Negators 20.7.10 [negators]:
16456</p>
16457
16458<blockquote>
16459<p>
16460-1- Negators <tt>not1</tt> and <tt>not2</tt> take a unary and a binary predicate,
16461respectively, and return their complements (5.3.1).
16462</p>
16463
16464<pre>template &lt;<del>class</del> <ins>AdaptableUnaryFunction</ins> P<del>redicate</del>&gt;
16465  <ins>requires Predicate&lt; P, P::argument_type &gt;</ins>
16466  class unary_negate
16467    : public unary_function&lt;<del>typename</del> P<del>redicate</del>::argument_type,bool&gt; {
16468  public:
16469    <ins>unary_negate(const unary_negate &amp; ) = default;</ins>
16470    <ins>unary_negate(unary_negate &amp;&amp; );</ins>
16471
16472    <ins>requires CopyConstructible&lt; P &gt;</ins>
16473       explicit unary_negate(const Predicate&amp; pred); 
16474    <ins>requires MoveConstructible&lt; P &gt;
16475       explicit unary_negate(Predicate &amp;&amp; pred);</ins>
16476
16477    bool operator()(const <del>typename</del> P<del>redicate</del>::argument_type&amp; x) const;
16478  };
16479</pre>
16480<blockquote>
16481-2 <tt>operator()</tt> returns <tt>!pred(x)</tt>.
16482</blockquote>
16483
16484<pre>template &lt;class Predicate&gt;
16485  unary_negate&lt;Predicate&gt; not1(const Predicate&amp;amp; pred);
16486<ins>template &lt;class Predicate&gt;
16487  unary_negate&lt;Predicate&gt; not1(Predicate&amp;&amp; pred);</ins>
16488</pre>
16489<blockquote>
16490-3-  <i>Returns:</i> <tt>unary_negate&lt;Predicate&gt;(pred)</tt>.
16491</blockquote>
16492
16493<pre>template &lt;<del>class</del> <ins>AdaptableBinaryFunction</ins> P<del>redicate</del> &gt;
16494  <ins>requires Predicate&lt; P, P::first_argument_type, P::second_argument_type &gt;</ins>
16495  class binary_negate
16496    : public binary_function&lt;<del>typename</del> P<del>redicate</del>::first_argument_type,
16497                              <del>typename</del> P<del>redicate</del>::second_argument_type, bool&gt; {
16498  public:
16499    <ins>biary_negate(const binary_negate &amp; ) = default;</ins>
16500    <ins>binary_negate(binary_negate &amp;&amp; );</ins>
16501
16502    <ins>requires CopyConstructible&lt; P &gt;</ins>
16503       explicit binary_negate(const Predicate&amp; pred);
16504    <ins>requires MoveConstructible&lt; P &gt;
16505       explicit binary_negate(const Predicate&amp; pred);</ins>
16506
16507    bool operator()(const <del>typename</del> P<del>redicate</del>::first_argument_type&amp; x,
16508                    const <del>typename</del> P<del>redicate</del>::second_argument_type&amp; y) const;
16509  };
16510</pre>
16511<blockquote>
16512-4- <tt>operator()</tt> returns <tt>!pred(x,y)</tt>.
16513</blockquote>
16514
16515<pre>template &lt;class Predicate&gt;
16516  binary_negate&lt;Predicate&gt; not2(const Predicate&amp; pred);
16517<ins>template &lt;class Predicate&gt;
16518  binary_negate&lt;Predicate&gt; not2(Predicate&amp;&amp; pred);</ins>
16519</pre>
16520
16521<blockquote>
16522-5- <i>Returns:</i> <tt>binary_negate&lt;Predicate&gt;(pred)</tt>.
16523</blockquote>
16524</blockquote>
16525
16526
16527
16528
16529
16530
16531<hr>
16532<h3><a name="1079"></a>1079. UK-265: <code>RandomAccessIterator</code>'s <code>operator-</code> has nonsensical effects clause</h3>
16533<p><b>Section:</b> 24.2.5 [random.access.iterators] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
16534 <b>Submitter:</b> Doug Gregor <b>Opened:</b> 2009-03-20  <b>Last modified:</b> 2009-10-23</p>
16535<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#random.access.iterators">issues</a> in [random.access.iterators].</p>
16536<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
16537<p><b>Discussion:</b></p>
16538<p><b>Addresses UK 265</b></p>
16539
16540<p>UK-265:</p>
16541<p>
16542This effects clause is nonesense. It looks more like an axiom stating
16543equivalence, and certainly an effects clause cannot change the state of
16544two arguments passed by const reference
16545</p>
16546
16547<p><i>[
165482009-09-18 Alisdair adds:
16549]</i></p>
16550
16551
16552<blockquote>
16553<p>
16554For random access iterators, the definitions of <tt>(b-a)</tt> and
16555<tt>(a&lt;b)</tt> are circular:
16556</p>
16557
16558<p>
16559From table Table 104 -- Random access iterator requirements:
16560</p>
16561
16562<blockquote><pre>b - a :==&gt;  (a &lt; b) ? distance(a,b) : -distance(b,a)
16563
16564a &lt; b :==&gt;  b - a &gt; 0
16565</pre></blockquote>
16566</blockquote>
16567
16568<p><i>[
165692009-10 Santa Cruz:
16570]</i></p>
16571
16572
16573<blockquote>
16574Moved to Ready.
16575</blockquote>
16576
16577
16578
16579<p><b>Proposed resolution:</b></p>
16580
16581<p>Modify 24.2.5 [random.access.iterators]p7-9 as follows:</p>
16582
16583<blockquote><pre>difference_type operator-(const X&amp; a, const X&amp; b);
16584</pre>
16585<ol start="7">
16586  <li><i>Precondition</i>: there exists a value <code>n</code> of
16587  <code>difference_type</code> such that <code>a == b + n</code>.</li>
16588  <li><del><i>Effects</i>: <code>b == a + (b - a)</code></del></li>
16589  <li><i>Returns</i>: <del><code>(a &lt; b) ? distance(a,b) :
16590  -distance(b,a)</code></del><ins><code>n</code></ins></li>
16591</ol>
16592</blockquote>
16593
16594
16595
16596
16597
16598<hr>
16599<h3><a name="1089"></a>1089. Response to JP 76</h3>
16600<p><b>Section:</b> 30 [thread] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
16601 <b>Submitter:</b> Howard Hinnant <b>Opened:</b> 2009-03-22  <b>Last modified:</b> 2009-10-23</p>
16602<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#thread">issues</a> in [thread].</p>
16603<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
16604<p><b>Discussion:</b></p>
16605<p><b>Addresses JP 76</b></p>
16606
16607<p>
16608A description for "Throws: Nothing." are not unified.
16609</p>
16610
16611<p>
16612At the part without throw, "Throws: Nothing." should be described.
16613</p>
16614
16615<p>
16616Add "Throws: Nothing." to the following.
16617</p>
16618
16619<ul>
16620<li>
1662130.3.1.6 [thread.thread.static] p1
16622</li>
16623<li>
1662430.4.3.1 [thread.lock.guard] p4
16625</li>
16626<li>
1662730.4.3.2.1 [thread.lock.unique.cons] p6
16628</li>
16629<li>
1663030.5.1 [thread.condition.condvar] p7 and p8
16631</li>
16632<li>
1663330.5.2 [thread.condition.condvarany] p6, p7, p19, p21 and p25
16634</li>
16635</ul>
16636
16637<p><i>[
16638Summit:
16639]</i></p>
16640
16641<blockquote>
16642Pass on to editor.
16643</blockquote>
16644
16645<p><i>[
16646Post Summit:  Editor declares this non-editorial.
16647]</i></p>
16648
16649
16650<p><i>[
166512009-08-01 Howard provided wording:
16652]</i></p>
16653
16654
16655<blockquote>
16656
16657<p>
16658The definition of "<i>Throws:</i> Nothing." that I added is probably going to
16659be controversial, but I beg you to consider it seriously.
16660</p>
16661
16662<blockquote>
16663<p>
16664In C++ there are three "flow control" options for a function:
16665</p>
16666
16667<ol>
16668<li>
16669It can return, either with a value, or with <tt>void</tt>.
16670</li>
16671<li>
16672It can call a function which never returns, such as <tt>std::exit</tt> or
16673<tt>std::terminate</tt>.
16674</li>
16675<li>
16676It can throw an exception.
16677</li>
16678</ol>
16679
16680The above list can be abbreviated with:
16681
16682<ol>
16683<li><b>R</b>eturns.</li>
16684<li><b>E</b>nds program.</li>
16685<li><b>T</b>hrows exception.</li>
16686</ol>
16687
16688<p>
16689In general a function can have the behavior of any of these 3, or any combination
16690of any of these three, depending upon run time data.
16691</p>
16692
16693<ol>
16694<li><b>R</b></li>
16695<li><b>E</b></li>
16696<li><b>T</b></li>
16697<li><b>RE</b></li>
16698<li><b>RT</b></li>
16699<li><b>ET</b></li>
16700<li><b>RET</b></li>
16701</ol>
16702
16703<p>
16704A function with no throw spec, and no documentation, is in general a <b>RET</b>
16705function.  It may return, it may end the program, or it may throw.  When we
16706specify a function with an empty throw spec:
16707</p>
16708
16709<blockquote><pre>void f() throw();
16710</pre></blockquote>
16711
16712<p>
16713We are saying that <tt>f()</tt> is an <b>RE</b> function:  It may return or end
16714the program, but it will not throw.
16715</p>
16716
16717<p>
16718I posit that there are very few places in the library half of the standard
16719where we intend for functions to be able to end the program (call <tt>terminate</tt>).
16720And none of those places where we do say <tt>terminate</tt> could be called,
16721do we currently say "<i>Throws:</i> Nothing.".
16722</p>
16723
16724<p>
16725I believe that if we define "<i>Throws:</i> Nothing." to mean <b>R</b>,
16726we will both clarify many, many places in the standard, <em>and</em> give us a
16727good rationale for choosing between "<i>Throws:</i> Nothing." (<b>R</b>)
16728and <tt>throw()</tt> (<b>RE</b>) in the future.  Indeed, this may give us motivation
16729to change several <tt>throw()</tt>s to "<i>Throws:</i> Nothing.".
16730</p>
16731</blockquote>
16732
16733<p>
16734I did not add the following changes as JP 76 requested as I believe we want to
16735allow these functions to throw:
16736</p>
16737
16738<blockquote>
16739<p>
16740Add a paragraph under 30.4.3.1 [thread.lock.guard] p4:
16741</p>
16742
16743<blockquote><pre>explicit lock_guard(mutex_type&amp; m);
16744</pre>
16745
16746<p><ins>
16747<i>Throws:</i> Nothing.
16748</ins></p>
16749</blockquote>
16750
16751<p>
16752Add a paragraph under 30.4.3.2.1 [thread.lock.unique.cons] p6:
16753</p>
16754
16755<blockquote><pre>explicit unique_lock(mutex_type&amp; m);
16756</pre>
16757
16758<p><ins>
16759<i>Throws:</i> Nothing.
16760</ins></p>
16761</blockquote>
16762
16763<p>
16764Add a paragraph under 30.5.2 [thread.condition.condvarany] p19, p21 and p25:
16765</p>
16766
16767<blockquote><pre>template &lt;class Lock, class Rep, class Period&gt; 
16768  bool wait_for(Lock&amp; lock, const chrono::duration&lt;Rep, Period&gt;&amp; rel_time);
16769</pre>
16770
16771<p><ins>
16772<i>Throws:</i> Nothing.
16773</ins></p>
16774</blockquote>
16775
16776<blockquote><pre>template &lt;class Lock, class Duration, class Predicate&gt; 
16777  bool wait_until(Lock&amp; lock, const chrono::time_point&lt;Clock, Duration&gt;&amp; rel_time, Predicate pred);
16778</pre>
16779
16780<p><ins>
16781<i>Throws:</i> Nothing.
16782</ins></p>
16783</blockquote>
16784
16785<blockquote><pre>template &lt;class Lock, class Rep, class Period, class Predicate&gt; 
16786  bool wait_for(Lock&amp; lock, const chrono::duration&lt;Rep, Period&gt;&amp; rel_time, Predicate pred);
16787</pre>
16788
16789<p><ins>
16790<i>Throws:</i> Nothing.
16791</ins></p>
16792</blockquote>
16793
16794</blockquote>
16795
16796</blockquote>
16797
16798<p><i>[
167992009-10 Santa Cruz:
16800]</i></p>
16801
16802
16803<blockquote>
16804Defer pending further developments with exception restriction annotations.
16805</blockquote>
16806
16807
16808
16809<p><b>Proposed resolution:</b></p>
16810<p>
16811Add a paragraph after 17.5.1.4 [structure.specifications] p4:
16812</p>
16813
16814<blockquote>
16815<p>
16816-3- Descriptions of function semantics contain the following elements
16817(as appropriate):<sup>158</sup>
16818</p>
16819<ul>
16820<li>...</li>
16821<li>
16822<i>Throws:</i> any exceptions thrown by the function, and the conditions
16823that would cause the exception
16824</li>
16825<li>...</li>
16826</ul>
16827
16828<p>
16829-4- For non-reserved replacement and handler functions, ...
16830</p>
16831
16832<p><ins>
16833A "<i>Throws:</i> Nothing." element indicates that the function shall
16834return ordinarily, and not exit via an exception.  This element also
16835indicates that the function <em>shall</em> return. [<i>Note:</i> This
16836differs from an empty throw specification which may cause a function to
16837call <tt>unexpected</tt> and subsequently <tt>terminate</tt>. &#8212;
16838<i>end note</i>]
16839</ins></p>
16840</blockquote>
16841
16842<p>
16843Add a paragraph under 30.3.1.6 [thread.thread.static] p1:
16844</p>
16845
16846<blockquote><pre>unsigned hardware_concurrency();
16847</pre>
16848
16849<p>
16850-1- <i>Returns:</i> ...
16851</p>
16852
16853<p><ins>
16854<i>Throws:</i> Nothing.
16855</ins></p>
16856</blockquote>
16857
16858<p>
16859Add a paragraph under 30.5.1 [thread.condition.condvar] p7 and p8:
16860</p>
16861
16862<blockquote>
16863<p>
16864<i>[Informational, not to be incluced in the WP: The POSIX spec allows only:</i>
16865</p>
16866<dl>
16867<dt><i>[EINVAL]</i></dt>
16868<dd><i>The value <tt>cond</tt> does not refer to an initialized condition variable. &#8212; end informational]</i></dd>
16869</dl>
16870
16871<pre>void notify_one();
16872</pre>
16873
16874<p>
16875-7- <i>Effects:</i> ...
16876</p>
16877
16878<p><ins>
16879<i>Throws:</i> Nothing.
16880</ins></p>
16881</blockquote>
16882
16883<blockquote><pre>void notify_all();
16884</pre>
16885
16886<p>
16887-8- <i>Effects:</i> ...
16888</p>
16889
16890<p><ins>
16891<i>Throws:</i> Nothing.
16892</ins></p>
16893</blockquote>
16894
16895
16896<p>
16897Add a paragraph under 30.5.2 [thread.condition.condvarany] p6 and p7:
16898</p>
16899
16900<blockquote>
16901<pre>void notify_one();
16902</pre>
16903
16904<p>
16905-6- <i>Effects:</i> ...
16906</p>
16907
16908<p><ins>
16909<i>Throws:</i> Nothing.
16910</ins></p>
16911</blockquote>
16912
16913<blockquote><pre>void notify_all();
16914</pre>
16915
16916<p>
16917-7- <i>Effects:</i> ...
16918</p>
16919
16920<p><ins>
16921<i>Throws:</i> Nothing.
16922</ins></p>
16923</blockquote>
16924
16925
16926
16927
16928
16929
16930
16931<hr>
16932<h3><a name="1090"></a>1090. Missing description of <tt>packaged_task</tt> member <tt>swap</tt>,  missing non-member <tt>swap</tt></h3>
16933<p><b>Section:</b> 30.6.10 [futures.task] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Tentatively Ready</a>
16934 <b>Submitter:</b> Daniel Kr�gler <b>Opened:</b> 2009-03-22  <b>Last modified:</b> 2009-10-26</p>
16935<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Tentatively%20Ready">Tentatively Ready</a> status.</p>
16936<p><b>Discussion:</b></p>
16937<p>
16938Class template <tt>packaged_task</tt> in 30.6.10 [futures.task] shows a member <tt>swap</tt>
16939declaration, but misses to
16940document it's effects (No prototype provided). Further on this class
16941misses to provide a non-member
16942swap.
16943</p>
16944
16945<p><i>[
16946Batavia (2009-05):
16947]</i></p>
16948
16949<blockquote>
16950<p>
16951Alisdair notes that paragraph 2 of the proposed resolution has already been
16952applied in the current Working Draft.
16953</p>
16954<p>
16955We note a pending <tt>future</tt>-related paper by Detlef;
16956we would like to wait for this paper before proceeding.
16957</p>
16958<p>
16959Move to Open.
16960</p>
16961</blockquote>
16962
16963<p><i>[
169642009-05-24 Daniel removed part 2 of the proposed resolution.
16965]</i></p>
16966
16967
16968<p><i>[
169692009-10 post-Santa Cruz:
16970]</i></p>
16971
16972
16973<blockquote>
16974Move to Tentatively Ready, removing bullet 3 from the proposed
16975resolution but keeping the other two bullets.
16976</blockquote>
16977
16978
16979
16980<p><b>Proposed resolution:</b></p>
16981<ol>
16982<li>
16983<p>
16984In 30.6.10 [futures.task], immediately after the definition of class
16985template packaged_task add:
16986</p>
16987<blockquote><pre><ins>
16988template&lt;class R, class... Argtypes&gt;
16989void swap(packaged_task&lt;R(ArgTypes...)&gt;&amp;, packaged_task&lt;R(ArgTypes...)&gt;&amp;);
16990</ins>
16991</pre></blockquote>
16992</li>
16993</ol>
16994
16995<ol start="4">
16996
16997<li>
16998<p>
16999At the end of 30.6.10 [futures.task] (after p. 20), add add the following
17000prototype description:
17001</p>
17002
17003<blockquote><pre><ins>
17004template&lt;class R, class... Argtypes&gt;
17005void swap(packaged_task&lt;R(ArgTypes...)&gt;&amp; x, packaged_task&lt;R(ArgTypes...)&gt;&amp; y);
17006</ins></pre>
17007<blockquote>
17008<p><ins>
17009<i>Effects:</i> <tt>x.swap(y)</tt>
17010</ins></p>
17011<p><ins>
17012<i>Throws:</i> Nothing.
17013</ins></p>
17014</blockquote>
17015</blockquote>
17016</li>
17017</ol>
17018
17019
17020
17021
17022
17023<hr>
17024<h3><a name="1093"></a>1093. Multiple definitions for random_shuffle algorithm</h3>
17025<p><b>Section:</b> 25.3.12 [alg.random.shuffle] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
17026 <b>Submitter:</b> Alisdair Meredith <b>Opened:</b> 2009-03-22  <b>Last modified:</b> 2009-10-26</p>
17027<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#alg.random.shuffle">issues</a> in [alg.random.shuffle].</p>
17028<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
17029<p><b>Discussion:</b></p>
17030
17031<p>
17032There are a couple of issues with the declaration of the <tt>random_shuffle</tt>
17033algorithm accepting a random number engine.
17034</p>
17035
17036<ol type="i">
17037<li>
17038The Iterators must be shuffle iterators, yet this requirement is missing.
17039</li>
17040<li>
17041The <tt>RandomNumberEngine</tt> concept is now provided by the random number
17042library
17043(<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2836.pdf">n2836</a>)
17044and the placeholder should be removed.
17045</li>
17046</ol>
17047
17048<p><i>[
170492009-05-02 Daniel adds:
17050]</i></p>
17051
17052
17053<blockquote>
17054<p>
17055this issue completes adding necessary requirement to the
17056third new <tt>random_shuffle</tt> overload. The current suggestion is:
17057</p>
17058
17059<blockquote><pre>template&lt;RandomAccessIterator Iter, UniformRandomNumberGenerator Rand&gt;
17060requires ShuffleIterator&lt;Iter&gt;
17061void random_shuffle(Iter first, Iter last, Rand&amp;&amp; g);
17062</pre></blockquote>
17063
17064<p>
17065IMO this is still insufficient and I suggest to add the requirement
17066</p>
17067<blockquote><pre>Convertible&lt;Rand::result_type, Iter::difference_type&gt;
17068</pre></blockquote>
17069<p>
17070to the list (as the two other overloads already have).
17071</p>
17072
17073<p>
17074Rationale:
17075</p>
17076
17077<blockquote>
17078<p>
17079Its true that this third overload is somewhat different from the remaining
17080two. Nevertheless we know from <tt>UniformRandomNumberGenerator</tt>, that
17081it's <tt>result_type</tt> is an integral type and that it satisfies
17082<tt>UnsignedIntegralLike&lt;result_type&gt;</tt>.
17083</p>
17084<p>
17085To realize it's designated task, the algorithm has to invoke the
17086<tt>Callable</tt> aspect of <tt>g</tt> and needs to perform some algebra involving
17087it's <tt>min()/max()</tt> limits to compute another index value that
17088at this point is converted into <tt>Iter::difference_type</tt>. This is so,
17089because 24.2.5 [random.access.iterators] uses this type as argument
17090of it's algebraic operators. Alternatively consider the equivalent
17091iterator algorithms in 24.4.4 [iterator.operations] with the same result.
17092</p>
17093<p>
17094This argument leads us to the conclusion that we also need
17095<tt>Convertible&lt;Rand::result_type, Iter::difference_type&gt;</tt> here.
17096</p>
17097</blockquote>
17098
17099</blockquote>
17100
17101<p><i>[
17102Batavia (2009-05):
17103]</i></p>
17104
17105<blockquote>
17106<p>
17107Alisdair notes that point (ii) has already been addressed.
17108</p>
17109<p>
17110We agree with the proposed resolution to point (i)
17111with Daniel's added requirement.
17112</p>
17113<p>
17114Move to Review.
17115</p>
17116</blockquote>
17117
17118<p><i>[
171192009-06-05 Daniel updated proposed wording as recommended in Batavia.
17120]</i></p>
17121
17122
17123<p><i>[
171242009-07-28 Alisdair adds:
17125]</i></p>
17126
17127
17128<blockquote>
17129Revert to Open, with a note there is consensus on direction but the
17130wording needs updating to reflect removal of concepts.
17131</blockquote>
17132
17133<p><i>[
171342009-10 post-Santa Cruz:
17135]</i></p>
17136
17137
17138<blockquote>
17139Leave Open, Walter to work on it.
17140</blockquote>
17141
17142
17143
17144<p><b>Proposed resolution:</b></p>
17145<p>
17146Change in  [algorithms.syn] and 25.3.12 [alg.random.shuffle]:
17147</p>
17148
17149<blockquote><pre><del>concept UniformRandomNumberGenerator&lt;typename Rand&gt; { }</del>
17150template&lt;RandomAccessIterator Iter, UniformRandomNumberGenerator Rand&gt;
17151  <ins>requires ShuffleIterator&lt;Iter&gt; &amp;&amp;
17152  Convertible&lt;Rand::result_type, Iter::difference_type&gt;</ins>
17153  void random_shuffle(Iter first, Iter last, Rand&amp;&amp; g);
17154</pre></blockquote>
17155
17156
17157
17158
17159
17160
17161<hr>
17162<h3><a name="1094"></a>1094. Response to JP 65 and JP 66</h3>
17163<p><b>Section:</b> 27.5.4.3 [iostate.flags] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
17164 <b>Submitter:</b> P.J. Plauger <b>Opened:</b> 2009-03-24  <b>Last modified:</b> 2009-10-20</p>
17165<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#iostate.flags">issues</a> in [iostate.flags].</p>
17166<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
17167<p><b>Discussion:</b></p>
17168<p><b>Addresses JP 65 and JP 66</b></p>
17169
17170<p>
17171Switch from "unspecified-bool-type" to "explicit operator bool() const". 
17172</p>
17173
17174<p>
17175Replace <tt>operator unspecified-bool-type() const;</tt>" with <tt>explicit operator bool() const;</tt>
17176</p>
17177
17178<p><i>[
17179Batavia (2009-05):
17180]</i></p>
17181
17182<blockquote>
17183We agree with the proposed resolution.
17184Move to Review.
17185</blockquote>
17186
17187<p><i>[
171882009 Santa Cruz:
17189]</i></p>
17190
17191
17192<blockquote>
17193Moved to Ready.
17194</blockquote>
17195
17196
17197
17198<p><b>Proposed resolution:</b></p>
17199<p>
17200Change the synopis in 27.5.4 [ios]:
17201</p>
17202
17203<blockquote><pre><ins>explicit</ins> operator <del><i>unspecified-bool-type</i></del> <ins>bool</ins>() const;
17204</pre></blockquote>
17205
17206<p>
17207Change 27.5.4.3 [iostate.flags]:
17208</p>
17209
17210<blockquote><pre><ins>explicit</ins> operator <del><i>unspecified-bool-type</i></del> <ins>bool</ins>() const;
17211</pre>
17212
17213<blockquote>
17214<p>
17215-1- <i>Returns:</i> <ins><tt>!fail()</tt></ins> <del>If <tt>fail()</tt> then a value that will evaluate
17216false in a boolean context; otherwise a value that will evaluate true in
17217a boolean context. The value type returned shall not be convertible to
17218int.</del>
17219</p>
17220<p>
17221<del>[<i>Note:</i> This conversion can be used in contexts where a bool is expected
17222(e.g., an <tt>if</tt> condition); however, implicit conversions (e.g.,
17223to <tt>int</tt>) that can occur with <tt>bool</tt> are not allowed,
17224eliminating some sources of user error. One possible implementation
17225choice for this type is pointer-to-member. <i>-- end note</i>]</del>
17226</p>
17227</blockquote>
17228</blockquote>
17229
17230
17231
17232
17233
17234
17235
17236<hr>
17237<h3><a name="1095"></a>1095. <i>Shared objects and the library</i> wording unclear</h3>
17238<p><b>Section:</b> 17.6.3.10 [res.on.objects] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
17239 <b>Submitter:</b> Beman Dawes <b>Opened:</b> 2009-03-27  <b>Last modified:</b> 2009-10-21</p>
17240<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
17241<p><b>Discussion:</b></p>
17242<p>
17243<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2775.htm">N2775</a>,
17244<i>Small library thread-safety revisions</i>, among other changes, removed a note from
1724517.6.3.10 [res.on.objects] that read:
17246</p>
17247
17248<blockquote>
17249[<i>Note:</i> This prohibition against concurrent non-const access means that
17250modifying an object of a standard library type shared between threads
17251without using a locking mechanism may result in a data race. <i>--end note</i>.]
17252</blockquote>
17253
17254<p>
17255That resulted in wording which is technically correct but can only be
17256understood by reading the lengthy and complex 17.6.4.8 [res.on.data.races]
17257Data race avoidance. This has the effect of making
1725817.6.3.10 [res.on.objects] unclear, and has already resulted in a query
17259to the LWG reflector. See c++std-lib-23194.
17260</p>
17261
17262<p><i>[
17263Batavia (2009-05):
17264]</i></p>
17265
17266<blockquote>
17267<p>
17268The proposed wording seems to need a bit of tweaking
17269("really bad idea" isn't quite up to standardese).
17270We would like feedback
17271as to whether the original Note's removal was intentional.
17272</p>
17273<p>
17274Change the phrase "is a really bad idea"
17275to "risks undefined behavior" and
17276move to Review status.
17277</p>
17278</blockquote>
17279
17280<p><i>[
172812009-10 Santa Cruz:
17282]</i></p>
17283
17284
17285<blockquote>
17286Note: Change to read: "Modifying...", Delete 'thus', move to Ready
17287</blockquote>
17288
17289
17290
17291<p><b>Proposed resolution:</b></p>
17292<p>
17293Change 17.6.3.10 [res.on.objects] as indicated:
17294</p>
17295
17296<blockquote>
17297<p>
17298The behavior of a program is undefined if calls to standard library
17299functions from different threads may introduce a data race. The
17300conditions under which this may occur are specified in 17.6.4.7.
17301</p>
17302<p><ins>
17303[<i>Note:</i> Modifying an object of a standard library type shared between
17304threads risks undefined behavior unless objects of the type are explicitly
17305specified as being sharable without data races or the user supplies a
17306locking mechanism. <i>--end note</i>]
17307</ins></p>
17308</blockquote>
17309
17310
17311
17312
17313
17314<hr>
17315<h3><a name="1097"></a>1097. #define __STDCPP_THREADS</h3>
17316<p><b>Section:</b> 18.2 [support.types] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
17317 <b>Submitter:</b> Jens Maurer <b>Opened:</b> 2009-04-03  <b>Last modified:</b> 2009-10-21</p>
17318<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#support.types">issues</a> in [support.types].</p>
17319<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
17320<p><b>Discussion:</b></p>
17321<p><b>Addresses DE 18</b></p>
17322
17323<p>
17324Freestanding implementations do not (necessarily) have
17325  support for multiple threads (see 1.10 [intro.multithread]).
17326  Applications and libraries may want to optimize for the
17327  absence of threads.  I therefore propose a preprocessor
17328  macro to indicate whether multiple threads can occur.
17329</p>
17330
17331<p>
17332There is ample prior implementation experience for this
17333  feature with various spellings of the macro name.  For
17334  example, gcc implicitly defines <tt>_REENTRANT</tt>
17335  if multi-threading support is selected on the compiler
17336  command-line.
17337</p>
17338
17339<p>
17340While this is submitted as a library issue, it may be more
17341  appropriate to add the macro in 16.8 cpp.predefined in the
17342  core language.
17343</p>
17344
17345<p>
17346See also
17347<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2693.html">N2693</a>.
17348</p>
17349
17350<p><i>[
17351Batavia (2009-05):
17352]</i></p>
17353
17354<blockquote>
17355<p>
17356We agree with the issue, and believe it is properly a library issue.
17357</p>
17358<p>
17359We prefer that the macro be conditionally defined
17360as part of the <tt>&lt;thread&gt;</tt> header.
17361</p>
17362<p>
17363Move to Review.
17364</p>
17365</blockquote>
17366
17367<p><i>[
173682009-10 Santa Cruz:
17369]</i></p>
17370
17371
17372<blockquote>
17373Move to Ready.
17374</blockquote>
17375
17376
17377
17378<p><b>Proposed resolution:</b></p>
17379<p>
17380Insert a new subsection before 18.2 [support.types], entitled
17381"Feature Macros" (support.macros):
17382</p>
17383<blockquote>
17384<p>
17385The standard library defines the following macros; no explicit
17386prior inclusion of any header file is necessary.
17387</p>
17388<blockquote>
17389<dl>
17390<dt><tt>__STDCPP_THREADS</tt></dt>
17391<dd>
17392The macro <tt>__STDCPP_THREADS</tt> shall be defined if and only if a
17393    program can have more than one thread of execution (1.10 [intro.multithread]).
17394If the macro is defined, it shall have the same
17395    value as the predefined macro <tt>__cplusplus</tt> (16.8 [cpp.predefined]).
17396</dd>
17397</dl>
17398</blockquote>
17399</blockquote>
17400
17401
17402
17403
17404
17405
17406<hr>
17407<h3><a name="1098"></a>1098. definition of get_pointer_safety()</h3>
17408<p><b>Section:</b> 20.8.15.6 [util.dynamic.safety] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
17409 <b>Submitter:</b> Jens Maurer <b>Opened:</b> 2009-04-03  <b>Last modified:</b> 2009-10-23</p>
17410<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#util.dynamic.safety">issues</a> in [util.dynamic.safety].</p>
17411<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
17412<p><b>Discussion:</b></p>
17413<p><b>Addresses DE 18</b></p>
17414
17415<p>
17416 In 20.8.15.6 [util.dynamic.safety], <tt>get_pointer_safety()</tt> purports
17417to define behavior for
17418 non-safely derived pointers (3.7.4.3 [basic.stc.dynamic.safety]).  However,
17419 the cited core-language section in paragraph 4 specifies undefined behavior
17420 for the use of such pointer values.  This seems an unfortunate near-contradiction.
17421 I suggest to specify the term <i>relaxed pointer safety</i> in
17422 the core language section and refer to it from the library description.
17423 This issue deals with the library part, the corresponding core issue (c++std-core-13940)
17424 deals with the core modifications.
17425</p>
17426
17427<p>
17428See also
17429<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2693.html">N2693</a>.
17430</p>
17431
17432<p><i>[
17433Batavia (2009-05):
17434]</i></p>
17435
17436<blockquote>
17437<p>
17438We recommend if this issue is to be moved,
17439the issue be moved concurrently with the cited Core issue.
17440</p>
17441<p>
17442We agree with the intent of the proposed resolution.
17443We would like input from garbage collection specialists.
17444</p>
17445<p>
17446Move to Open.
17447</p>
17448</blockquote>
17449
17450<p><i>[
174512009-10 Santa Cruz:
17452]</i></p>
17453
17454
17455<blockquote>
17456The core issue is 853 and is in Ready status.
17457</blockquote>
17458
17459
17460
17461<p><b>Proposed resolution:</b></p>
17462<p>
17463In 20.8.15.6 [util.dynamic.safety] p16, replace the description of
17464<tt>get_pointer_safety()</tt> with:
17465</p>
17466
17467<blockquote>
17468<p>
17469<tt>pointer_safety get_pointer_safety();</tt>
17470</p>
17471<blockquote>
17472<p>
17473<del><i>Returns:</i> an enumeration value indicating the implementation's treatment
17474of pointers that are not safely derived (3.7.4.3). Returns
17475<tt>pointer_safety::relaxed</tt> if pointers that are not safely derived will be
17476treated the same as pointers that are safely derived for the duration of
17477the program. Returns <tt>pointer_safety::preferred</tt> if pointers that are not
17478safely derived will be treated the same as pointers that are safely
17479derived for the duration of the program but allows the implementation to
17480hint that it could be desirable to avoid dereferencing pointers that are
17481not safely derived as described. [<i>Example:</i> <tt>pointer_safety::preferred</tt>
17482might be returned to detect if a leak detector is running to avoid
17483spurious leak reports. -- <i>end note</i>] Returns <tt>pointer_safety::strict</tt> if
17484pointers that are not safely derived might be treated differently than
17485pointers that are safely derived.</del>
17486</p>
17487<p><ins>
17488<i>Returns:</i> Returns <tt>pointer_safety::strict</tt> if the implementation has
17489   strict pointer safety (3.7.4.3 [basic.stc.dynamic.safety]). It is
17490   implementation-defined whether <tt>get_pointer_safety</tt> returns
17491   <tt>pointer_safety::relaxed</tt> or <tt>pointer_safety::preferred</tt> if the
17492   implementation has relaxed pointer safety
17493   (3.7.4.3 [basic.stc.dynamic.safety]).<sup>Footnote</sup>
17494</ins></p>
17495
17496<p><ins>
17497<i>Throws:</i> nothing
17498</ins></p>
17499
17500<p><ins>
17501Footnote) <tt>pointer_safety::preferred</tt> might be returned to indicate to the
17502   program that a leak detector is running so that the program can avoid
17503   spurious leak reports.
17504</ins>
17505</p>
17506
17507</blockquote>
17508</blockquote>
17509
17510
17511
17512
17513
17514<hr>
17515<h3><a name="1099"></a>1099. Various issues</h3>
17516<p><b>Section:</b> 17 [library] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#NAD">Tentatively NAD</a>
17517 <b>Submitter:</b> David Abrahams <b>Opened:</b> 2009-03-21  <b>Last modified:</b> 2009-10-26</p>
17518<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#library">active issues</a> in [library].</p>
17519<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#library">issues</a> in [library].</p>
17520<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Tentatively%20NAD">Tentatively NAD</a> status.</p>
17521<p><b>Discussion:</b></p>
17522<p>
17523Notes
17524</p>
17525<blockquote>
17526<p>
17527[2009-03-21 Sat] p. 535 at the top we need MoveConstructible V1,
17528MoveConstructible V2 (where V1,V2 are defined on 539).  Also make_tuple
17529on 550
17530</p>
17531
17532<blockquote>
17533<p>
17534CD-1 reads:
17535</p>
17536
17537<blockquote><pre>template &lt;MoveConstructible T1, MoveConstructible T2&gt; 
17538pair&lt;V1, V2&gt; make_pair(T1&amp;&amp;, T2&amp;&amp;); 
17539</pre></blockquote>
17540
17541<p>
17542Actually I'm guessing we need something like <tt>MoveConstructible&lt;V1,T1&gt;</tt>,
17543i.e. "<tt>V1</tt> can be constructed from an rvalue of type <tt>T1</tt>."
17544</p>
17545
17546<p>
17547Ditto for <tt>make_tuple</tt>
17548</p>
17549</blockquote>
17550
17551<p>
17552[2009-03-21 Sat] p1183 thread ctor, and in general, we need a way to
17553talk about "copiable from generalized rvalue ref argument" for cases
17554where we're going to forward and copy.  
17555</p>
17556<blockquote>
17557<p>
17558   This issue may well be quite large.  Language in para 4 about "if
17559   an lvalue" is wrong because types aren't expressions.
17560</p>
17561
17562<blockquote>
17563<p>
17564Maybe we should define the term "move" so we can just say in the
17565effects, "<tt>f</tt> is moved into the newly-created thread" or something, and
17566agree (and ideally document) that saying "<tt>f</tt> is moved" implies 
17567</p>
17568
17569<blockquote><pre>F x(move(f))
17570</pre></blockquote>
17571
17572<p>
17573is required to work.  That would cover both ctors at once.
17574</p>
17575</blockquote>
17576
17577<p>
17578   p1199, call_once has all the same issues.
17579</p>
17580</blockquote>
17581<p>
17582[2009-03-21 Sat] p869 InputIterator pointer type should not be required
17583to be convertible to const value_type*, rather it needs to have a
17584operator-&gt; of its own that can be used for the value type.
17585</p>
17586
17587<blockquote>
17588This one is serious and unrelated to the move issue.
17589</blockquote>
17590
17591<p>
17592[2009-03-21 Sat] p818 stack has the same problem with default ctor.
17593</p>
17594<p>
17595[2009-03-21 Sat] p816 priority_queue has the same sorts of problems as queue, only more so
17596</p>
17597<blockquote><pre>   requires MoveConstructible&lt;Cont&gt; 
17598     explicit priority_queue(const Compare&amp; x = Compare(), Cont&amp;&amp; = Cont()); 
17599</pre>
17600<p>
17601   Don't require MoveConstructible when default constructing Cont.
17602   Also missing semantics for move ctor.
17603</p>
17604</blockquote>
17605<p>
17606 [2009-03-21 Sat] Why are Allocators required to be CopyConstructible as
17607 opposed to MoveConstructible?
17608</p>
17609<p>
17610 [2009-03-21 Sat] p813 queue needs a separate default ctor (Cont needn't
17611 be MoveConstructible).  No documented semantics for move c'tor.  Or
17612 *any* of its 7 ctors!
17613</p>
17614<p>
17615 [2009-03-21 Sat] std::array should have constructors for C++0x,
17616 consequently must consider move construction.
17617</p>
17618
17619<p><i>[
176202009-05-01 Daniel adds:
17621]</i></p>
17622
17623
17624<blockquote>
17625This could be done as part of <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1035">1035</a>, which already handles
17626deviation of <tt>std::array</tt> from container tables.
17627</blockquote>
17628
17629<p>
17630 [2009-03-21 Sat] p622 all messed up.
17631</p>
17632<blockquote>
17633<p>
17634   para 8 "implementation-defined" is the wrong term; should be "see
17635   below" or something.  
17636</p>
17637<p>
17638   para 12 "will be selected" doesn't make any sense because we're not
17639   talking about actual arg types.
17640</p>
17641<p>
17642   paras 9-13 need to be totally rewritten for concepts.
17643</p>
17644</blockquote>
17645
17646<p>
17647 [2009-03-21 Sat] Null pointer comparisons (p587) have all become
17648 unconstrained.  Need to fix that
17649</p>
17650<p>
17651 [2009-03-21 Sat] mem_fun_t etc. definition doesn't match declaration.
17652  We think CopyConstructible is the right reqt.
17653</p>
17654<p>
17655 make_pair needs Constructible&lt;V1, T1&amp;&amp;&gt; requirements!
17656</p>
17657<p>
17658 make_tuple needs something similar
17659</p>
17660<p>
17661 tuple bug in synopsis:
17662</p>
17663<blockquote><pre>   template &lt;class... UTypes&gt;
17664   requires Constructible&lt;Types, const UTypes&amp;&gt;...
17665   template &lt;class... UTypes&gt;
17666   requires Constructible&lt;Types, RvalueOf&lt;UTypes&gt;::type&gt;...
17667</pre>
17668<p>
17669   Note: removal of MoveConstructible requirements in std::function makes
17670   these routines unconstrained!
17671</p>
17672</blockquote>
17673
17674<p><i>[
176752009-05-02 Daniel adds:
17676]</i></p>
17677
17678
17679<blockquote>
17680This part of the issue is already covered by <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1077">1077</a>.
17681</blockquote>
17682
17683<p>
17684 these unique_ptr constructors are broken [ I think this is covered in "p622 all messed up" ]
17685</p>
17686<blockquote><pre> unique_ptr(pointer p, implementation-defined d);
17687 unique_ptr(pointer p, implementation-defined d);
17688</pre></blockquote>
17689<p>
17690 multimap range constructor should not have MoveConstructible&lt;value_type&gt; requirement.
17691</p>
17692<blockquote>
17693   same with insert(..., P&amp;&amp;); multiset has the same issue, as do
17694   unordered_multiset and unordered_multimap. Review these!
17695</blockquote>
17696
17697</blockquote>
17698
17699<p><i>[
17700Batavia (2009-05):
17701]</i></p>
17702
17703<blockquote>
17704Move to Open, pending proposed wording from Dave for further review.
17705</blockquote>
17706
17707<p><i>[
177082009-10 post-Santa Cruz:
17709]</i></p>
17710
17711
17712<blockquote>
17713Tentatively NAD.  We are not sure what has been addressed and what hasn't.
17714Recommend closing unless someone sorts this out into something more readable.
17715</blockquote>
17716
17717
17718
17719<p><b>Proposed resolution:</b></p>
17720<p>
17721</p>
17722
17723
17724
17725
17726
17727<hr>
17728<h3><a name="1100"></a>1100. <tt>auto_ptr</tt> to <tt>unique_ptr</tt> conversion</h3>
17729<p><b>Section:</b> 20.8.14.2.1 [unique.ptr.single.ctor] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
17730 <b>Submitter:</b> Howard Hinnant <b>Opened:</b> 2009-04-25  <b>Last modified:</b> 2009-10-21</p>
17731<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#unique.ptr.single.ctor">active issues</a> in [unique.ptr.single.ctor].</p>
17732<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#unique.ptr.single.ctor">issues</a> in [unique.ptr.single.ctor].</p>
17733<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
17734<p><b>Discussion:</b></p>
17735<p>
17736Message c++std-lib-23182 led to a discussion in which several people
17737expressed interest in being able to convert an <tt>auto_ptr</tt> to a
17738<tt>unique_ptr</tt> without the need to call <tt>release</tt>.  Below is
17739wording to accomplish this.
17740</p>
17741
17742<p><i>[
17743Batavia (2009-05):
17744]</i></p>
17745
17746<blockquote>
17747<p>
17748Pete believes it not a good idea to separate parts of a class's definition.
17749Therefore, if we do this,
17750it should be part of <tt>unique-ptr</tt>'s specification.
17751</p>
17752<p>
17753Alisdair believes the lvalue overload may be not necessary.
17754</p>
17755<p>
17756Marc believes it is more than just sugar,
17757as it does ease the transition to <tt>unique-ptr</tt>.
17758</p>
17759<p>
17760We agree with the resolution as presented.
17761Move to Tentatively Ready.
17762</p>
17763</blockquote>
17764
17765<p><i>[
177662009-07 Frankfurt
17767]</i></p>
17768
17769
17770<blockquote>
17771Moved from Tentatively Ready to Open only because the wording needs to be
17772tweaked for concepts removal.
17773</blockquote>
17774
17775<p><i>[
177762009-08-01 Howard deconceptifies wording:
17777]</i></p>
17778
17779
17780<blockquote>
17781I also moved the change from D.10 [depr.auto.ptr]
17782to 20.8.14.2 [unique.ptr.single] per the Editor's request
17783in Batavia (as long as I was making changes anyway).  Set back
17784to Review.
17785</blockquote>
17786
17787<p><i>[
177882009-10 Santa Cruz:
17789]</i></p>
17790
17791
17792<blockquote>
17793Move to Ready.
17794</blockquote>
17795
17796
17797
17798<p><b>Proposed resolution:</b></p>
17799<p>
17800Add to 20.8.14.2 [unique.ptr.single]:
17801</p>
17802
17803<blockquote><pre>template &lt;class T, class D&gt;
17804class unique_ptr
17805{
17806public:
17807<ins>    template &lt;class U&gt;
17808      unique_ptr(auto_ptr&lt;U&gt;&amp; u);
17809    template &lt;class U&gt;
17810      unique_ptr(auto_ptr&lt;U&gt;&amp;&amp; u);</ins>
17811};
17812</pre></blockquote>
17813
17814<p>
17815Add to 20.8.14.2.1 [unique.ptr.single.ctor]:
17816</p>
17817
17818<blockquote><pre>template &lt;class U&gt;
17819  unique_ptr(auto_ptr&lt;U&gt;&amp; u);
17820template &lt;class U&gt;
17821  unique_ptr(auto_ptr&lt;U&gt;&amp;&amp; u);
17822</pre>
17823<blockquote>
17824<p>
17825<i>Effects:</i> Constructs a <tt>unique_ptr</tt> with <tt>u.release()</tt>.
17826</p>
17827
17828<p>
17829<i>Postconditions:</i> <tt>get() == </tt> the value <tt>u.get()</tt> had before
17830the construciton, modulo any required offset adjustments resulting from the cast from
17831<tt>U*</tt> to <tt>T*</tt>.  <tt>u.get() == nullptr</tt>.
17832</p>
17833
17834<p>
17835<i>Throws:</i> nothing.
17836</p>
17837
17838<p>
17839<i>Remarks:</i> <tt>U*</tt> shall be implicitly convertible to <tt>T*</tt> and
17840<tt>D</tt> shall be the same type as <tt>default_delete&lt;T&gt;</tt>, else these
17841constructors shall not participate in overload resolution.
17842</p>
17843</blockquote>
17844</blockquote>
17845
17846
17847
17848
17849
17850
17851<hr>
17852<h3><a name="1104"></a>1104. <tt>basic_ios::move</tt> should accept lvalues</h3>
17853<p><b>Section:</b> 27.5.4.2 [basic.ios.members] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
17854 <b>Submitter:</b> Howard Hinnant <b>Opened:</b> 2009-04-25  <b>Last modified:</b> 2009-10-20</p>
17855<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#basic.ios.members">active issues</a> in [basic.ios.members].</p>
17856<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#basic.ios.members">issues</a> in [basic.ios.members].</p>
17857<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
17858<p><b>Discussion:</b></p>
17859<p>
17860With the rvalue reference changes in
17861<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2844.html">N2844</a>
17862<tt>basic_ios::move</tt> no longer has the most convenient signature:
17863</p>
17864
17865<blockquote><pre>void move(basic_ios&amp;&amp; rhs);
17866</pre></blockquote>
17867
17868<p>
17869This signature should be changed to accept lvalues.  It does not need to be
17870overloaded to accept rvalues.  This is a special case that only derived clients
17871will see.  The generic <tt>move</tt> still needs to accept rvalues.
17872</p>
17873
17874<p><i>[
17875Batavia (2009-05):
17876]</i></p>
17877
17878<blockquote>
17879<p>
17880Tom prefers, on general principles, to provide both overloads.
17881Alisdair agrees.
17882</p>
17883<p>
17884Howard points out that there is no backward compatibility issue
17885as this is new to C++0X.
17886</p>
17887<p>
17888We agree that both overloads should be provided,
17889and Howard will provide the additional wording.
17890Move to Open.
17891</p>
17892</blockquote>
17893
17894<p><i>[
178952009-05-23 Howard adds:
17896]</i></p>
17897
17898
17899<blockquote>
17900Added overload, moved to Review.
17901</blockquote>
17902
17903<p><i>[
179042009 Santa Cruz:
17905]</i></p>
17906
17907
17908<blockquote>
17909Move to Ready.
17910</blockquote>
17911
17912
17913
17914<p><b>Proposed resolution:</b></p>
17915<p>
17916Add a signature to the existing prototype in the synopsis of 27.5.4 [ios]
17917and in 27.5.4.2 [basic.ios.members]:
17918</p>
17919
17920<blockquote><pre><ins>void move(basic_ios&amp; rhs);</ins>
17921void move(basic_ios&amp;&amp; rhs);
17922</pre></blockquote>
17923
17924
17925
17926
17927
17928<hr>
17929<h3><a name="1106"></a>1106. Multiple exceptions from connected <tt>shared_future::get()</tt>?</h3>
17930<p><b>Section:</b> 30.6.7 [future.shared_future] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
17931 <b>Submitter:</b> Thomas J. Gritzan <b>Opened:</b> 2009-04-03  <b>Last modified:</b> 2009-05-23</p>
17932<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#future.shared_future">issues</a> in [future.shared_future].</p>
17933<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
17934<p><b>Discussion:</b></p>
17935<p>
17936It is not clear, if multiple threads are waiting in a 
17937<tt>shared_future::get()</tt> call, if each will rethrow the stored exception.
17938</p>
17939<p>
17940Paragraph 9 reads: 
17941</p>
17942<blockquote>
17943<i>Throws:</i> the stored exception, if an exception was stored and not 
17944retrieved before.
17945</blockquote>
17946<p>
17947The "not retrieved before" suggests that only one exception is thrown, 
17948but one exception for each call to <tt>get()</tt> is needed, and multiple calls 
17949to <tt>get()</tt> even on the same <tt>shared_future</tt> object seem to be allowed. 
17950</p>
17951<p>
17952I suggest removing "and not retrieved before" from the Throws paragraph. 
17953I recommend adding a note that explains that multiple calls on <tt>get()</tt> are 
17954allowed, and each call would result in an exception if an exception was 
17955stored. 
17956</p>
17957
17958<p><i>[
17959Batavia (2009-05):
17960]</i></p>
17961
17962<blockquote>
17963<p>
17964We note there is a pending paper by Detlef
17965on such <tt>future</tt>-related issues;
17966we would like to wait for his paper before proceeding.
17967</p>
17968<p>
17969Alisdair suggests we may want language to clarify that this
17970<tt>get()</tt> function can be called from several threads
17971with no need for explicit locking.
17972</p>
17973<p>
17974Move to Open.
17975</p>
17976</blockquote>
17977
17978
17979<p><b>Proposed resolution:</b></p>
17980<p>
17981Change 30.6.7 [future.shared_future]:
17982</p>
17983
17984<blockquote><pre>const R&amp; shared_future::get() const; 
17985R&amp; shared_future&lt;R&amp;&gt;::get() const; 
17986void shared_future&lt;void&gt;::get() const;
17987</pre>
17988<blockquote>
17989<p>...</p>
17990<p>
17991-9- <i>Throws:</i> the stored exception, if an exception was stored<del> and not retrieved before</del>.
17992<ins>
17993[<i>Note:</i> Multiple calls on <tt>get()</tt> are 
17994allowed, and each call would result in an exception if an exception was 
17995stored. &#8212; <i>end note</i>]
17996</ins>
17997</p>
17998</blockquote>
17999</blockquote>
18000
18001
18002
18003
18004
18005
18006<hr>
18007<h3><a name="1108"></a>1108. thread.req.exception overly constrains implementations</h3>
18008<p><b>Section:</b> 30.2.2 [thread.req.exception] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Tentatively Ready</a>
18009 <b>Submitter:</b> Christopher Kohlhoff <b>Opened:</b> 2009-04-25  <b>Last modified:</b> 2009-10-26</p>
18010<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Tentatively%20Ready">Tentatively Ready</a> status.</p>
18011<p><b>Discussion:</b></p>
18012<p>
18013The current formulation of 30.2.2 [thread.req.exception]/2 reads:
18014</p>
18015<blockquote>
18016The error_category of the <tt>error_code</tt> reported by such an
18017exception's <tt>code()</tt> member function is as specified in the error
18018condition Clause.
18019</blockquote>
18020<p>
18021This constraint on the code's associated <tt>error_categor</tt> means an
18022implementation must perform a mapping from the system-generated
18023error to a <tt>generic_category()</tt> error code. The problems with this
18024include:
18025</p>
18026
18027<ul>
18028<li>
18029The mapping is always performed, even if the resultant value is
18030 never used.
18031</li>
18032<li>
18033<p>
18034The original error produced by the operating system is lost.
18035</p>
18036</li>
18037</ul>
18038<p>
18039The latter was one of Peter Dimov's main objections (in a private
18040email discussion) to the original <tt>error_code</tt>-only design, and led to
18041the creation of <tt>error_condition</tt> in the first place. Specifically,
18042<tt>error_code</tt> and <tt>error_condition</tt> are intended to perform the following
18043roles:
18044</p>
18045<ul>
18046<li>
18047<tt>error_code</tt> holds the original error produced by the operating
18048 system.
18049</li>
18050<li>
18051<tt>error_condition</tt> and the generic category provide a set of well
18052 known error constants that error codes may be tested against.
18053</li>
18054</ul>
18055<p>
18056Any mapping determining correspondence of the returned error code to
18057the conditions listed in the error condition clause falls under the
18058"latitude" granted to implementors in 19.5.1.5 [syserr.errcat.objects].
18059(Although obviously their latitude is restricted a little by the
18060need to match the right error condition when returning an error code
18061from a library function.)
18062</p>
18063<p>
18064It is important that this <tt>error_code/error_condition</tt> usage is done
18065correctly for the thread library since it is likely to set the
18066pattern for future TR libraries that interact with the operating
18067system.
18068</p>
18069
18070<p><i>[
18071Batavia (2009-05):
18072]</i></p>
18073
18074<blockquote>
18075Move to Open, and recommend the issue be deferred until after the next
18076Committee Draft is issued.
18077</blockquote>
18078
18079<p><i>[
180802009-10 post-Santa Cruz:
18081]</i></p>
18082
18083
18084<blockquote>
18085Move to Tentatively Ready.
18086</blockquote>
18087
18088
18089
18090<p><b>Proposed resolution:</b></p>
18091<p>
18092Change 30.2.2 [thread.req.exception]/2:
18093</p>
18094
18095<blockquote>
18096<p>
18097-2- <del>The <tt>error_category</tt> (19.5.1.1) of the <tt>error_code</tt> reported by
18098such an exception's <tt>code()</tt> member function 
18099is as specified in the error condition Clause.</del>
18100<ins>
18101The <tt>error_code</tt> reported by such an exception's <tt>code()</tt> member
18102function shall compare equal to one of the conditions specified in
18103the function's error condition Clause. [<i>Example:</i> When the thread
18104constructor fails:
18105</ins>
18106</p>
18107<blockquote><pre><ins>
18108ec.category() == implementation-defined // probably system_category
18109ec == errc::resource_unavailable_try_again // holds true
18110</ins></pre></blockquote>
18111
18112<p><ins>
18113&#8212; <i>end example</i>]
18114</ins></p>
18115
18116</blockquote>
18117
18118
18119
18120
18121
18122
18123<hr>
18124<h3><a name="1110"></a>1110. Is <tt>for_each</tt> overconstrained?</h3>
18125<p><b>Section:</b> 25.2.4 [alg.foreach] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
18126 <b>Submitter:</b> Alisdair Meredith <b>Opened:</b> 2009-04-29  <b>Last modified:</b> 2009-10-27</p>
18127<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#alg.foreach">issues</a> in [alg.foreach].</p>
18128<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
18129<p><b>Discussion:</b></p>
18130<p>
18131Quoting working paper for reference (25.2.4 [alg.foreach]):
18132</p>
18133
18134<blockquote>
18135<pre>template&lt;InputIterator Iter, Callable&lt;auto, Iter::reference&gt; Function&gt;
18136  requires CopyConstructible&lt;Function&gt;
18137  Function for_each(Iter first, Iter last, Function f);
18138</pre>
18139<blockquote>
18140<p>
181411 Effects: Applies f to the result of dereferencing every iterator in the
18142 range [first,last), starting from first and proceeding to last - 1.
18143</p>
18144<p>
181452 Returns: f.
18146</p>
18147<p>
181483 Complexity: Applies f exactly last - first times.
18149</p>
18150</blockquote>
18151</blockquote>
18152
18153<p>
18154P2 implies the passed object <tt>f</tt> should be invoked at each stage, rather than
18155some copy of <tt>f</tt>.  This is important if the return value is to usefully
18156accumulate changes.  So the requirements are an object of type <tt>Function</tt> can
18157be passed-by-value, invoked multiple times, and then return by value.  In
18158this case, <tt>MoveConstructible</tt> is sufficient. This would open support for
18159move-only functors, which might become important in concurrent code as you
18160can assume there are no other references (copies) of a move-only type and so
18161freely use them concurrently without additional locks.
18162</p>
18163
18164<p><i>[
18165See further discussion starting with c++std-lib-23686.
18166]</i></p>
18167
18168
18169<p><i>[
18170Batavia (2009-05):
18171]</i></p>
18172
18173<blockquote>
18174<p>
18175Pete suggests we may want to look at this in a broader context
18176involving other algorithms.
18177We should also consider the implications of parallelism.
18178</p>
18179<p>
18180Move to Open, and recommend the issue be deferred until after the next
18181Committee Draft is issued.
18182</p>
18183</blockquote>
18184
18185<p><i>[
181862009-10-14 Daniel de-conceptified the proposed resolution.
18187]</i></p>
18188
18189
18190<blockquote>
18191<p>
18192The note in 25.1 [algorithms.general]/9 already says the right thing:
18193</p>
18194<blockquote>
18195Unless otherwise specified, algorithms that take function objects
18196as arguments are permitted to copy those function objects freely.
18197</blockquote>
18198<p>
18199So we only need to ensure that the wording for <tt>for_each</tt> is sufficiently
18200clear, which is the intend of the following rewording.
18201</p>
18202</blockquote>
18203
18204<p><i>[
182052009-10-15 Daniel proposes:
18206]</i></p>
18207
18208
18209<blockquote>
18210<ul>
18211<li>
18212<p>
18213Add a new Requires clause just after the prototype declaration (25.2.4 [alg.foreach]):
18214</p>
18215<blockquote>
18216<p>
18217<ins><i>Requires:</i> <tt>Function</tt> shall be <tt>MoveConstructible</tt>
18218( [moveconstructible]), <tt>CopyConstructible</tt> is not required.</ins>
18219</p>
18220</blockquote>
18221</li>
18222<li>
18223<p>
18224Change 25.2.4 [alg.foreach]/2 as indicated:
18225</p>
18226
18227<blockquote>
18228<i>Returns:</i> <ins>std::move(</ins>f<ins>)</ins>.
18229</blockquote>
18230</li>
18231</ul>
18232</blockquote>
18233
18234<p><i>[
182352009-10 post-Santa Cruz:
18236]</i></p>
18237
18238
18239<blockquote>
18240Move to Tentatively Ready, using Daniel's wording without the portion
18241saying "CopyConstructible is not required".
18242</blockquote>
18243
18244<p><i>[
182452009-10-27 Daniel adds:
18246]</i></p>
18247
18248
18249<blockquote>
18250<p>
18251I see that during the Santa Cruz meeting the originally proposed addition
18252</p>
18253
18254<blockquote>
18255, <tt>CopyConstructible</tt> is not required.
18256</blockquote>
18257
18258<p>
18259was removed. I don't think that this removal was a good idea. The combination
18260of 25.1 [algorithms.general]/9
18261</p>
18262
18263<blockquote>
18264[<i>Note:</i> Unless otherwise specified, algorithms that take function objects
18265as arguments are permitted to copy those function objects freely.[..]
18266</blockquote>
18267
18268<p>
18269with the fact that <tt>CopyConstructible</tt> is a refinement <tt>MoveConstructible</tt>
18270makes it necessary that such an explicit statement is given. Even the
18271existence of the usage of <tt>std::move</tt> in the <i>Returns</i> clause doesn't
18272help much, because this would still be well-formed for a <tt>CopyConstructible</tt>
18273without move constructor. Let me add that the originally proposed
18274addition reflects current practice in the standard, e.g. 25.3.9 [alg.unique]/5
18275usages a similar terminology.
18276</p>
18277
18278<p>
18279For similar wording need in case for auto_ptr see <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#973">973</a>.
18280</p>
18281
18282<p><i>[
18283Howard: Moved from Tentatively Ready to Open.
18284]</i></p>
18285
18286</blockquote>
18287
18288
18289
18290<p><b>Proposed resolution:</b></p>
18291<ul>
18292<li>
18293<p>
18294Add a new Requires clause just after the prototype declaration (25.2.4 [alg.foreach]):
18295</p>
18296<blockquote>
18297<p>
18298<ins><i>Requires:</i> <tt>Function</tt> shall be <tt>MoveConstructible</tt>
18299( [moveconstructible]).</ins>
18300</p>
18301</blockquote>
18302</li>
18303<li>
18304<p>
18305Change 25.2.4 [alg.foreach]/2 as indicated:
18306</p>
18307
18308<blockquote>
18309<i>Returns:</i> <ins>std::move(</ins>f<ins>)</ins>.
18310</blockquote>
18311</li>
18312</ul>
18313
18314
18315
18316
18317
18318
18319
18320
18321<hr>
18322<h3><a name="1112"></a>1112. bitsets and new style for loop</h3>
18323<p><b>Section:</b> 20.3.7 [template.bitset] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#NAD%20Future">Tentatively NAD Future</a>
18324 <b>Submitter:</b> Alisdair Meredith <b>Opened:</b> 2009-05-06  <b>Last modified:</b> 2009-10-26</p>
18325<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#template.bitset">active issues</a> in [template.bitset].</p>
18326<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#template.bitset">issues</a> in [template.bitset].</p>
18327<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Tentatively%20NAD%20Future">Tentatively NAD Future</a> status.</p>
18328<p><b>Discussion:</b></p>
18329<p>
18330<tt>Std::bitset</tt> is a homogeneous container-like sequence of bits, yet it does
18331not model the Range concept so cannot be used with the new for-loop syntax.
18332It is the only such type in the library that does NOT support the new for
18333loop.
18334</p>
18335<p>
18336The obvious reason is that bitset does not support iterators.
18337</p>
18338<p>
18339At least two reasonable solutions are available:
18340</p>
18341<ol type="i">
18342<li>
18343Add an iterator interface to <tt>bitset</tt>, bringing its interface close to that
18344of <tt>std::array</tt>
18345</li>
18346<li>
18347Provide an unspecified concept_map for <tt>Range&lt;bitset&gt;</tt>.
18348</li>
18349</ol>
18350<p>
18351The latter will still need some kind of iterator-like adapter for <tt>bitset</tt>,
18352but gives implementers greater freedom on the details. E.g. begin/end return
18353some type that simply invokes <tt>operator[]</tt> on the object it wraps, and
18354increments its index on <tt>operator++</tt>.  A vendor can settle for <tt>InputIterator</tt>
18355support, rather than wrapping up a full <tt>RandomAccessIterator</tt>.
18356</p>
18357<p>
18358I have a mild preference for option (ii) as I think it is less work to
18359specify at this stage of the process, although (i) is probably more useful
18360in the long run.
18361</p>
18362<p>
18363Hmm, my wording looks a little woolly, as it does not say what the element
18364type of the range is.  Do I get a range of <tt>bool</tt>, <tt>bitset&lt;N&gt;::reference</tt>, or
18365something else entirely?
18366</p>
18367<p>
18368I guess most users will assume the behaviour of reference, but expect to
18369work with <tt>bool</tt>.  <tt>Bool</tt> is OK for read-only traversal, but you really need to
18370take a reference to a <tt>bitset::reference</tt> if you want to write back.
18371</p>
18372
18373<p><i>[
18374Batavia (2009-05):
18375]</i></p>
18376
18377<blockquote>
18378Move to Open.
18379We further recommend this be deferred until after the next Committee Draft.
18380</blockquote>
18381
18382<p><i>[
183832009-05-25 Alisdair adds:
18384]</i></p>
18385
18386
18387<blockquote>
18388<p>
18389I just stumbled over the <tt>Range concept_map</tt> for <tt>valarray</tt> and this should
18390probably set the precedent on how to write the wording.
18391</p>
18392
18393<p><i>[
18394Howard: I've replaced the proposed wording with Alisdair's suggestion.
18395]</i></p>
18396
18397
18398</blockquote>
18399
18400<p><i>[
184012009-07-24 Daniel modifies the proposed wording for non-concepts.
18402]</i></p>
18403
18404
18405<p><i>[
184062009-10 post-Santa Cruz:
18407]</i></p>
18408
18409
18410<blockquote>
18411Mark as Tentatively NAD Future due to the loss of concepts.
18412</blockquote>
18413
18414
18415
18416<p><b>Proposed resolution:</b></p>
18417<ol>
18418<li>
18419<p>
18420Modify the section 20.3.7 [template.bitset] <tt>&lt;bitset&gt;</tt> synopsis by adding
18421the following at the end of the synopsis:
18422</p>
18423<blockquote><pre><ins>
18424// XX.X.X bitset range access [bitset.range]
18425template&lt;size_t N&gt; <i>unspecified-1</i> begin(bitset&lt;N&gt;&amp;);
18426template&lt;size_t N&gt; <i>unspecified-2</i> begin(const bitset&lt;N&gt;&amp;);
18427template&lt;size_t N&gt; <i>unspecified-1</i> end(bitset&lt;N&gt;&amp;);
18428template&lt;size_t N&gt; <i>unspecified-2</i> end(const bitset&lt;N&gt;&amp;);
18429</ins>
18430</pre></blockquote>
18431</li>
18432<li>
18433<p>
18434Add a new section <ins>"bitset range access" [bitset.range]</ins>
18435after the current section 20.3.7.3 [bitset.operators] with the following series of
18436paragraphs:
18437</p>
18438<blockquote>
18439<p>
18440<ins>
184411.  In the <tt>begin</tt> and <tt>end</tt> function templates that follow, <i>unspecified-1</i>
18442is a type that meets the requirements of a mutable random access
18443iterator (24.2.5 [random.access.iterators]) whose <tt>value_type</tt> is <tt>bool</tt> and
18444whose reference type is <tt>bitset&lt;N&gt;::reference</tt>.
18445<i>unspecified-2</i> is a type that meets the requirements of a constant
18446random access iterator (24.2.5 [random.access.iterators]) whose <tt>value_type</tt>
18447is <tt>bool</tt> and whose reference type is <tt>bool</tt>.
18448</ins>
18449</p>
18450<pre><ins>
18451template&lt;size_t N&gt; <i>unspecified-1</i> begin(bitset&lt;N&gt;&amp;);
18452template&lt;size_t N&gt; <i>unspecified-2</i> begin(const bitset&lt;N&gt;&amp;);
18453</ins>
18454</pre>
18455<blockquote>
18456<ins>2.  Returns: an iterator referencing the first bit in the bitset.</ins>
18457</blockquote>
18458
18459<pre><ins>
18460template&lt;size_t N&gt; <i>unspecified-1</i> end(bitset&lt;N&gt;&amp;);
18461template&lt;size_t N&gt; <i>unspecified-2</i> end(const bitset&lt;N&gt;&amp;);
18462</ins></pre>
18463
18464<blockquote>
18465<ins>3.  Returns: an iterator referencing one past the last bit in the
18466bitset.</ins>
18467</blockquote>
18468</blockquote>
18469</li>
18470</ol>
18471
18472
18473
18474
18475
18476
18477
18478
18479
18480
18481
18482
18483<hr>
18484<h3><a name="1113"></a>1113. <tt>bitset::to_string</tt> could be simplified</h3>
18485<p><b>Section:</b> 20.3.7 [template.bitset] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Tentatively Ready</a>
18486 <b>Submitter:</b> Alisdair Meredith <b>Opened:</b> 2009-05-09  <b>Last modified:</b> 2009-10-26</p>
18487<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#template.bitset">active issues</a> in [template.bitset].</p>
18488<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#template.bitset">issues</a> in [template.bitset].</p>
18489<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Tentatively%20Ready">Tentatively Ready</a> status.</p>
18490<p><b>Discussion:</b></p>
18491<p>
18492In <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#853">853</a> our resolution is changing the signature by adding two
18493defaulting arguments to 3 calls.  In principle, this means that ABI breakage
18494is not an issue, while API is preserved.
18495</p>
18496<p>
18497With that observation, it would be very nice to use the new ability to
18498supply default template parameters to function templates to collapse all 3
18499signatures into 1.  In that spirit, this issue offers an alternative resolution
18500than that of <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#853">853</a>.
18501</p>
18502
18503<p><i>[
18504Batavia (2009-05):
18505]</i></p>
18506
18507<blockquote>
18508Move to Open,
18509and look at the issue again after <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#853">853</a> has been accepted.
18510We further recommend this be deferred until after the next Committee Draft.
18511</blockquote>
18512
18513<p><i>[
185142009-10 post-Santa Cruz:
18515]</i></p>
18516
18517
18518<blockquote>
18519Move to Tentatively Ready.
18520</blockquote>
18521
18522
18523
18524<p><b>Proposed resolution:</b></p>
18525
18526<ol type="A">
18527<li>
18528<p>
18529In 20.3.7 [template.bitset]/1 (class bitset) ammend:
18530</p>
18531<blockquote><pre>template &lt;class charT <ins>= char</ins>,
18532            class traits <ins>= char_traits&lt;charT&gt;</ins>,
18533            class Allocator <ins>= allocator&lt;charT&gt;</ins>&gt; 
18534  basic_string&lt;charT, traits, Allocator&gt;
18535  to_string(charT zero = charT('0'), charT one = charT('1')) const;
18536<del>template &lt;class charT, class traits&gt; 
18537  basic_string&lt;charT, traits, allocator&lt;charT&gt; &gt; to_string() const; 
18538template &lt;class charT&gt; 
18539  basic_string&lt;charT, char_traits&lt;charT&gt;, allocator&lt;charT&gt; &gt; to_string() const; 
18540basic_string&lt;char, char_traits&lt;char&gt;, allocator&lt;char&gt; &gt; to_string() const;</del>
18541</pre></blockquote>
18542</li>
18543<li>
18544<p>
18545In 20.3.7.2 [bitset.members] prior to p35 ammend:
18546</p>
18547<blockquote><pre>template &lt;class charT <ins>= char</ins>,
18548            class traits <ins>= char_traits&lt;charT&gt;</ins>,
18549            class Allocator <ins>= allocator&lt;charT&gt;</ins>&gt; 
18550  basic_string&lt;charT, traits, Allocator&gt;
18551  to_string(charT zero = charT('0'), charT one = charT('1')) const;
18552</pre></blockquote>
18553</li>
18554<li>
18555Strike 20.3.7.2 [bitset.members] paragraphs 37 -&gt; 39 (including signature
18556above 37)
18557</li>
18558</ol>
18559
18560
18561
18562
18563
18564
18565<hr>
18566<h3><a name="1114"></a>1114. Type traits underspecified</h3>
18567<p><b>Section:</b> 20.6 [meta] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Tentatively Ready</a>
18568 <b>Submitter:</b> Daniel Kr�gler <b>Opened:</b> 2009-05-12  <b>Last modified:</b> 2009-10-26</p>
18569<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#meta">issues</a> in [meta].</p>
18570<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Tentatively%20Ready">Tentatively Ready</a> status.</p>
18571<p><b>Discussion:</b></p>
18572
18573<p>
18574Related to <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#975">975</a> and <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1023">1023</a>.
18575</p>
18576
18577<p>
18578The current wording in 20.6.1 [meta.rqmts] is still unclear concerning
18579it's requirements on the type traits classes regarding ambiguities.
18580Specifically it's unclear
18581</p>
18582
18583<ul>
18584<li>
18585if a predicate trait (20.6.4 [meta.unary], 20.6.5 [meta.rel]) could derive from both
18586<tt>true_type</tt>/<tt>false_type</tt>.
18587</li>
18588<li>
18589if any of the type traits (20.6.1 [meta.rqmts], 20.6.4 [meta.unary], 20.6.5 [meta.rel]) could ambiguously derive
18590from the same specified result type.
18591</li>
18592<li>
18593if any of the type traits (20.6.1 [meta.rqmts], 20.6.4 [meta.unary], 20.6.5 [meta.rel]) could derive from other
18594<tt>integral_constant</tt> types making the contained names ambiguous
18595</li>
18596<li>
18597if any of the type traits (20.6.1 [meta.rqmts], 20.6.4 [meta.unary], 20.6.5 [meta.rel]) could have other base
18598classes that contain members hiding the name of the result type members
18599or make the contained member names ambiguous.
18600</li>
18601</ul>
18602
18603<p><i>[
18604Batavia (2009-05):
18605]</i></p>
18606
18607<blockquote>
18608<p>
18609Alisdair would prefer to factor some of the repeated text,
18610but modulo a corner case or two,
18611he believes the proposed wording is otherwise substantially correct.
18612</p>
18613<p>
18614Move to Open.
18615</p>
18616</blockquote>
18617
18618<p><i>[
186192009-10 post-Santa Cruz:
18620]</i></p>
18621
18622
18623<blockquote>
18624Move to Tentatively Ready.
18625</blockquote>
18626
18627
18628
18629<p><b>Proposed resolution:</b></p>
18630<p><i>[
18631The usage of the notion of a <i>BaseCharacteristic</i> below
18632might be
18633useful in other places - e.g. to define the base class relation in
1863420.7.5 [refwrap], 20.7.14 [func.memfn], or 20.7.15.2 [func.wrap.func].
18635In this case it's definition should probably
18636be moved to Clause 17
18637]</i></p>
18638
18639
18640<ol>
18641<li>
18642<p>
18643Change 20.6.1 [meta.rqmts]/1 as indicated:
18644</p>
18645<blockquote>
18646[..] It shall be <tt>DefaultConstructible</tt>, <tt>CopyConstructible</tt>, and publicly
18647<ins>and unambiguously</ins> derived, directly or indirectly, from
18648<ins>its <i>BaseCharacteristic</i>, which is</ins> a specialization of the
18649template <tt>integral_constant</tt> (20.6.3), with the arguments to the template
18650<tt>integral_constant</tt> determined by the requirements for the particular
18651property being described. <ins>The member names of the
18652<i>BaseCharacteristic</i> shall be unhidden and unambiguously
18653available in the <i>UnaryTypeTrait</i>.</ins>
18654</blockquote>
18655</li>
18656<li>
18657<p>
18658Change 20.6.1 [meta.rqmts]/2 as indicated:
18659</p>
18660<blockquote>
18661[..] It shall be <tt>DefaultConstructible</tt>, <tt>CopyConstructible</tt>, and publicly
18662<ins>and unambiguously</ins> derived, directly or indirectly, from
18663<del>an instance</del> <ins>its <i>BaseCharacteristic</i>, which is a
18664specialization</ins> of the template <tt>integral_constant</tt> (20.6.3), with
18665the arguments to the template <tt>integral_constant</tt> determined by the
18666requirements for the particular relationship being described. <ins>The
18667member names of the <i>BaseCharacteristic</i> shall be unhidden
18668and unambiguously available in the <i>BinaryTypeTrait</i>.</ins>
18669</blockquote>
18670</li>
18671<li>
18672<p>
18673Change 20.6.4 [meta.unary]/2 as indicated:
18674</p>
18675<blockquote>
18676Each of these templates shall be a <i>UnaryTypeTrait</i> (20.6.1),
18677<del>publicly derived directly or indirectly from <tt>true_type</tt> if the
18678corresponding condition is true, otherwise from <tt>false_type</tt></del>
18679<ins>where its <i>BaseCharacteristic</i> shall be <tt>true_type</tt> if the
18680corresponding condition is true, otherwise <tt>false_type</tt></ins>.
18681</blockquote>
18682</li>
18683<li>
18684<p>
18685Change 20.6.5 [meta.rel]/2 as indicated:
18686</p>
18687
18688<blockquote>
18689Each of these templates shall be a <i>BinaryTypeTrait</i> (20.6.1),
18690<del>publicly derived directly or indirectly from <tt>true_type</tt> if the
18691corresponding condition is true, otherwise from <tt>false_type</tt></del>
18692<ins>where its <i>BaseCharacteristic</i> shall be <tt>true_type</tt> if the
18693corresponding condition is true, otherwise <tt>false_type</tt></ins>.
18694</blockquote>
18695</li>
18696</ol>
18697
18698
18699
18700
18701
18702
18703<hr>
18704<h3><a name="1115"></a>1115. <tt>va_copy</tt> missing from Standard macros table</h3>
18705<p><b>Section:</b> C.2 [diff.library] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#NAD%20Editorial">Tentatively NAD Editorial</a>
18706 <b>Submitter:</b> Miles Zhao <b>Opened:</b> 2009-05-23  <b>Last modified:</b> 2009-10-26</p>
18707<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#diff.library">issues</a> in [diff.library].</p>
18708<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Tentatively%20NAD%20Editorial">Tentatively NAD Editorial</a> status.</p>
18709<p><b>Discussion:</b></p>
18710<p>
18711In "Table 122 -- Standard macros" of C.2 [diff.library], which lists the 56 macros
18712inherited from C library, <tt>va_copy</tt> seems to be missing. But in
18713"Table 21 -- Header <tt>&lt;cstdarg&gt;</tt> synopsis" (18.10 [support.runtime]), there is.
18714</p>
18715
18716<p><i>[
187172009-10 post-Santa Cruz:
18718]</i></p>
18719
18720
18721<blockquote>
18722Mark as Tentatively NAD Editorial, if Pete disagrees, Howard
18723will move to Tentatively Ready
18724</blockquote>
18725
18726
18727
18728<p><b>Proposed resolution:</b></p>
18729<p>
18730Add <tt>va_copy</tt> to Table 122 -- Standard macros in C.2 [diff.library].
18731</p>
18732
18733
18734
18735
18736
18737<hr>
18738<h3><a name="1118"></a>1118. tuple query APIs do not support cv-qualification</h3>
18739<p><b>Section:</b> 20.5.2.5 [tuple.helper] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
18740 <b>Submitter:</b> Alisdair Meredith <b>Opened:</b> 2009-05-23  <b>Last modified:</b> 2009-10-26</p>
18741<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#tuple.helper">active issues</a> in [tuple.helper].</p>
18742<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#tuple.helper">issues</a> in [tuple.helper].</p>
18743<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
18744<p><b>Discussion:</b></p>
18745<p>
18746The APIs <tt>tuple_size</tt> and <tt>tuple_element</tt> do not support
18747cv-qualified <tt>tuple</tt>s, <tt>pair</tt>s or <tt>array</tt>s.
18748</p>
18749<p>
18750The most generic solution would be to supply partial specializations once
18751for each cv-type in the <tt>tuple</tt> header.  However, requiring this header for
18752cv-qualified <tt>pair</tt>s/<tt>array</tt>s seems unhelpful.  The BSI editorial
18753suggestion (UK-198/US-69,
18754<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2533.html">N2533</a>)
18755to merge <tt>tuple</tt> into <tt>&lt;utility&gt;</tt> would help with <tt>pair</tt>,
18756but not <tt>array</tt>.  That might be resolved by making a dependency between the
18757<tt>&lt;array&gt;</tt> header and <tt>&lt;utility&gt;</tt>, or simply recognising
18758the dependency be fulfilled in a Remark.
18759</p>
18760
18761<p><i>[
187622009-05-24 Daniel adds:
18763]</i></p>
18764
18765
18766<blockquote>
18767<p>
18768All <tt>tuple_size</tt> templates with a base class need to derive publicly, e.g.
18769</p>
18770
18771<blockquote><pre>template &lt;IdentityOf T&gt; class tuple_size&lt; const T &gt; :
18772   <ins>public</ins> tuple_size&lt;T&gt; {};
18773</pre></blockquote>
18774
18775<p>
18776The same applies to the tuple_element class hierarchies.
18777</p>
18778<p>
18779What is actually meant with the comment
18780</p>
18781<blockquote>
18782this solution relies on 'metafunction forwarding' to inherit the
18783nested typename type
18784</blockquote>
18785<p>
18786?
18787</p>
18788<p>
18789I ask, because all base classes are currently unconstrained and their
18790instantiation is invalid in the constrained context of the <tt>tuple_element</tt> partial
18791template specializations.
18792</p>
18793</blockquote>
18794
18795<p><i>[
187962009-05-24 Alisdair adds:
18797]</i></p>
18798
18799
18800<blockquote>
18801<p>
18802I think a better solution might be to ask Pete editorially to change all
18803declarations of tupling APIs to use the struct specifier instead of class.
18804</p>
18805<p>
18806"metafunction forwarding" refers to the MPL metafunction protocol, where a
18807metafunction result is declared as a nested typedef with the name "type",
18808allowing metafunctions to be chained by means of inheritance.  It is a
18809neater syntax than repeatedly declaring a typedef, and inheritance syntax is
18810slightly nicer when it comes to additional typename keywords.
18811</p>
18812<p>
18813The constrained template with an unconstrained base is a good observation
18814though.
18815</p>
18816</blockquote>
18817
18818<p><i>[
188192009-10 post-Santa Cruz:
18820]</i></p>
18821
18822
18823<blockquote>
18824Move to Open, Alisdair to provide wording. Once wording is
18825provided, Howard will move to Review.
18826</blockquote>
18827
18828
18829
18830<p><b>Proposed resolution:</b></p>
18831<p>
18832Add to 20.5.1 [tuple.general] p2 (Header <tt>&lt;tuple&gt;</tt> synopsis)
18833</p>
18834
18835<blockquote><pre>// 20.5.2.3, tuple helper classes:
18836template &lt;IdentityOf T&gt; class tuple_size; // undefined
18837<ins>template &lt;IdentityOf T&gt; class tuple_size&lt; const T &gt; : tuple_size&lt;T&gt; {};</ins>
18838<ins>template &lt;IdentityOf T&gt; class tuple_size&lt; volatile T &gt; : tuple_size&lt;T&gt; {};</ins>
18839<ins>template &lt;IdentityOf T&gt; class tuple_size&lt; const volatile T &gt; : tuple_size&lt;T&gt; {};</ins>
18840
18841template &lt;VariableType... Types&gt; class tuple_size&lt;tuple&lt;Types...&gt; &gt;;
18842
18843template &lt;size_t I, IdentityOf T&gt; class tuple_element; // undefined
18844<ins>template &lt;size_t I, IdentityOf T&gt; class tuple_element&lt;I, const T&gt;;</ins>
18845<ins>template &lt;size_t I, IdentityOf T&gt; class tuple_element&lt;I, volatile T&gt;;</ins>
18846<ins>template &lt;size_t I, IdentityOf T&gt; class tuple_element&lt;I, const volatile T&gt;;</ins>
18847
18848template &lt;size_t I, VariableType... Types&gt;
18849  requires True&lt;(I &lt; sizeof...(Types))&gt; class tuple_element&lt;I, tuple&lt;Types...&gt; &gt;;
18850</pre></blockquote>
18851
18852<p>
18853Add to 20.5.2.5 [tuple.helper]
18854</p>
18855<p><i>[
18856(note that this solution relies on 'metafunction forwarding' to inherit the
18857nested typename type)
18858]</i></p>
18859
18860
18861<blockquote><pre>template &lt;class... Types&gt;
18862class tuple_size&lt;tuple&lt;Types...&gt; &gt;
18863  : public integral_constant&lt;size_t, sizeof...(Types)&gt; { };
18864
18865template &lt;size_t I, class... Types&gt;
18866requires True&lt;(I &lt; sizeof...(Types))&gt;
18867class tuple_element&lt;I, tuple&lt;Types...&gt; &gt; {
18868public:
18869  typedef TI type;
18870};
18871
18872<ins>template &lt;size_t I, IdentityOf T&gt;
18873  class tuple_element&lt;I, const T&gt; : add_const&lt;tuple_element&lt;I,T&gt;&gt; {};</ins>
18874
18875<ins>template &lt;size_t I, IdentityOf T&gt;
18876  class tuple_element&lt;I, volatile T&gt; : add_volatile&lt;tuple_element&lt;I,T&gt;&gt; {};</ins>
18877
18878<ins>template &lt;size_t I, IdentityOf T&gt;
18879  class tuple_element&lt;I, const volatile T&gt; : add_cv&lt;tuple_element&lt;I,T&gt;&gt; {};</ins>
18880</pre></blockquote>
18881
18882
18883
18884
18885
18886<hr>
18887<h3><a name="1119"></a>1119. tuple query APIs do not support references</h3>
18888<p><b>Section:</b> 20.5.2.5 [tuple.helper] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
18889 <b>Submitter:</b> Alisdair Meredith <b>Opened:</b> 2009-05-23  <b>Last modified:</b> 2009-10-26</p>
18890<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#tuple.helper">active issues</a> in [tuple.helper].</p>
18891<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#tuple.helper">issues</a> in [tuple.helper].</p>
18892<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
18893<p><b>Discussion:</b></p>
18894<p>
18895The <tt>tuple</tt> query APIs <tt>tuple_size</tt> and
18896<tt>tuple_element</tt> do not support references-to-tuples.  This can be
18897annoying when a template deduced a parameter type to be a reference,
18898which must be explicitly stripped with <tt>remove_reference</tt> before calling
18899these APIs.
18900</p>
18901<p>
18902I am not proposing a resolution at this point, as there is a
18903combinatorial explosion with lvalue/rvalue references and
18904cv-qualification (see previous issue) that suggests some higher
18905refactoring is in order.  This might be something to kick back over to
18906Core/Evolution.
18907</p>
18908<p>
18909Note that we have the same problem in numeric_limits.
18910</p>
18911
18912<p><i>[
189132009-10 post-Santa Cruz:
18914]</i></p>
18915
18916
18917<blockquote>
18918Move to Open. Alisdair to provide wording.
18919</blockquote>
18920
18921
18922
18923<p><b>Proposed resolution:</b></p>
18924
18925
18926
18927
18928
18929<hr>
18930<h3><a name="1121"></a>1121. Support for multiple arguments</h3>
18931<p><b>Section:</b> 20.4.2 [ratio.arithmetic] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#NAD%20Future">Tentatively NAD Future</a>
18932 <b>Submitter:</b> Alisdair Meredith <b>Opened:</b> 2009-05-25  <b>Last modified:</b> 2009-11-02</p>
18933<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#ratio.arithmetic">issues</a> in [ratio.arithmetic].</p>
18934<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Tentatively%20NAD%20Future">Tentatively NAD Future</a> status.</p>
18935<p><b>Discussion:</b></p>
18936<p>
18937Both add and multiply could sensibly be called with more than two arguments.
18938The variadic template facility makes such declarations simple, and is likely
18939to be frequently wrapped by end users if we do not supply the variant
18940ourselves.
18941</p>
18942<p>
18943We deliberately ignore divide at this point as it is not transitive.
18944Likewise, subtract places special meaning on the first argument so I do not
18945suggest extending that immediately.  Both could be supported with analogous
18946wording to that for add/multiply below.
18947</p>
18948<p>
18949Note that the proposed resolution is potentially incompatible with that
18950proposed for <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#921">921</a>, although the addition of the typedef to ratio would be
18951equally useful.
18952</p>
18953
18954<p><i>[
189552009-10-30 Alisdair adds:
18956]</i></p>
18957
18958
18959<blockquote>
18960<p>
18961The consensus of the group when we reviewed this in Santa Cruz was that
18962<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#921">921</a> would proceed to Ready as planned, and the
18963multi-paramater add/multiply templates should be renamed as
18964<tt>ratio_sum</tt> and <tt>ratio_product</tt> to avoid the problem
18965mixing template aliases with partial specializations.
18966</p>
18967
18968<p>
18969It was also suggested to close this issue as NAD Future as it does not
18970correspond directly to any NB comment.  NBs are free to submit a
18971specific comment (and re-open) in CD2 though.
18972</p>
18973
18974<p>
18975Walter Brown also had concerns on better directing the order of
18976evaluation to avoid overflows if we do proceed for 0x rather than TR1,
18977so wording may not be complete yet.
18978</p>
18979
18980<p><i>[
18981Alisdair updates wording.
18982]</i></p>
18983
18984
18985</blockquote>
18986
18987<p><i>[
189882009-10-30 Howard:
18989]</i></p>
18990
18991
18992<blockquote>
18993Moved to Tentatively NAD Future after 5 positive votes on c++std-lib.
18994</blockquote>
18995
18996
18997
18998<p><b>Proposed resolution:</b></p>
18999
19000<p>
19001Add the following type traits to p3 20.4 [ratio]
19002</p>
19003
19004<blockquote><pre>// ratio arithmetic
19005template &lt;class R1, class R2&gt; struct ratio_add;
19006template &lt;class R1, class R2&gt; struct ratio_subtract;
19007template &lt;class R1, class R2&gt; struct ratio_multiply;
19008template &lt;class R1, class R2&gt; struct ratio_divide;
19009<ins>template &lt;class R1, class ... RList&gt; struct ratio_sum;</ins>
19010<ins>template &lt;class R1, class ... RList&gt; struct ratio_product;</ins>
19011</pre></blockquote>
19012
19013<p>
19014after 20.4.2 [ratio.arithmetic] p1: add
19015</p>
19016
19017<blockquote><pre>template &lt;class R1, class ... RList&gt; struct ratio_sum; // declared, never defined
19018
19019template &lt;class R1&gt; struct ratio_sum&lt;R1&gt; : R1 {};
19020</pre>
19021
19022<blockquote>
19023<i>Requires:</i> <tt>R1</tt> is a specialization of class template <tt>ratio</tt>
19024</blockquote>
19025
19026<pre>template &lt;class R1, class R2, class ... RList&gt; 
19027 struct ratio_sum&lt;R1, R2, RList...&gt;
19028   : ratio_add&lt; R1, ratio_sum&lt;R2, RList...&gt;&gt; {
19029};
19030</pre>
19031
19032<blockquote>
19033<i>Requires:</i> <tt>R1</tt> and each element in parmater pack
19034<tt>RList</tt> is a specialization of class template <tt>ratio</tt>
19035</blockquote>
19036</blockquote>
19037
19038<p>
19039after 20.4.2 [ratio.arithmetic] p3: add
19040</p>
19041
19042<blockquote><pre>template &lt;class R1, class ... RList&gt; struct ratio_product; // declared, never defined
19043
19044template &lt;class R1&gt; struct ratio_product&lt;R1&gt; : R1 {};
19045</pre>
19046
19047<blockquote>
19048<i>Requires:</i> <tt>R1</tt> is a specialization of class template <tt>ratio</tt>
19049</blockquote>
19050
19051<pre>template &lt;class R1, class R2, class ... RList&gt; 
19052 struct ratio_sum&lt;R1, R2, RList...&gt;
19053   : ratio_add&lt; R1, ratio_product&lt;R2, RList...&gt;&gt; {
19054};
19055</pre>
19056
19057<blockquote>
19058<i>Requires:</i> <tt>R1</tt> and each element in parmater pack
19059<tt>RList</tt> is a specialization of class template <tt>ratio</tt>
19060</blockquote>
19061</blockquote>
19062
19063
19064
19065
19066
19067
19068
19069
19070<hr>
19071<h3><a name="1123"></a>1123. no requirement that standard streams be flushed</h3>
19072<p><b>Section:</b> 27.5.2.1.6 [ios::Init] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
19073 <b>Submitter:</b> James Kanze <b>Opened:</b> 2009-05-14  <b>Last modified:</b> 2009-10-20</p>
19074<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#ios::Init">issues</a> in [ios::Init].</p>
19075<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
19076<p><b>Discussion:</b></p>
19077<p>
19078As currently formulated, the standard doesn't require that there 
19079is ever a flush of <tt>cout</tt>, etc.  (This implies, for example, that 
19080the classical hello, world program may have no output.)  In the 
19081current draft
19082(<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2798.pdf">N2798</a>),
19083there is a requirement that the objects 
19084be constructed before <tt>main</tt>, and before the dynamic 
19085initialization of any non-local objects defined after the 
19086inclusion of <tt>&lt;iostream&gt;</tt> in the same translation unit.  The only 
19087requirement that I can find concerning flushing, however, is in 
1908827.5.2.1.6 [ios::Init], where the destructor of the last 
19089<tt>std::ios_base::Init</tt> object flushes.  But there is, as far as I 
19090can see, no guarantee that such an object ever exists. 
19091</p>
19092<p>
19093Also, the wording in  [iostreams.objects] says that:
19094</p>
19095<blockquote>
19096The objects 
19097are constructed and the associations are established at some 
19098time prior to or during the first time an object of class 
19099<tt>ios_base::Init</tt> is constructed, and in any case before the body 
19100of main begins execution.
19101</blockquote>
19102<p>
19103In 27.5.2.1.6 [ios::Init], however, as an 
19104effect of the constructor, it says that
19105</p>
19106<blockquote>
19107If <tt>init_cnt</tt> is zero, 
19108the function stores the value one in <tt>init_cnt</tt>, then constructs 
19109and initializes the objects <tt>cin</tt>, <tt>cout</tt>, <tt>cerr</tt>, <tt>clog</tt> 
19110<tt>wcin</tt>, <tt>wcout</tt>, <tt>wcerr</tt>, and <tt>wclog</tt>"
19111</blockquote>
19112
19113<p>
19114which seems to forbid earlier 
19115construction. 
19116</p>
19117
19118<p>
19119(Note that with these changes, the exposition only "<tt>static 
19120int init_cnt</tt>" in <tt>ios_base::Init</tt> can be dropped.) 
19121</p>
19122<p>
19123Of course, a determined programmer can still inhibit the 
19124flush with things like: 
19125</p>
19126<blockquote><pre>new std::ios_base::Init ;       //  never deleted 
19127</pre></blockquote>
19128<p>
19129or (in a function): 
19130</p>
19131<blockquote><pre>std::ios_base::Init ensureConstruction ; 
19132//  ... 
19133exit( EXIT_SUCCESS ) ; 
19134</pre></blockquote>
19135<p>
19136Perhaps some words somewhere to the effect that all 
19137<tt>std::ios_base::Init</tt> objects should have static lifetime 
19138would be in order. 
19139</p>
19140
19141<p><i>[
191422009 Santa Cruz:
19143]</i></p>
19144
19145
19146<blockquote>
19147Moved to Ready.  Some editorial changes are expected (in addition to the
19148proposed wording) to remove <tt>init_cnt</tt> from <tt>Init</tt>.
19149</blockquote>
19150
19151
19152
19153<p><b>Proposed resolution:</b></p>
19154<p>
19155Change 27.4 [iostream.objects]/2:
19156</p>
19157
19158<blockquote>
19159-2- The objects are constructed and the associations are established at
19160some time prior to or during the first time an object of class
19161<tt>ios_base::Init</tt> is constructed, and in any case before the body
19162of main begins execution.<sup>292</sup> The objects are not destroyed
19163during program execution.<sup>293</sup>
19164<del>If a translation unit includes
19165<tt>&lt;iostream&gt;</tt> or explicitly constructs an
19166<tt>ios_base::Init</tt> object, these stream objects shall be
19167constructed before dynamic initialization of non-local objects defined
19168later in that translation unit.</del>
19169<ins>The results of including <tt>&lt;iostream&gt;</tt> in a translation
19170unit shall be as if <tt>&lt;iostream&gt;</tt> defined an instance of
19171<tt>ios_base::Init</tt> with static lifetime. Similarly, the entire
19172program shall behave as if there were at least one instance of
19173<tt>ios_base::Init</tt> with static lifetime.</ins>
19174</blockquote>
19175
19176<p>
19177Change 27.5.2.1.6 [ios::Init]/3:
19178</p>
19179
19180<blockquote>
19181<pre>Init();
19182</pre>
19183<blockquote>
19184-3- <i>Effects:</i> Constructs an object of class <tt>Init</tt>. 
19185<del>If <tt>init_cnt</tt> is zero, the function stores the value one in
19186<tt>init_cnt</tt>, then constructs and initializes the objects
19187<tt>cin</tt>, <tt>cout</tt>, <tt>cerr</tt>, <tt>clog</tt> (27.4.1),
19188<tt>wcin</tt>, <tt>wcout</tt>, <tt>wcerr</tt>, and <tt>wclog</tt>
19189(27.4.2). In any case, the function then adds one to the value stored in
19190<tt>init_cnt</tt>.</del>
19191<ins>Constructs and initializes the objects <tt>cin</tt>, <tt>cout</tt>,
19192<tt>cerr</tt>, <tt>clog</tt>, <tt>wcin</tt>, <tt>wcout</tt>,
19193<tt>wcerr</tt> and <tt>wclog</tt> if they have not already been
19194constructed and initialized.</ins>
19195</blockquote>
19196</blockquote>
19197
19198<p>
19199Change 27.5.2.1.6 [ios::Init]/4:
19200</p>
19201
19202<blockquote>
19203<pre>~Init();
19204</pre>
19205<blockquote>
19206-4- <i>Effects:</i> Destroys an object of class <tt>Init</tt>.
19207<del>The function subtracts one from the value stored in <tt>init_cnt</tt> and,
19208if the resulting stored value is one,</del>
19209<ins>If there are no other instances of the class still in
19210existance,</ins>
19211calls <tt>cout.flush()</tt>,
19212<tt>cerr.flush()</tt>, <tt>clog.flush()</tt>, <tt>wcout.flush()</tt>,
19213<tt>wcerr.flush()</tt>, <tt>wclog.flush()</tt>.
19214</blockquote>
19215</blockquote>
19216
19217
19218
19219
19220
19221
19222<hr>
19223<h3><a name="1125"></a>1125. ostream_iterator does not work with movable types</h3>
19224<p><b>Section:</b> 24.6.2.2 [ostream.iterator.ops] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
19225 <b>Submitter:</b> Alisdair Meredith <b>Opened:</b> 2009-05-28  <b>Last modified:</b> 2009-05-30</p>
19226<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
19227<p><b>Discussion:</b></p>
19228<p>
19229<tt>ostream_iterator</tt> has not been updated to support moveable types, in a
19230similar manner to the insert iterators.
19231Note that this is not a problem for <tt>ostreambuf_iterator</tt>, as the types it is
19232restricted to dealing with do not support extra-efficient moving.
19233</p>
19234
19235
19236<p><b>Proposed resolution:</b></p>
19237<p>
19238Add second <tt>operator=</tt> overload to class <tt>template ostream_iterator</tt>
19239in 24.6.2 [ostream.iterator], para 2:
19240</p>
19241
19242<blockquote><pre>ostream_iterator&lt;T,charT,traits&gt;&amp; operator=(const T&amp; value);
19243<ins>ostream_iterator&lt;T,charT,traits&gt;&amp; operator=(T&amp;&amp; value);</ins>
19244</pre></blockquote>
19245
19246<p>
19247Add a new paragraph: in 24.6.2.2 [ostream.iterator.ops]:
19248</p>
19249
19250<blockquote>
19251<pre>ostream_iterator&amp; operator=(T&amp;&amp; value);
19252</pre>
19253<blockquote>
19254<p>
19255-2- <i>Effects:</i>
19256</p>
19257<blockquote><pre>*out_stream &lt;&lt; std::move(value);
19258if(delim != 0)
19259  *out_stream &lt;&lt; delim;
19260return (*this);
19261</pre></blockquote>
19262</blockquote>
19263</blockquote>
19264
19265
19266
19267
19268
19269
19270<hr>
19271<h3><a name="1126"></a>1126. <tt>istreambuff_iterator::equal</tt> needs a const &amp; parameter</h3>
19272<p><b>Section:</b> 24.6.3.5 [istreambuf.iterator::equal] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Tentatively Ready</a>
19273 <b>Submitter:</b> Alisdair Meredith <b>Opened:</b> 2009-05-28  <b>Last modified:</b> 2009-11-02</p>
19274<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#istreambuf.iterator::equal">issues</a> in [istreambuf.iterator::equal].</p>
19275<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Tentatively%20Ready">Tentatively Ready</a> status.</p>
19276<p><b>Discussion:</b></p>
19277<p>
19278The <tt>equal</tt> member function of <tt>istreambuf_iterator</tt> is
19279declared <tt>const</tt>, but takes its argument by non-const reference.
19280</p>
19281<p>
19282This is not compatible with the <tt>operator==</tt> free function overload, which is
19283defined in terms of calling <tt>equal</tt> yet takes both arguments by reference to
19284const.
19285</p>
19286
19287<p><i>[
19288The proposed wording is consistent with <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#110">110</a> with status TC1.
19289]</i></p>
19290
19291
19292<p><i>[
192932009-11-02 Howard adds:
19294]</i></p>
19295
19296
19297<blockquote>
19298Set to Tentatively Ready after 5 positive votes on c++std-lib.
19299</blockquote>
19300
19301
19302
19303<p><b>Proposed resolution:</b></p>
19304<p>
19305Ammend in both:<br>
1930624.6.3 [istreambuf.iterator]<br>
1930724.6.3.5 [istreambuf.iterator::equal]<br>
19308</p>
19309
19310<blockquote><pre>bool equal(<ins>const </ins>istreambuf_iterator&amp; b) const;
19311</pre></blockquote>
19312
19313
19314
19315
19316
19317
19318<hr>
19319<h3><a name="1130"></a>1130. <tt>copy_exception</tt> name misleading</h3>
19320<p><b>Section:</b> 18.8.5 [propagation] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Review">Review</a>
19321 <b>Submitter:</b> Peter Dimov <b>Opened:</b> 2009-05-13  <b>Last modified:</b> 2009-10-20</p>
19322<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#propagation">active issues</a> in [propagation].</p>
19323<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#propagation">issues</a> in [propagation].</p>
19324<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Review">Review</a> status.</p>
19325<p><b>Discussion:</b></p>
19326<p>
19327The naming of <tt>std::copy_exception</tt> misleads almost everyone
19328(experts included!) to think that it is the function that copies an
19329<tt>exception_ptr</tt>:
19330</p>
19331
19332<blockquote><pre>exception_ptr p1 = current_exception();
19333exception_ptr p2 = copy_exception( p1 );
19334</pre></blockquote>
19335
19336<p>
19337But this is not at all what it does. The above actually creates an
19338<tt>exception_ptr p2</tt> that contains a copy of <tt>p1</tt>, not of
19339the exception to which <tt>p1</tt> refers!
19340</p>
19341<p>
19342This is, of course, all my fault; in my defence, I used <tt>copy_exception</tt>
19343because I was unable to think of a better name.
19344</p>
19345<p>
19346But I believe that, based on what we've seen so far, <em>any</em> other name would be better.
19347</p>
19348<p>
19349Therefore, I propose <tt>copy_exception</tt> to be renamed to
19350<tt>create_exception</tt>:
19351</p>
19352
19353<blockquote><pre>template&lt;class E&gt; exception_ptr create_exception(E e);
19354</pre></blockquote>
19355
19356<p>
19357with the following explanatory paragraph after it:
19358</p>
19359
19360<blockquote>
19361Creates an <tt>exception_ptr</tt> that refers to a copy of <tt>e</tt>.
19362</blockquote>
19363
19364<p><i>[
193652009-05-13 Daniel adds:
19366]</i></p>
19367
19368
19369<blockquote>
19370<p>
19371What about
19372</p>
19373<blockquote><pre>make_exception_ptr
19374</pre></blockquote>
19375<p>
19376in similarity to <tt>make_pair</tt> and <tt>make_tuple</tt>, <tt>make_error_code</tt> and
19377<tt>make_error_condition</tt>, or <tt>make_shared</tt>? Or, if a stronger symmetry to
19378<tt>current_exception</tt> is preferred:
19379</p>
19380
19381<blockquote><pre>make_exception
19382</pre></blockquote>
19383<p>
19384We have not a single <tt>create_*</tt> function in the library, it was always
19385<tt>make_*</tt> used.
19386</p>
19387</blockquote>
19388
19389<p><i>[
193902009-05-13 Peter adds:
19391]</i></p>
19392
19393
19394<blockquote>
19395<tt>make_exception_ptr</tt> works for me.
19396</blockquote>
19397
19398<p><i>[
193992009-06-02 Thomas J. Gritzan adds:
19400]</i></p>
19401
19402
19403<blockquote>
19404<p>
19405To avoid surprises and unwanted recursion, how about making a call to
19406<tt>std::make_exception_ptr</tt> with an <tt>exception_ptr</tt> illegal?
19407</p>
19408<p>
19409It might work like this:
19410</p>
19411<blockquote><pre>template&lt;class E&gt;
19412exception_ptr make_exception_ptr(E e);
19413template&lt;&gt;
19414exception_ptr make_exception_ptr&lt;exception_ptr&gt;(exception_ptr e) = delete;
19415</pre></blockquote>
19416</blockquote>
19417
19418<p><i>[
194192009 Santa Cruz:
19420]</i></p>
19421
19422
19423<blockquote>
19424Move to Review for the time being. The subgroup thinks this is a good
19425idea, but doesn't want to break compatibility unnecessarily if someone
19426is already shipping this. Let's talk to Benjamin and PJP tomorrow to
19427make sure neither objects.
19428</blockquote>
19429
19430
19431
19432<p><b>Proposed resolution:</b></p>
19433<p>
19434Change 18.8.5 [propagation]:
19435</p>
19436
19437<blockquote>
19438<pre>template&lt;class E&gt; exception_ptr <del>copy_exception</del><ins>make_exception_ptr</ins>(E e);
19439</pre>
19440
19441<blockquote>
19442<p>
19443-11- <i>Effects:</i> <ins>Creates an <tt>exception_ptr</tt> that refers
19444to a copy of <tt>e</tt>,</ins> as if
19445</p>
19446
19447<blockquote><pre>try {
19448  throw e;
19449} catch(...) {
19450  return current_exception();
19451}
19452</pre></blockquote>
19453
19454<p>...</p>
19455</blockquote>
19456
19457</blockquote>
19458
19459
19460
19461
19462
19463
19464<hr>
19465<h3><a name="1131"></a>1131. C++0x does not need <tt>alignment_of</tt></h3>
19466<p><b>Section:</b> 20.6.4.3 [meta.unary.prop] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
19467 <b>Submitter:</b> Niels Dekker <b>Opened:</b> 2009-06-01  <b>Last modified:</b> 2009-06-02</p>
19468<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#meta.unary.prop">active issues</a> in [meta.unary.prop].</p>
19469<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#meta.unary.prop">issues</a> in [meta.unary.prop].</p>
19470<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
19471<p><b>Discussion:</b></p>
19472<p>
19473The <tt>alignment_of</tt> template is no longer necessary, now that the
19474core language will provide <tt>alignof</tt>. Scott Meyers raised this
19475issue at comp.std.c++,
19476<a href="http://groups.google.com/group/comp.std.c++/browse_thread/thread/9b020306e803f08a">C++0x: alignof vs. alignment_of</a>,
19477May 21, 2009.  In a reply, Daniel Kr�gler pointed out that
19478<tt>alignof</tt> was added to the working paper <i>after</i>
19479<tt>alignment_of</tt>. So it appears that <tt>alignment_of</tt> is only
19480part of the current Working Draft 
19481(<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2857.pdf">N2857</a>)
19482because it is in TR1.
19483</p>
19484<p>
19485Having both <tt>alignof</tt> and <tt>alignment_of</tt> would cause
19486unwanted confusion. In general, I think TR1 functionality should not be
19487brought into C++0x if it is entirely redundant with other C++0x language
19488or library features.
19489</p>
19490
19491
19492<p><b>Proposed resolution:</b></p>
19493<p>
19494Remove from Header &lt;type_traits&gt; synopsis 20.6.2 [meta.type.synop]:
19495</p>
19496<blockquote><pre><del>template &lt;class T&gt; struct alignment_of;</del>
19497</pre></blockquote>
19498
19499<p>
19500Remove the first row of Table 34 ("Type property queries"), from
19501Type properties 20.6.4.3 [meta.unary.prop]:
19502</p>
19503<blockquote>
19504<table border="1">
19505<caption>Table 34 -- Type property queries</caption>
19506<tbody><tr>
19507<td><del><tt>template &lt;class T&gt; struct alignment_of;</tt></del></td>
19508<td><del><tt>alignof(T)</tt>.</del><br>
19509<del><i>Precondition:</i> <tt>T</tt> shall be a complete type, a reference
19510type, or an array of unknown bound, but shall not be a function type or
19511(possibly cv-qualified) <tt>void</tt>.</del>
19512</td>
19513</tr>
19514</tbody></table>
19515</blockquote>
19516
19517<p>
19518Change text in Table 41 ("Other transformations"), from Other
19519transformations 20.6.7 [meta.trans.other], as follows:
19520</p>
19521<blockquote>
19522<table border="1">
19523<caption>Table 41 -- Other transformations</caption>
19524<tbody><tr><td>...</td>
19525<td>
19526 Align shall be equal to <tt>
19527 <del>alignment_of&lt;T&gt;::value</del>
19528 <ins>alignof(T)</ins>
19529 </tt> for some type <tt>T</tt> or to <i>default-alignment</i>.
19530</td>
19531<td>...</td>
19532</tr></tbody></table>
19533</blockquote>
19534
19535
19536
19537
19538
19539<hr>
19540<h3><a name="1133"></a>1133. Does N2844 break current specification of list::splice?</h3>
19541<p><b>Section:</b> 23.3.3.5 [forwardlist.ops], 23.3.4.4 [list.ops] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
19542 <b>Submitter:</b> Alisdair Meredith <b>Opened:</b> 2009-05-09  <b>Last modified:</b> 2009-10-27</p>
19543<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#forwardlist.ops">issues</a> in [forwardlist.ops].</p>
19544<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
19545<p><b>Discussion:</b></p>
19546<p>
19547IIUC,
19548<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2844.html">N2844</a>
19549means that lvalues will no longer bind to rvalue references.
19550Therefore, the current specification of <tt>list::splice</tt> (list
19551operations 23.3.4.4 [list.ops]) will be a breaking change of behaviour for existing
19552programs.  That is because we changed the signature to swallow via an rvalue
19553reference rather than the lvalue reference used in 03.
19554</p>
19555<p>
19556Retaining this form would be safer, requiring an explicit move when splicing
19557from lvalues.  However, this will break existing programs.
19558We have the same problem with <tt>forward_list</tt>, although without the risk of
19559breaking programs so here it might be viewed as a positive feature.
19560</p>
19561<p>
19562The problem signatures:
19563</p>
19564<blockquote><pre>void splice_after(const_iterator position, forward_list&lt;T,Alloc&gt;&amp;&amp; x);
19565void splice_after(const_iterator position, forward_list&lt;T,Alloc&gt;&amp;&amp; x,
19566                  const_iterator i);
19567void splice_after(const_iterator position, forward_list&lt;T,Alloc&gt;&amp;&amp; x,
19568                  const_iterator first, const_iterator last);
19569
19570void splice(const_iterator position, list&lt;T,Alloc&gt;&amp;&amp; x);
19571void splice(const_iterator position, list&lt;T,Alloc&gt;&amp;&amp; x,
19572            const_iterator i);
19573void splice(const_iterator position, list&lt;T,Alloc&gt;&amp;&amp; x,
19574            const_iterator first, const_iterator last);
19575</pre></blockquote>
19576
19577<b>Possible resolutions:</b>
19578
19579<p>
19580Option A.   Add an additional (non-const) lvalue-reference
19581overload in each case
19582</p>
19583<p>
19584Option B.   Change rvalue reference back to (non-const)
19585lvalue-reference overload in each case
19586</p>
19587<p>
19588Option C.   Add an additional (non-const) lvalue-reference
19589overload in just the <tt>std::list</tt> cases
19590</p>
19591<p>
19592I think (B) would be very unfortunate, I really like the <tt>forward_list</tt>
19593behaviour in (C) but feel (A) is needed for consistency.
19594</p>
19595<p>
19596My actual preference would be NAD, ship with this as a breaking change as it
19597is a more explicit interface.  I don't think that will fly though!
19598</p>
19599
19600<p>
19601See the thread starting with c++std-lib-23725 for more discussion.
19602</p>
19603
19604<p><i>[
196052009-10-27 Christopher Jefferson provides proposed wording for Option C.
19606]</i></p>
19607
19608
19609
19610<p><b>Proposed resolution:</b></p>
19611<p>
19612In 23.3.4 [list]
19613</p>
19614
19615<p>
19616Add lvalue overloads before rvalue ones:
19617</p>
19618
19619<blockquote><pre><ins>void splice(const_iterator position, list&lt;T,Allocator&gt;&amp; x);</ins>
19620void splice(const_iterator position, list&lt;T,Allocator&gt;&amp;&amp; x);
19621<ins>void splice(const_iterator position, list&lt;T,Allocator&gt;&amp; x, const_iterator i);</ins>
19622void splice(const_iterator position, list&lt;T,Allocator&gt;&amp;&amp; x, const_iterator i);
19623<ins>void splice(const_iterator position, list&lt;T,Allocator&gt;&amp; x,
19624            const_iterator first, const_iterator last);</ins>
19625void splice(const_iterator position, list&lt;T,Allocator&gt;&amp;&amp; x,
19626            const_iterator first, const_iterator last);
19627</pre></blockquote>
19628
19629<p>
19630In 23.3.4.4 [list.ops], similarly add lvalue overload before each rvalue one:
19631</p>
19632<p>
19633(After paragraph 2)
19634</p>
19635
19636<blockquote><pre><ins>void splice(const_iterator position, list&lt;T,Allocator&gt;&amp; x);</ins>
19637void splice(const_iterator position, list&lt;T,Allocator&gt;&amp;&amp; x);
19638</pre></blockquote>
19639
19640<p>
19641(After paragraph 6)
19642</p>
19643
19644<blockquote><pre><ins>void splice(const_iterator position, list&lt;T,Allocator&gt;&amp; x, const_iterator i);</ins>
19645void splice(const_iterator position, list&lt;T,Allocator&gt;&amp;&amp; x, const_iterator i);
19646</pre></blockquote>
19647
19648<p>
19649(After paragraph 10)
19650</p>
19651
19652<blockquote><pre><ins>void splice(const_iterator position, list&lt;T,Allocator&gt;&amp; x,
19653            const_iterator first, const_iterator last);</ins>
19654void splice(const_iterator position, list&lt;T,Allocator&gt;&amp;&amp; x,
19655            const_iterator first, const_iterator last);
19656</pre></blockquote>
19657
19658
19659
19660
19661
19662
19663<hr>
19664<h3><a name="1134"></a>1134. Redundant specification of stdint.h, fenv.h, tgmath.h, and maybe complex.h</h3>
19665<p><b>Section:</b> 18.4.2 [stdinth], 26.3.2 [fenv], 26.8 [c.math], 26.4.11 [cmplxh] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
19666 <b>Submitter:</b> Robert Klarer <b>Opened:</b> 2009-05-26  <b>Last modified:</b> 2009-10-20</p>
19667<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
19668<p><b>Discussion:</b></p>
19669<p>
19670This is probably editorial.
19671</p>
19672<p>
19673The following items should be removed from the draft, because they're
19674redundant with Annex D, and they arguably make some *.h headers
19675non-deprecated:
19676</p>
19677<p>
1967818.4.2 [stdinth] (regarding <tt>&lt;stdint.h&gt;</tt>) 
19679</p>
19680<p>
1968126.3.2 [fenv] (regarding <tt>&lt;fenv.h&gt;</tt>
19682</p>
19683<p>
19684Line 3 of 26.8 [c.math] (regarding <tt>&lt;tgmath.h&gt;</tt>) 
19685</p>
19686<p>
1968726.4.11 [cmplxh] (regarding <tt>&lt;complex.h&gt;</tt>, though the note in this subclause is not redundant) 
19688</p>
19689
19690<p><i>[
196912009-06-10 Ganesh adds:
19692]</i></p>
19693
19694
19695<blockquote>
19696While searching for <tt>stdint</tt> in the CD, I found that <tt>&lt;stdint.h&gt;</tt> is also
19697mentioned in 3.9.1 [basic.fundamental] /5. It guess it should refer to
19698<tt>&lt;cstdint&gt;</tt> instead.
19699</blockquote>
19700
19701<p><i>[
197022009 Santa Cruz:
19703]</i></p>
19704
19705
19706<blockquote>
19707Real issue. Maybe just editorial, maybe not. Move to Ready.
19708</blockquote>
19709
19710
19711
19712<p><b>Proposed resolution:</b></p>
19713<p>
19714Remove the section 18.4.2 [stdinth].
19715</p>
19716<p>
19717Remove the section 26.3.2 [fenv].
19718</p>
19719<p>
19720Remove 26.8 [c.math], p3:
19721</p>
19722
19723<blockquote>
19724<del>-3- The header <tt>&lt;tgmath.h&gt;</tt> effectively includes the headers <tt>&lt;complex.h&gt;</tt>
19725and <tt>&lt;math.h&gt;</tt>.</del>
19726</blockquote>
19727<p>
19728Remove the section 26.4.11 [cmplxh].
19729</p>
19730
19731
19732
19733
19734
19735<hr>
19736<h3><a name="1135"></a>1135. <tt>exception_ptr</tt> should support contextual conversion to <tt>bool</tt></h3>
19737<p><b>Section:</b> 18.8.5 [propagation] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
19738 <b>Submitter:</b> Daniel Kr�gler <b>Opened:</b> 2007-06-06  <b>Last modified:</b> 2009-10-20</p>
19739<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#propagation">active issues</a> in [propagation].</p>
19740<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#propagation">issues</a> in [propagation].</p>
19741<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
19742<p><b>Discussion:</b></p>
19743<p>
19744As of
19745<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2857.pdf">N2857</a>
1974618.8.5 [propagation]/5, the implementation-defined type
19747<tt>exception_ptr</tt> does provide the following ways to check whether
19748it is a null value:
19749</p>
19750<blockquote><pre>void f(std::exception_ptr p) {
19751  p == nullptr;
19752  p == 0;
19753  p == exception_ptr();
19754}
19755</pre></blockquote>
19756<p>
19757This is rather cumbersome way of checking for the null value
19758and I suggest to require support for evaluation in a boolean
19759context like so:
19760</p>
19761
19762<blockquote><pre>void g(std::exception_ptr p) {
19763  if (p) {}
19764  !p;
19765}
19766</pre></blockquote>
19767
19768<p><i>[
197692009 Santa Cruz:
19770]</i></p>
19771
19772
19773<blockquote>
19774Move to Ready. Note to editor: considering putting in a cross-reference
19775to 4 [conv], paragraph 3, which defines the phrase
19776"contextually converted to <tt>bool</tt>".
19777</blockquote>
19778
19779
19780
19781<p><b>Proposed resolution:</b></p>
19782<p>
19783In section 18.8.5 [propagation] insert a new paragraph between p.5 and p.6:
19784</p>
19785
19786<blockquote>
19787<ins>
19788An object <tt>e</tt> of type <tt>exception_ptr</tt> can be contextually converted to <tt>bool</tt>.
19789The effect shall be as if <tt>e != exception_ptr()</tt> had been evaluated in place
19790of <tt>e</tt>. There shall be no implicit conversion to arithmetic type, to
19791enumeration type or to pointer type.
19792</ins>
19793</blockquote>
19794
19795
19796
19797
19798
19799<hr>
19800<h3><a name="1136"></a>1136. Incomplete specification of <tt>nested_exception::rethrow_nested()</tt></h3>
19801<p><b>Section:</b> 18.8.6 [except.nested] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
19802 <b>Submitter:</b> Daniel Kr�gler <b>Opened:</b> 2007-06-06  <b>Last modified:</b> 2009-10-20</p>
19803<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#except.nested">active issues</a> in [except.nested].</p>
19804<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#except.nested">issues</a> in [except.nested].</p>
19805<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
19806<p><b>Discussion:</b></p>
19807<p>
19808It was recently mentioned in a newsgroup article
19809<a href="http://groups.google.de/group/comp.std.c++/msg/f82022aff68edf3d">http://groups.google.de/group/comp.std.c++/msg/f82022aff68edf3d</a>
19810that the specification of the member function <tt>rethrow_nested()</tt> of the
19811class <tt>nested_exception</tt> is incomplete, specifically it remains unclear
19812what happens, if member <tt>nested_ptr()</tt> returns a null value. In
1981318.8.6 [except.nested] we find only the following paragraph related to that:
19814</p>
19815<blockquote><pre>void rethrow_nested() const; // [[noreturn]]
19816</pre>
19817<blockquote>
19818-4- <i>Throws:</i> the stored exception captured by this <tt>nested_exception</tt> object.
19819</blockquote>
19820</blockquote>
19821<p>
19822This is a problem, because it is possible to create an object of
19823<tt>nested_exception</tt> with exactly such a state, e.g.
19824</p>
19825<blockquote><pre>#include &lt;exception&gt;
19826#include &lt;iostream&gt;
19827
19828int main() try {
19829  std::nested_exception e; // OK, calls current_exception() and stores it's null value
19830  e.rethrow_nested(); // ?
19831  std::cout &lt;&lt; "A" &lt;&lt; std::endl;
19832}
19833catch(...) {
19834  std::cout &lt;&lt; "B" &lt;&lt; std::endl;
19835}
19836</pre></blockquote>
19837<p>
19838I suggest to follow the proposal of the reporter, namely to invoke
19839<tt>terminate()</tt> if <tt>nested_ptr()</tt> return a null value of <tt>exception_ptr</tt> instead
19840of relying on the fallback position of undefined behavior. This would
19841be consistent to the behavior of a <tt>throw;</tt> statement when no
19842exception is being handled.
19843</p>
19844
19845<p><i>[
198462009 Santa Cruz:
19847]</i></p>
19848
19849
19850<blockquote>
19851Move to Ready.
19852</blockquote>
19853
19854
19855
19856<p><b>Proposed resolution:</b></p>
19857<p>
19858Change around 18.8.6 [except.nested]/4 as indicated:
19859</p>
19860<blockquote>
19861<p>
19862-4- <i>Throws:</i> the stored exception captured by this <tt>nested_exception</tt>
19863object<ins>, if <tt>nested_ptr() != nullptr</tt></ins>
19864</p>
19865<p>
19866<ins>- <i>Remarks:</i> If <tt>nested_ptr() == nullptr</tt>, <tt>terminate()</tt>
19867shall be called.</ins>
19868</p>
19869</blockquote>
19870
19871
19872
19873
19874
19875<hr>
19876<h3><a name="1137"></a>1137. Return type of <tt>conj</tt> and <tt>proj</tt></h3>
19877<p><b>Section:</b> 26.4.9 [cmplx.over] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
19878 <b>Submitter:</b> Marc Steinbach <b>Opened:</b> 2009-06-11  <b>Last modified:</b> 2009-06-27</p>
19879<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#cmplx.over">issues</a> in [cmplx.over].</p>
19880<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
19881<p><b>Discussion:</b></p>
19882<p>
19883In clause 1, the Working Draft 
19884(<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2857.pdf">N2857</a>)
19885specifies overloads of the
19886functions
19887</p>
19888<blockquote><pre>arg, conj, imag, norm, proj, real
19889</pre></blockquote>
19890<p>
19891for non-complex arithmetic types (<tt>float</tt>, <tt>double</tt>,
19892<tt>long double</tt>, and integers).
19893The only requirement (clause 2) specifies effective type promotion of arguments.
19894</p>
19895<p>
19896I strongly suggest to add the following requirement on the return types:
19897</p>
19898<blockquote>
19899All the specified overloads must return real (i.e., non-complex) values,
19900specifically, the nested <tt>value_type</tt> of effectively promoted arguments.
19901</blockquote>
19902
19903<p>
19904(This has no effect on <tt>arg</tt>, <tt>imag</tt>, <tt>norm</tt>, <tt>real</tt>:
19905they are real-valued anyway.)
19906</p>
19907<p><b>Rationale:</b></p>
19908<p>
19909Mathematically, <tt>conj()</tt> and <tt>proj()</tt>, like the transcendental functions, are
19910complex-valued in general but map the (extended) real line to itself.
19911In fact, both functions act as identity on the reals.
19912A typical user will expect <tt>conj()</tt> and <tt>proj()</tt> to preserve this essential
19913mathematical property in the same way as <tt>exp()</tt>, <tt>sin()</tt>, etc.
19914A typical use of <tt>conj()</tt>, e.g., is the generic scalar product of n-vectors:
19915</p>
19916
19917<blockquote><pre>template&lt;typename T&gt;
19918inline T
19919scalar_product(size_t n, T const* x, T const* y) {
19920  T result = 0;
19921  for (size_t i = 0; i &lt; n; ++i)
19922    result += x[i] * std::conj(y[i]);
19923  return result;
19924}
19925</pre></blockquote>
19926<p>
19927This will work equally well for real and complex floating-point types <tt>T</tt> if
19928<tt>conj()</tt> returns <tt>T</tt>. It will not work with real types if <tt>conj()</tt>
19929returns complex values.
19930</p>
19931<p>
19932Instead, the implementation of <tt>scalar_product</tt> becomes either less efficient
19933and less useful (if a complex result is always returned), or unnecessarily
19934complicated (if overloaded versions with proper return types are defined).
19935In the second case, the real-argument overload of <tt>conj()</tt> cannot be used.
19936In fact, it must be avoided.
19937</p>
19938<p>
19939Overloaded <tt>conj()</tt> and <tt>proj()</tt> are principally needed in generic programming.
19940All such use cases will benefit from the proposed return type requirement,
19941in a similar way as the <tt>scalar_product</tt> example.
19942The requirement will not harm use cases where a complex return value
19943is expected, because of implicit conversion to complex.
19944Without the proposed return type guarantee, I find overloaded versions
19945of <tt>conj()</tt> and <tt>proj()</tt> not only useless but actually troublesome.
19946</p>
19947
19948
19949
19950<p><b>Proposed resolution:</b></p>
19951<p>
19952Insert a new paragraph after 26.4.9 [cmplx.over]/2:
19953</p>
19954
19955<blockquote>
19956<ins>
19957All of the specified overloads shall have a return type which is the nested <tt>value_type</tt> of
19958the effectively promoted arguments.
19959</ins>
19960</blockquote>
19961
19962
19963
19964
19965
19966<hr>
19967<h3><a name="1138"></a>1138. unusual return value for operator+</h3>
19968<p><b>Section:</b> 21.4.8.1 [string::op+] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Tentatively Ready</a>
19969 <b>Submitter:</b> Alisdair Meredith <b>Opened:</b> 2009-06-12  <b>Last modified:</b> 2009-11-05</p>
19970<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Tentatively%20Ready">Tentatively Ready</a> status.</p>
19971<p><b>Discussion:</b></p>
19972<p>
19973Many of the <tt>basic_string operator+</tt> overloads return an rvalue-reference.  Is
19974that really intended?
19975</p>
19976<p>
19977I'm considering it might be a mild performance tweak to avoid making
19978un-necessary copies of a cheaply movable type, but it opens risk to dangling
19979references in code like:
19980</p>
19981
19982<blockquote><pre>auto &amp;&amp; s = string{"x"} + string{y};
19983</pre></blockquote>
19984
19985<p>
19986and I'm not sure about:
19987</p>
19988
19989<blockquote><pre>auto s = string{"x"} + string{y};
19990</pre></blockquote>
19991
19992<p><i>[
199932009-10-11 Howard updated <i>Returns:</i> clause for each of these.
19994]</i></p>
19995
19996
19997<p><i>[
199982009-11-05 Howard adds:
19999]</i></p>
20000
20001
20002<blockquote>
20003Moved to Tentatively Ready after 5 positive votes on c++std-lib.
20004</blockquote>
20005
20006
20007<p><b>Proposed resolution:</b></p>
20008<p>
20009Strike the <tt>&amp;&amp;</tt> from the return type in the following function
20010signatures:
20011</p>
20012
20013<blockquote>
20014<p>
2001521.3 [string.classes] p2 Header Synopsis
20016</p>
20017
20018<blockquote><pre>template&lt;class charT, class traits, class Allocator&gt;
20019  basic_string&lt;charT,traits,Allocator&gt;<del>&amp;&amp;</del>
20020    operator+(basic_string&lt;charT,traits,Allocator&gt;&amp;&amp; lhs,
20021              const basic_string&lt;charT,traits,Allocator&gt;&amp; rhs);
20022
20023template&lt;class charT, class traits, class Allocator&gt;
20024  basic_string&lt;charT,traits,Allocator&gt;<del>&amp;&amp;</del>
20025    operator+(const basic_string&lt;charT,traits,Allocator&gt;&amp; lhs,
20026              basic_string&lt;charT,traits,Allocator&gt;&amp;&amp; rhs);
20027
20028template&lt;class charT, class traits, class Allocator&gt;
20029  basic_string&lt;charT,traits,Allocator&gt;<del>&amp;&amp;</del>
20030    operator+(basic_string&lt;charT,traits,Allocator&gt;&amp;&amp; lhs,
20031              basic_string&lt;charT,traits,Allocator&gt;&amp;&amp; rhs);
20032
20033
20034template&lt;class charT, class traits, class Allocator&gt;
20035  basic_string&lt;charT,traits,Allocator&gt;<del>&amp;&amp;</del>
20036    operator+(const charT* lhs,
20037              basic_string&lt;charT,traits,Allocator&gt;&amp;&amp; rhs);
20038
20039template&lt;class charT, class traits, class Allocator&gt;
20040  basic_string&lt;charT,traits,Allocator&gt;<del>&amp;&amp;</del>
20041    operator+(charT lhs, basic_string&lt;charT,traits,Allocator&gt;&amp;&amp; rhs);
20042
20043template&lt;class charT, class traits, class Allocator&gt;
20044  basic_string&lt;charT,traits,Allocator&gt;<del>&amp;&amp;</del>
20045    operator+(basic_string&lt;charT,traits,Allocator&gt;&amp;&amp; lhs,
20046              const charT* rhs);
20047
20048template&lt;class charT, class traits, class Allocator&gt;
20049  basic_string&lt;charT,traits,Allocator&gt;<del>&amp;&amp;</del>
20050    operator+(basic_string&lt;charT,traits,Allocator&gt;&amp;&amp; lhs, charT rhs);
20051</pre></blockquote>
20052
20053<p>
2005421.4.8.1 [string::op+]
20055</p>
20056
20057<blockquote><pre>template&lt;class charT, class traits, class Allocator&gt;
20058  basic_string&lt;charT,traits,Allocator&gt;<del>&amp;&amp;</del>
20059    operator+(basic_string&lt;charT,traits,Allocator&gt;&amp;&amp; lhs,
20060              const basic_string&lt;charT,traits,Allocator&gt;&amp; rhs);
20061</pre>
20062<blockquote>
20063<i>Returns:</i> <tt><ins>std::move(</ins>lhs.append(rhs)<ins>)</ins></tt>
20064</blockquote>
20065<pre>template&lt;class charT, class traits, class Allocator&gt;
20066  basic_string&lt;charT,traits,Allocator&gt;<del>&amp;&amp;</del>
20067    operator+(const basic_string&lt;charT,traits,Allocator&gt;&amp; lhs,
20068              basic_string&lt;charT,traits,Allocator&gt;&amp;&amp; rhs);
20069</pre>
20070<blockquote>
20071<i>Returns:</i> <tt><ins>std::move(</ins>rhs.insert(0, lhs)<ins>)</ins></tt>
20072</blockquote>
20073<pre>template&lt;class charT, class traits, class Allocator&gt;
20074  basic_string&lt;charT,traits,Allocator&gt;<del>&amp;&amp;</del>
20075    operator+(basic_string&lt;charT,traits,Allocator&gt;&amp;&amp; lhs,
20076              basic_string&lt;charT,traits,Allocator&gt;&amp;&amp; rhs);
20077</pre>
20078<blockquote>
20079<i>Returns:</i> <tt><ins>std::move(</ins>lhs.append(rhs)<ins>)</ins></tt> [<i>Note:</i> Or equivalently
20080<tt><ins>std::move(</ins>rhs.insert(0, lhs)<ins>)</ins></tt> &#8212; <i>end note</i>]
20081</blockquote>
20082<pre>template&lt;class charT, class traits, class Allocator&gt;
20083  basic_string&lt;charT,traits,Allocator&gt;<del>&amp;&amp;</del>
20084    operator+(const charT* lhs,
20085              basic_string&lt;charT,traits,Allocator&gt;&amp;&amp; rhs);
20086</pre>
20087<blockquote>
20088<i>Returns:</i> <tt><ins>std::move(</ins>rhs.insert(0, lhs)<ins>)</ins></tt>.
20089</blockquote>
20090<pre>template&lt;class charT, class traits, class Allocator&gt;
20091  basic_string&lt;charT,traits,Allocator&gt;<del>&amp;&amp;</del>
20092    operator+(charT lhs, basic_string&lt;charT,traits,Allocator&gt;&amp;&amp; rhs);
20093</pre>
20094<blockquote>
20095<i>Returns:</i> <tt><ins>std::move(</ins>rhs.insert(0, 1, lhs)<ins>)</ins></tt>.
20096</blockquote>
20097<pre>template&lt;class charT, class traits, class Allocator&gt;
20098  basic_string&lt;charT,traits,Allocator&gt;<del>&amp;&amp;</del>
20099    operator+(basic_string&lt;charT,traits,Allocator&gt;&amp;&amp; lhs,
20100              const charT* rhs);
20101</pre>
20102<blockquote>
20103<i>Returns:</i> <tt><ins>std::move(</ins>lhs.append(rhs)<ins>)</ins></tt>.
20104</blockquote>
20105<pre>template&lt;class charT, class traits, class Allocator&gt;
20106  basic_string&lt;charT,traits,Allocator&gt;<del>&amp;&amp;</del>
20107    operator+(basic_string&lt;charT,traits,Allocator&gt;&amp;&amp; lhs, charT rhs);
20108</pre>
20109<blockquote>
20110<i>Returns:</i> <tt><ins>std::move(</ins>lhs.append(1, rhs)<ins>)</ins></tt>.
20111</blockquote>
20112</blockquote>
20113
20114</blockquote>
20115
20116
20117
20118
20119
20120
20121<hr>
20122<h3><a name="1144"></a>1144. "thread safe" is undefined</h3>
20123<p><b>Section:</b> 18.5 [support.start.term] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
20124 <b>Submitter:</b> LWG <b>Opened:</b> 2009-06-16  <b>Last modified:</b> 2009-10-20</p>
20125<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#support.start.term">issues</a> in [support.start.term].</p>
20126<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
20127<p><b>Discussion:</b></p>
20128
20129<p><b>Addresses UK 187</b></p>
20130
20131<p>
20132The term "thread safe" is not defined nor used in this context
20133anywhere else in the standard.
20134</p>
20135
20136<p><b>Suggested action:</b></p>
20137<p>
20138Clarify the meaning of "thread safe".
20139</p>
20140
20141<p><i>[
201422009 Santa Cruz:
20143]</i></p>
20144
20145
20146<blockquote>
20147<p>
20148The "thread safe" language has already been change in the WP. It was
20149changed to "happen before", but the current WP text is still a little
20150incomplete: "happen before" is binary, but the current WP text only
20151mentions one thing.
20152</p>
20153<p>
20154Move to Ready.
20155</p>
20156</blockquote>
20157
20158
20159
20160<p><b>Proposed resolution:</b></p>
20161<p>
20162For the following functions in 18.5 [support.start.term].
20163</p>
20164<blockquote><pre><code>
20165extern "C" int at_quick_exit(void (*f)(void));
20166extern "C++" int at_quick_exit(void (*f)(void));
20167</code></pre></blockquote>
20168
20169<p>
20170Edit paragraph 10 as follows.
20171The intent is
20172to provide the other half of the happens before relation;
20173to note indeterminate ordering;
20174and to clean up some formatting.
20175</p>
20176<blockquote><p>
20177<i>Effects:</i>
20178The <code>at_quick_exit()</code> functions
20179register the function pointed to by <code>f</code>
20180to be called without arguments when <code>quick_exit</code> is called.
20181It is unspecified whether a call to <code>at_quick_exit()</code>
20182that does not <del>happen-before</del> <ins>happen before</ins> (1.10)
20183<ins>all calls to <code>quick_exit</code></ins>
20184will succeed.
20185[<i>Note:</i>
20186the <code>at_quick_exit()</code> functions
20187shall not introduce a data race (17.6.4.7).
20188<del>exitnote</del>
20189<ins>&#8212;<i>end note</i>]</ins>
20190<ins>
20191[<i>Note:</i>
20192The order of registration may be indeterminate
20193if <code>at_quick_exit</code> was called from more than one thread.
20194&#8212;<i>end note</i>]
20195</ins>
20196[<i>Note:</i> The <code>at_quick_exit</code> registrations
20197are distinct from the <code>atexit</code> registrations,
20198and applications may need to call both registration functions
20199with the same argument.
20200&#8212;<i>end note</i>]
20201</p></blockquote>
20202
20203<p>
20204For the following function.
20205</p>
20206<blockquote><pre><code>
20207void quick_exit [[noreturn]] (int status)
20208</code></pre></blockquote>
20209
20210<p>
20211Edit paragraph 13 as follows.
20212The intent is to note that thread-local variables may be different.
20213</p>
20214<blockquote><p>
20215<i>Effects:</i>
20216Functions registered by calls to <code>at_quick_exit</code>
20217are called in the reverse order of their registration,
20218except that a function shall be called
20219after any previously registered functions
20220that had already been called at the time it was registered.
20221Objects shall not be destroyed as a result of calling <code>quick_exit</code>.
20222If control leaves a registered function called by <code>quick_exit</code>
20223because the function does not provide a handler for a thrown exception,
20224<code>terminate()</code> shall be called.
20225<ins>
20226[<i>Note:</i>
20227Functions registered by one thread may be called by any thread,
20228and hence should not rely on the identity of thread-storage-duration objects.
20229&#8212;<i>end note</i>]
20230</ins>
20231After calling registered functions,
20232<code>quick_exit</code> shall call <code>_Exit(status)</code>.
20233[<i>Note:</i>
20234The standard file buffers are not flushed.
20235See: ISO C 7.20.4.4.
20236&#8212;<i>end note</i>]
20237</p></blockquote>
20238
20239
20240
20241
20242
20243<hr>
20244<h3><a name="1151"></a>1151. Behavior of the library in the presence of threads is incompletely specified</h3>
20245<p><b>Section:</b> 17 [library] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
20246 <b>Submitter:</b> LWG <b>Opened:</b> 2009-06-28  <b>Last modified:</b> 2009-10-20</p>
20247<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#library">active issues</a> in [library].</p>
20248<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#library">issues</a> in [library].</p>
20249<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
20250<p><b>Discussion:</b></p>
20251<p><b>Addresses US 63</b></p>
20252
20253   <p><b>Description</b></p>
20254        <p>The behavior of the library in the presence of threads
20255        is incompletely specified.</p>
20256        <p>For example, if thread 1 assigns to <tt>X</tt>, then writes data
20257        to file <tt>f</tt>, which is read by thread 2, and then accesses
20258        variable <tt>X</tt>, is thread 2 guaranteed to be able to see the
20259        value assigned to <tt>X</tt> by thread 1? In other words, does the
20260        write of the data "happen before" the read?</p>
20261        <p>Another example: does simultaneous access using <tt>operator
20262        at()</tt> to different characters in the same non-const string
20263        really introduce a data race?</p>
20264<p><b>Suggestion</b></p>
20265<p><b>Notes</b></p><p>17 SG: should go to threads group; misclassified in document
20266</p>
20267
20268    <p>Concurrency SG: Create an issue. Hans will look into it.</p>
20269
20270<p><i>[
202712009 Santa Cruz:
20272]</i></p>
20273
20274
20275<blockquote>
20276Move to "Open". Hans and the rest of the concurrency working group will
20277study this. We can't make progress without a thorough review and a
20278paper.
20279</blockquote>
20280
20281
20282
20283<p><b>Proposed resolution:</b></p>
20284
20285
20286
20287
20288
20289<hr>
20290<h3><a name="1152"></a>1152. expressions parsed differently than intended</h3>
20291<p><b>Section:</b> 22.4.2.2.2 [facet.num.put.virtuals] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Tentatively Ready</a>
20292 <b>Submitter:</b> Seungbeom Kim <b>Opened:</b> 2009-06-27  <b>Last modified:</b> 2009-10-28</p>
20293<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#facet.num.put.virtuals">active issues</a> in [facet.num.put.virtuals].</p>
20294<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#facet.num.put.virtuals">issues</a> in [facet.num.put.virtuals].</p>
20295<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Tentatively%20Ready">Tentatively Ready</a> status.</p>
20296<p><b>Discussion:</b></p>
20297<p>
20298In Table 73 -- Floating-point conversions, 22.4.2.2.2 [facet.num.put.virtuals], 
20299in
20300<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2914.pdf">N2914</a>,
20301we have the following entries: 
20302</p>
20303<table border="1">
20304<caption>Table 73 &#8212; Floating-point conversions</caption>
20305<tbody><tr>
20306<th>State</th> <th><tt>stdio</tt> equivalent</th>
20307</tr>
20308<tr>
20309<td><tt>floatfield == ios_base::fixed | ios_base::scientific &amp;&amp; !uppercase</tt></td>
20310<td align="center"><tt>%a</tt></td>
20311</tr>
20312
20313<tr>
20314<td><tt>floatfield == ios_base::fixed | ios_base::scientific</tt></td>
20315<td align="center"><tt>%A</tt></td>
20316</tr>
20317</tbody></table>
20318
20319<p>
20320These expressions are supposed to mean: 
20321</p>
20322
20323<blockquote><pre>floatfield == (ios_base::fixed | ios_base::scientific) &amp;&amp; !uppercase 
20324floatfield == (ios_base::fixed | ios_base::scientific) 
20325</pre></blockquote>
20326<p>
20327but technically parsed as: 
20328</p>
20329<blockquote><pre>((floatfield == ios_base::fixed) | ios_base::scientific) &amp;&amp; (!uppercase) 
20330((floatfield == ios_base::fixed) | ios_base::scientific) 
20331</pre></blockquote>
20332<p>
20333and should be corrected with additional parentheses, as shown above. 
20334</p>
20335
20336<p><i>[
203372009-10-28 Howard:
20338]</i></p>
20339
20340
20341<blockquote>
20342Moved to Tentatively Ready after 5 positive votes on c++std-lib.
20343</blockquote>
20344
20345
20346
20347<p><b>Proposed resolution:</b></p>
20348<p>
20349Change Table 83 &#8212; Floating-point conversions in  22.4.2.2.2 [facet.num.put.virtuals]:
20350</p>
20351
20352<table border="1">
20353<caption>Table 83 &#8212; Floating-point conversions</caption>
20354<tbody><tr>
20355<th>State</th> <th><tt>stdio</tt> equivalent</th>
20356</tr>
20357<tr>
20358<td><tt>floatfield == <ins>(</ins>ios_base::fixed | ios_base::scientific<ins>)</ins> &amp;&amp; !uppercase</tt></td>
20359<td align="center"><tt>%a</tt></td>
20360</tr>
20361
20362<tr>
20363<td><tt>floatfield == <ins>(</ins>ios_base::fixed | ios_base::scientific<ins>)</ins></tt></td>
20364<td align="center"><tt>%A</tt></td>
20365</tr>
20366</tbody></table>
20367
20368
20369
20370
20371
20372<hr>
20373<h3><a name="1153"></a>1153. Standard library needs review for constructors to be
20374explicit to avoid treatment as initializer-list constructor</h3>
20375<p><b>Section:</b> 17 [library], 30 [thread], D [depr] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
20376 <b>Submitter:</b> LWG <b>Opened:</b> 2009-06-28  <b>Last modified:</b> 2009-10-20</p>
20377<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#library">active issues</a> in [library].</p>
20378<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#library">issues</a> in [library].</p>
20379<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
20380<p><b>Discussion:</b></p>
20381
20382<p><b>Addresses DE 2</b></p>
20383
20384<p><b>Description</b></p>
20385        <p>Marking a constructor with <tt>explicit</tt> has semantics
20386        even for a constructor with zero or several parameters:
20387        Such a constructor cannot be used with list-initialization
20388        in a copy-initialization context, see 13.3.1.7 [over.match.list]. The
20389        standard library apparently has not been reviewed for
20390        marking non-single-parameter constructors as <tt>explicit</tt>.</p>
20391<p><b>Suggestion</b></p>
20392        <p>Consider marking zero-parameter and multi-parameter
20393        constructors <tt>explicit</tt> in classes that have at least one
20394        constructor marked <tt>explicit</tt> and that do not have an
20395        initializer-list constructor.</p>
20396
20397<p><b>Notes</b></p>
20398        <p>Robert Klarer to address this one.</p>
20399
20400<p><i>[
204012009 Santa Cruz:
20402]</i></p>
20403
20404
20405<blockquote>
20406Move to "Open". Robert Klarer has promised to provide wording.
20407</blockquote>
20408
20409
20410
20411<p><b>Proposed resolution:</b></p>
20412
20413
20414
20415
20416
20417<hr>
20418<h3><a name="1154"></a>1154. <tt>complex</tt> should accept integral types</h3>
20419<p><b>Section:</b> 26.4 [complex.numbers] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
20420 <b>Submitter:</b> LWG <b>Opened:</b> 2009-06-28  <b>Last modified:</b> 2009-10-26</p>
20421<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#complex.numbers">issues</a> in [complex.numbers].</p>
20422<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
20423<p><b>Discussion:</b></p>
20424
20425<p><b>Addresses FR 35</b></p>
20426
20427<p><b>Description</b></p>
20428        <p>Instantiations of the class
20429        template <tt>complex&lt;&gt;</tt> have to be allowed for integral
20430        types, to reflect existing practice and ISO standards
20431        (LIA-III).</p>
20432        
20433<p><b>Suggestion</b></p>
20434
20435<p><i>[
204362009-10-26 Proposed wording in
20437<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n3002.pdf">N3002</a>.
20438]</i></p>
20439
20440
20441
20442
20443<p><b>Proposed resolution:</b></p>
20444Adopt
20445<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n3002.pdf">N3002</a>.
20446
20447
20448
20449
20450
20451<hr>
20452<h3><a name="1156"></a>1156. Constraints on bitmask and enumeration types to be tightened</h3>
20453<p><b>Section:</b> 17.5.2.1.2 [enumerated.types], 17.5.2.1.3 [bitmask.types] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
20454 <b>Submitter:</b> LWG <b>Opened:</b> 2009-06-28  <b>Last modified:</b> 2009-10-27</p>
20455<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
20456<p><b>Discussion:</b></p>
20457
20458<p><b>Addresses UK 165</b></p>
20459
20460<p><b>Description</b></p>
20461        <p>Constraints on
20462        bitmask and enumeration types were supposed to be tightened
20463        up as part of the motivation for the <tt>constexpr</tt> feature -
20464        see paper
20465        <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2235.pdf">N2235</a>
20466        for details</p>
20467<p><b>Suggestion</b></p>
20468        <p>Adopt wording in line with the motivation
20469        described in
20470        <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2235.pdf">N2235</a></p>
20471<p><b>Notes</b></p>
20472        <p>Robert Klarer to review</p>
20473
20474<p><i>[
204752009 Santa Cruz:
20476]</i></p>
20477
20478
20479<blockquote>
20480Move to Open. Ping Robert Klarer to provide wording, using N2235 as
20481guidance.
20482</blockquote>
20483
20484
20485
20486<p><b>Proposed resolution:</b></p>
20487
20488
20489
20490
20491
20492<hr>
20493<h3><a name="1157"></a>1157. Local types can now instantiate templates</h3>
20494<p><b>Section:</b> 17.6.3.2.1 [namespace.std] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
20495 <b>Submitter:</b> LWG <b>Opened:</b> 2009-06-28  <b>Last modified:</b> 2009-10-21</p>
20496<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
20497<p><b>Discussion:</b></p>
20498
20499<p><b>Addresses UK 175</b></p>
20500
20501<p><b>Description</b></p>
20502        <p>Local types can
20503        now be used to instantiate templates, but don't have
20504        external linkage.</p>
20505<p><b>Suggestion</b></p>
20506        <p>Remove the reference to external linkage.</p>
20507
20508<p><b>Notes</b></p>
20509<p>We accept the proposed solution. Martin will draft an issue.</p>
20510
20511<p><i>[
205122009-07-28 Alisdair provided wording.
20513]</i></p>
20514
20515
20516<p><i>[
205172009-10 Santa Cruz:
20518]</i></p>
20519
20520
20521<blockquote>
20522Moved to Ready.
20523</blockquote>
20524
20525
20526
20527<p><b>Proposed resolution:</b></p>
20528<p>
2052917.6.3.2.1 [namespace.std]
20530</p>
20531<p>
20532Strike "of external linkage" in p1 and p2:
20533</p>
20534
20535<blockquote>
20536<p>
20537-1- The behavior of a C++ program is undefined if it adds declarations or
20538definitions to namespace <tt>std</tt> or to a namespace within namespace <tt>std</tt>
20539unless otherwise specified. A program may add a concept map for any
20540standard library concept or a template specialization for any standard
20541library template to namespace <tt>std</tt> only if the declaration depends on a
20542user-defined type <del>of external linkage</del> and the specialization meets the
20543standard library requirements for the original template and is not
20544explicitly prohibited.<sup>179</sup>
20545</p>
20546
20547<p>
20548-2- The behavior of a C++ program is undefined if it declares
20549</p>
20550<ul>
20551<li>
20552an explicit specialization of any member function of a standard library
20553class template, or
20554</li>
20555<li>
20556an explicit specialization of any member function template of a standard
20557library class or class template, or
20558</li>
20559<li>
20560an explicit or partial specialization of any member class template of a
20561standard library class or class template.
20562</li>
20563</ul>
20564<p>
20565A program may explicitly instantiate a template defined in the standard
20566library only if the declaration depends on the name of a user-defined
20567type <del>of external linkage</del> and the instantiation meets the standard
20568library requirements for the original template.
20569</p>
20570</blockquote>
20571
20572
20573
20574
20575
20576
20577<hr>
20578<h3><a name="1158"></a>1158. Encouragement to use monotonic clock</h3>
20579<p><b>Section:</b> 30.2.4 [thread.req.timing] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Tentatively Ready</a>
20580 <b>Submitter:</b> LWG <b>Opened:</b> 2009-06-28  <b>Last modified:</b> 2009-10-31</p>
20581<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Tentatively%20Ready">Tentatively Ready</a> status.</p>
20582<p><b>Discussion:</b></p>
20583
20584<p><b>Addresses UK 322, US 96</b></p>
20585
20586<p><b>Description</b></p>
20587        <p>Not all systems
20588        can provide a monotonic clock. How are they expected to
20589        treat a _for function?</p>
20590<p><b>Suggestion</b></p>
20591        <p>Add at least a note explaining the intent
20592        for systems that do not support a monotonic clock.</p>
20593
20594<p><b>Notes</b></p>
20595<p>Create an issue, together with UK 96. Note that the specification as is 
20596    already allows a non-monotonic clock due to the word &#8220;should&#8221; rather than 
20597    &#8220;shall&#8221;. If this wording is kept, a footnote should be added to make the 
20598    meaning clear.</p>
20599
20600<p><i>[ 2009-06-29 Beman provided a proposed resolution. ] </i></p>
20601
20602<p><i>[
206032009-10-31 Howard adds:
20604]</i></p>
20605
20606
20607<blockquote>
20608Set to Tentatively Ready after 5 positive votes on c++std-lib.
20609</blockquote>
20610
20611
20612
20613<p><b>Proposed resolution:</b></p>
20614
20615<p><i>Change Timing specifications 30.2.4 [thread.req.timing] as indicated:</i></p>
20616
20617<p>The member functions whose names end in <tt>_for</tt> take an argument that
20618specifies a relative time. Implementations
20619<del>should</del> <ins>are encouraged but not required to</ins> use a
20620monotonic clock to measure time for these functions.</p>
20621
20622
20623
20624
20625
20626
20627<hr>
20628<h3><a name="1159"></a>1159. Unclear spec for <tt>resource_deadlock_would_occur</tt></h3>
20629<p><b>Section:</b> 30.4.3.2.2 [thread.lock.unique.locking] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
20630 <b>Submitter:</b> LWG <b>Opened:</b> 2009-06-28  <b>Last modified:</b> 2009-07-04</p>
20631<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#thread.lock.unique.locking">active issues</a> in [thread.lock.unique.locking].</p>
20632<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#thread.lock.unique.locking">issues</a> in [thread.lock.unique.locking].</p>
20633<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
20634<p><b>Discussion:</b></p>
20635
20636<p><b>Addresses UK 327, UK 328</b></p>
20637
20638<p><b>UK 327 Description</b></p>
20639        <p>Not clear what
20640        the specification for error condition
20641        <tt>resource_deadlock_would_occur</tt> means. It is perfectly
20642        possible for this thread to own the mutex without setting
20643        owns to true on this specific lock object. It is also
20644        possible for lock operations to succeed even if the thread
20645        does own the mutex, if the mutex is recursive. Likewise, if
20646        the mutex is not recursive and the mutex has been locked
20647        externally, it is not always possible to know that this
20648        error condition should be raised, depending on the host
20649        operating system facilities. It is possible that 'i.e.' was
20650        supposed to be 'e.g.' and that suggests that recursive
20651        locks are not allowed. That makes sense, as the
20652        exposition-only member owns is boolean and not a integer to
20653        count recursive locks.</p>
20654        
20655<p><b>UK 327 Suggestion</b></p>
20656        <p>Add a precondition <tt>!owns</tt>. Change the 'i.e.'
20657        in the error condition to be 'e.g.' to allow for this
20658        condition to propogate deadlock detection by the host OS.</p>
20659<p><b>UK 327 Notes</b></p>
20660<p>Create an issue. Assigned to Lawrence Crowl. Note: not sure what try_lock 
20661    means for recursive locks when you are the owner. POSIX has language on 
20662    this, which should ideally be followed. Proposed fix is not quite right, for 
20663    example, try_lock should have different wording from lock.</p>
20664
20665<p><b>UK 328 Description</b></p>
20666
20667        <p>There is a missing precondition that <tt>owns</tt>
20668        is true, or an <tt>if(owns)</tt> test is missing from the effect
20669        clause</p>
20670<p><b>UK 328 Suggestion</b></p>
20671        <p>Add a
20672        precondition that <tt>owns == true</tt>. Add an error condition to
20673        detect a violation, rather than yield undefined behaviour.</p>
20674<p><b>UK 328 Notes</b></p>
20675<p>Handle in same issue as UK 327. Also uncertain that the proposed resolution 
20676    is the correct one.</p>
20677
20678    
20679
20680
20681<p><b>Proposed resolution:</b></p>
20682
20683
20684
20685
20686
20687<hr>
20688<h3><a name="1169"></a>1169. <tt>num_get</tt> not fully compatible with <tt>strto*</tt></h3>
20689<p><b>Section:</b> 22.4.2.1.2 [facet.num.get.virtuals] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
20690 <b>Submitter:</b> Cosmin Truta <b>Opened:</b> 2009-07-04  <b>Last modified:</b> 2009-07-07</p>
20691<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#facet.num.get.virtuals">active issues</a> in [facet.num.get.virtuals].</p>
20692<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#facet.num.get.virtuals">issues</a> in [facet.num.get.virtuals].</p>
20693<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
20694<p><b>Discussion:</b></p>
20695<p>
20696As specified in the latest draft,
20697<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2914.pdf">N2914</a>,
20698<code>num_get</code> is still not fully compatible with the following C
20699functions: <code>strtoul</code>, <code>strtoull</code>, 
20700<code>strtof</code> and
20701<code>strtod</code>.
20702</p>
20703<p>
20704In C, when conversion of a string to an unsigned integer type falls 
20705outside the
20706representable range, <code>strtoul</code> and <code>strtoull</code> return
20707<code>ULONG_MAX</code> and <code>ULLONG_MAX</code>, respectively, 
20708regardless
20709whether the input field represents a positive or a negative value.
20710On the other hand, the result of <code>num_get</code> conversion of 
20711negative
20712values to unsigned integer types is zero. This raises a compatibility 
20713issue.
20714</p>
20715<p>
20716Moreover, in C, when conversion of a string to a floating-point type falls
20717outside the representable range, <code>strtof</code>, <code>strtod</code> 
20718and
20719<code>strtold</code> return <code>�HUGE_VALF</code>,
20720<code>�HUGE_VAL</code> and <code>�HUGE_VALL</code>, respectively.
20721On the other hand, the result of <code>num_get</code> conversion of such
20722out-of-range floating-point values results in the most positive/negative
20723representable value.
20724Although many C library implementations do implement <code>HUGE_VAL</code>
20725(etc.) as the highest representable (which is, usually, the infinity), 
20726this
20727isn't required by the C standard. The C library specification makes no
20728statement regarding the value of <code>HUGE_VAL</code> and friends, which
20729potentially raises the same compatibility issue as in the above case of
20730unsigned integers.
20731In addition, neither C nor C++ define symbolic constants for the maximum
20732representable floating-point values (they only do so only for the maximum
20733representable <i>finite</i> floating-point values), which raises a 
20734usability
20735issue (it would be hard for the programmer to check the result of
20736<code>num_get</code> against overflow).
20737</p>
20738<p>
20739As such, we propose to adjust the specification of <code>num_get</code> to
20740closely follow the behavior of all of its underlying C functions.
20741</p>
20742
20743
20744<p><b>Proposed resolution:</b></p>
20745
20746<p>
20747Change 22.4.2.1.2 [facet.num.get.virtuals] as follows:
20748</p>
20749<blockquote>
20750<p>
20751<b>Stage 3:</b>
20752The sequence of <code>char</code>s accumulated in stage 2 (the field) is
20753converted to a numeric value by the rules of one of the functions declared in
20754the header <code>&lt;cstdlib&gt;</code>:
20755</p>
20756<ul>
20757<li>For a signed integer value, the function <code>strtoll</code>.</li>
20758<li>For an unsigned integer value, the function <code>strtoull</code>.</li>
20759<li><ins>For a <code>float</code> value, the function
20760    <code>strtof</code>.</ins></li>
20761<li><ins>For a <code>double</code> value, the function
20762    <code>strtod</code>.</ins></li>
20763<li>For a <del>floating-point</del> <ins><code>long double</code></ins>
20764    value, the function <code>strtold</code>.</li>
20765</ul>
20766<p>
20767The numeric value to be stored can be one of:
20768</p>
20769<ul>
20770<li>zero, if the conversion function fails to convert the entire field.
20771    <del><code>ios_base::failbit</code> is assigned to <code>err</code>.</del></li>
20772<li>the most positive <ins>(or negative)</ins> representable value, if
20773    the field <ins>to be converted to a signed integer type</ins> represents a
20774    value too large positive <ins>(or negative)</ins> to be represented in
20775    <code>val</code>.
20776    <del><code>ios_base::failbit</code> is assigned to <code>err</code>.</del></li>
20777<li><del>the most negative representable value or zero for an unsigned integer
20778    type, if the field represents a value too large negative to be represented
20779    in <code>val</code>.
20780    <code>ios_base::failbit</code> is assigned to <code>err</code>.</del></li>
20781<li><ins>the most positive representable value, if the field to be converted to
20782    an unsigned integer type represents a value that cannot be represented in
20783    <code>val</code>.</ins></li>
20784<li>the converted value, otherwise.</li>
20785</ul>
20786<p>
20787The resultant numeric value is stored in <code>val</code>.
20788<ins>If the conversion function fails to convert the entire field, or if the
20789field represents a value outside the range of representable values,
20790<code>ios_base::failbit</code> is assigned to <code>err</code>.</ins>
20791</p>
20792</blockquote>
20793
20794
20795
20796
20797
20798
20799<hr>
20800<h3><a name="1170"></a>1170. String <i>char-like types</i> no longer PODs</h3>
20801<p><b>Section:</b> 21.1 [strings.general] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
20802 <b>Submitter:</b> Beman Dawes <b>Opened:</b> 2009-06-22  <b>Last modified:</b> 2009-11-04</p>
20803<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
20804<p><b>Discussion:</b></p>
20805
20806<p><b>Addresses UK 218</b></p>
20807
20808<p>Prior to the introduction of constant expressions into the library, 
20809<tt>basic_string</tt> elements had to be POD types, and thus had to be both trivially 
20810copyable and standard-layout. This ensured that they could be memcpy'ed and 
20811would be compatible with other libraries and languages, particularly the C 
20812language and its library.</p>
20813<p>
20814<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2349.pdf">N2349</a>,
20815Constant Expressions in the Standard Library Revision 2, changed the 
20816requirement in 21/1 from "POD type" to "literal type". That change had the 
20817effect of removing the trivially copyable and standard-layout requirements from 
20818<tt>basic_string</tt> elements.</p>
20819<p>This means that <tt>basic_string</tt> elements no longer are guaranteed to be 
20820memcpy'able, and are no longer guaranteed to be standard-layout types:</p>
20821<blockquote>
20822  <p>3.9/p2 and 3.9/p3 both make it clear that a "trivially copyable type" is 
20823  required for memcpy to be guaranteed to work.</p>
20824  <p>Literal types (3.9p12) may have a non-trivial copy assignment operator, and 
20825  that violates the trivially copyable requirements given in 9/p 6, bullet item 
20826  2. </p>
20827  <p>Literal types (3.9p12) have no standard-layout requirement, either.</p>
20828</blockquote>
20829<p>This situation probably arose because the wording for "Constant Expressions 
20830in the Standard Library" was in process at the same time the C++ POD 
20831deconstruction wording was in process. </p>
20832<p>Since trivially copyable types meet the C++0x requirements for literal types, 
20833and thus work with constant expressions, it seems an easy fix to revert the 
20834<tt>basic_string</tt> element wording to its original state.</p>
20835
20836 <p><i>[
20837 2009-07-28 Alisdair adds:
20838 ]</i></p>
20839
20840 
20841<blockquote>
20842When looking for any resolution for this issue, consider the definition of
20843"character container type" in 17.3.4 [defns.character.container].  This
20844does require the character type to be a POD, and this term is used in a
20845number of places through clause 21 and 28. This suggests the PODness
20846constraint remains, but is much more subtle than before.  Meanwhile, I
20847suspect the change from POD type to literal type was intentional with
20848the assumption that trivially copyable types with
20849non-trivial-but-constexpr constructors should serve as well.  I don't
20850believe the current wording offers the right guarantees for either of
20851the above designs.
20852</blockquote>
20853
20854<p><i>[
208552009-11-04 Howard modifies proposed wording to disallow array types as
20856char-like types.
20857]</i></p>
20858
20859
20860
20861
20862<p><b>Proposed resolution:</b></p>
20863
20864<p><i>Change General 21.1 [strings.general] as indicated:</i></p>
20865<blockquote>
20866<p>This Clause describes components for manipulating sequences of any
20867<del>literal</del> <ins>non-array POD</ins> (3.9) type. In this Clause
20868such types are called <i>char-like types</i>, and objects of char-like
20869types are called <i>char-like objects</i> or simply
20870<i>characters</i>.</p>
20871</blockquote>
20872
20873
20874
20875
20876
20877
20878<hr>
20879<h3><a name="1171"></a>1171. duration types should be literal</h3>
20880<p><b>Section:</b> 20.9.3 [time.duration] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
20881 <b>Submitter:</b> Alisdair Meredith <b>Opened:</b> 2009-07-06  <b>Last modified:</b> 2009-10-31</p>
20882<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#time.duration">active issues</a> in [time.duration].</p>
20883<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#time.duration">issues</a> in [time.duration].</p>
20884<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
20885<p><b>Discussion:</b></p>
20886<p>
20887The <tt>duration</tt> types in 20.9.3 [time.duration] are exactly the sort of type
20888that should be "literal types" in the new standard.  Likewise,
20889arithmetic operations on <tt>duration</tt>s should be declared <tt>constexpr</tt>.
20890</p>
20891
20892<p><i>[
208932009-09-21 Daniel adds:
20894]</i></p>
20895
20896
20897<blockquote>
20898An alternative (and possibly preferable solution for potentially
20899heap-allocating big_int representation types) would be to ask the core
20900language to allow references to <tt>const</tt> literal types as feasible
20901arguments for <tt>constexpr</tt> functions.
20902</blockquote>
20903
20904<p><i>[
209052009-10-30 Alisdair adds:
20906]</i></p>
20907
20908
20909<blockquote>
20910<p>
20911I suggest this issue moves from New to Open.
20912</p>
20913
20914<p>
20915Half of this issue was dealt with in paper
20916<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2994.html">n2994</a>
20917on constexpr constructors.
20918</p>
20919
20920<p>
20921The other half (duration arithmetic) is on hold pending Core support for
20922<tt>const &amp;</tt> in <tt>constexpr</tt> functions.
20923</p>
20924
20925</blockquote>
20926
20927
20928
20929<p><b>Proposed resolution:</b></p>
20930<p>
20931Add <tt>constexpr</tt> to declaration of following functions and constructors:
20932</p>
20933<p>
20934p1 20.9 [time]
20935</p>
20936
20937<blockquote>
20938<p>
20939<b>Header <tt>&lt;chrono&gt;</tt> synopsis</b>
20940</p>
20941
20942<p><i>[Draughting note - observe switch to pass-by-value to support constexpr]</i></p>
20943
20944
20945<pre><i>// duration arithmetic</i>
20946template &lt;class Rep1, class Period1, class Rep2, class Period2&gt;
20947   typename common_type&lt;duration&lt;Rep1, Period1&gt;, duration&lt;Rep2, Period2&gt;&gt;::type
20948   <ins>constexpr</ins> operator+(<del>const</del> duration&lt;Rep1, Period1&gt;<del>&amp;</del> lhs, <del>const</del> duration&lt;Rep2, Period2&gt;<del>&amp;</del> rhs);
20949template &lt;class Rep1, class Period1, class Rep2, class Period2&gt;
20950   typename common_type&lt;duration&lt;Rep1, Period1&gt;, duration&lt;Rep2, Period2&gt;&gt;::type
20951   <ins>constexpr</ins> operator-(<del>const</del> duration&lt;Rep1, Period1&gt;<del>&amp;</del> lhs, <del>const</del> duration&lt;Rep2, Period2&gt;<del>&amp;</del> rhs);
20952template &lt;class Rep1, class Period, class Rep2&gt;
20953   duration&lt;typename common_type&lt;Rep1, Rep2&gt;::type, Period&gt;
20954   <ins>constexpr</ins> operator*(<del>const</del> duration&lt;Rep1, Period&gt;<del>&amp;</del> d, <del>const</del> Rep2<del>&amp;</del> s);
20955template &lt;class Rep1, class Period, class Rep2&gt;
20956   duration&lt;typename common_type&lt;Rep1, Rep2&gt;::type, Period&gt;
20957   <ins>constexpr</ins> operator*(<del>const</del> Rep1<del>&amp;</del> s, <del>const</del> duration&lt;Rep2, Period&gt;<del>&amp;</del> d);
20958template &lt;class Rep1, class Period, class Rep2&gt;
20959   duration&lt;typename common_type&lt;Rep1, Rep2&gt;::type, Period&gt;
20960   <ins>constexpr</ins> operator/(<del>const</del> duration&lt;Rep1, Period&gt;<del>&amp;</del> d, <del>const</del> Rep2<del>&amp;</del> s);
20961template &lt;class Rep1, class Period1, class Rep2, class Period2&gt;
20962   typename common_type&lt;Rep1, Rep2&gt;::type
20963   <ins>constexpr</ins> operator/(<del>const</del> duration&lt;Rep1, Period1&gt;<del>&amp;</del> lhs, <del>const</del> duration&lt;Rep2, Period2&gt;<del>&amp;</del> rhs);
20964
20965<i>// duration comparisons</i>
20966template &lt;class Rep1, class Period1, class Rep2, class Period2&gt;
20967   <ins>constexpr</ins> bool operator==(<del>const</del> duration&lt;Rep1, Period1&gt;<del>&amp;</del> lhs, <del>const</del> duration&lt;Rep2, Period2&gt;<del>&amp;</del> rhs);
20968template &lt;class Rep1, class Period1, class Rep2, class Period2&gt;
20969   <ins>constexpr</ins> bool operator!=(<del>const</del> duration&lt;Rep1, Period1&gt;<del>&amp;</del> lhs, <del>const</del> duration&lt;Rep2, Period2&gt;<del>&amp;</del> rhs);
20970template &lt;class Rep1, class Period1, class Rep2, class Period2&gt;
20971   <ins>constexpr</ins> bool operator&lt; (<del>const</del> duration&lt;Rep1, Period1&gt;<del>&amp;</del> lhs, <del>const</del> duration&lt;Rep2, Period2&gt;<del>&amp;</del> rhs);
20972template &lt;class Rep1, class Period1, class Rep2, class Period2&gt;
20973   <ins>constexpr</ins> bool operator&lt;=(<del>const</del> duration&lt;Rep1, Period1&gt;<del>&amp;</del> lhs, <del>const</del> duration&lt;Rep2, Period2&gt;<del>&amp;</del> rhs);
20974template &lt;class Rep1, class Period1, class Rep2, class Period2&gt;
20975   <ins>constexpr</ins> bool operator&gt; (<del>const</del> duration&lt;Rep1, Period1&gt;<del>&amp;</del> lhs, <del>const</del> duration&lt;Rep2, Period2&gt;<del>&amp;</del> rhs);
20976template &lt;class Rep1, class Period1, class Rep2, class Period2&gt;
20977   <ins>constexpr</ins> bool operator&gt;=(<del>const</del>  duration&lt;Rep1, Period1&gt;<del>&amp;</del> lhs, <del>const</del> duration&lt;Rep2, Period2&gt;<del>&amp;</del> rhs);
20978
20979<i>// duration_cast</i>
20980template &lt;class ToDuration, class Rep, class Period&gt;
20981   <ins>constexpr</ins> ToDuration duration_cast(<del>const</del> duration&lt;Rep, Period&gt;<del>&amp;</del> d);
20982</pre>
20983
20984<p>
20985<b>20.9.3 [time.duration]</b>
20986</p>
20987
20988<pre>template &lt;class Rep, class Period = ratio&lt;1&gt;&gt;
20989class duration {
20990  ....
20991public:
20992  <i>// 20.9.3.1, construct/copy/destroy:</i>
20993 <ins>constexpr</ins> duration() = default;
20994
20995 template &lt;class Rep2&gt;
20996   <ins>constexpr</ins> explicit duration(const Rep2&amp; r);
20997 template &lt;class Rep2, class Period2&gt;
20998   <ins>constexpr</ins> duration(const duration&lt;Rep2, Period2&gt;&amp; d);
20999
21000  <ins>constexpr</ins> duration(const duration&amp;) = default;
21001
21002  <i>// 20.9.3.2, observer:</i>
21003  <ins>constexpr</ins> rep count() const;
21004
21005  <i>// 20.9.3.3, arithmetic:</i>
21006  <ins>constexpr</ins> duration operator+() const;
21007  <ins>constexpr</ins> duration operator-() const;
21008  ...
21009
21010};
21011</pre>
21012</blockquote>
21013<p><i>[
21014Note - this edit already seems assumed by definition of the duration static members <tt>zero/min/max</tt>.
21015They cannot meaningfully be <tt>constexpr</tt> without this change.
21016]</i></p>
21017
21018
21019
21020
21021
21022
21023<hr>
21024<h3><a name="1173"></a>1173. "Equivalence" wishy-washiness</h3>
21025<p><b>Section:</b> 17 [library] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
21026 <b>Submitter:</b> David Abrahams <b>Opened:</b> 2009-07-14  <b>Last modified:</b> 2009-10-20</p>
21027<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#library">active issues</a> in [library].</p>
21028<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#library">issues</a> in [library].</p>
21029<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
21030<p><b>Discussion:</b></p>
21031<p>
21032Issue: The <tt>CopyConstructible</tt> requirements are wishy-washy.  It requires
21033that the copy is "equivalent" to the original, but "equivalent" is never
21034defined.
21035</p>
21036<p>
21037I believe this to be an example of a more general lack of rigor around
21038copy and assignment, although I haven't done the research to dig up all
21039the instances.
21040</p>
21041<p>
21042It's a problem because if you don't know what <tt>CopyConstructible</tt> means,
21043you also don't know what it means to copy a pair of <tt>CopyConstructible</tt>
21044types.  It doesn't prevent us from writing code, but it is a hole in our
21045ability to understand the meaning of copy.
21046</p>
21047<p>
21048Furthermore, I'm pretty sure that vector's copy constructor doesn't
21049require the elements to be <tt>EqualityComparable</tt>, so that table is actually
21050referring to some ill-defined notion of equivalence when it uses ==.
21051</p>
21052
21053<p><i>[
210542009 Santa Cruz:
21055]</i></p>
21056
21057
21058<blockquote>
21059Move to "Open". Dave is right that this is a big issue. Paper D2987
21060("Defining Move Special Member Functions", Bjarne Stroustrup and
21061Lawrence Crowl) touches on this but does not solve it. This issue is
21062discussed in Elements of Programming.
21063</blockquote>
21064
21065
21066
21067<p><b>Proposed resolution:</b></p>
21068
21069
21070
21071
21072
21073<hr>
21074<h3><a name="1175"></a>1175. <tt>unordered</tt> complexity</h3>
21075<p><b>Section:</b> 23.2.5 [unord.req] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
21076 <b>Submitter:</b> Pablo Halpern <b>Opened:</b> 2009-07-17  <b>Last modified:</b> 2009-07-19</p>
21077<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#unord.req">active issues</a> in [unord.req].</p>
21078<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#unord.req">issues</a> in [unord.req].</p>
21079<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
21080<p><b>Discussion:</b></p>
21081<p>
21082When I look at the <tt>unordered_*</tt> constructors, I think the complexity is poorly
21083described and does not follow the style of the rest of the standard.
21084</p>
21085
21086<p>
21087The complexity for the default constructor is specified as constant.
21088 Actually, it is proportional to <tt>n</tt>, but there are no invocations of
21089<tt>value_type</tt> constructors or other <tt>value_type</tt> operations.
21090</p>
21091
21092<p>
21093For the iterator-based constructor the complexity should be:
21094</p>
21095
21096<blockquote>
21097<i>Complexity:</i> exactly <tt>n</tt> calls to construct <tt>value_type</tt>
21098from <tt>InputIterator::value_type</tt> (where <tt>n = distance(f,l)</tt>).
21099The number of calls to <tt>key_equal::operator()</tt> is proportional to
21100<tt>n</tt> in the average case and <tt>n*n</tt> in the worst case.
21101</blockquote>
21102
21103
21104
21105<p><b>Proposed resolution:</b></p>
21106<p>
21107</p>
21108
21109
21110
21111
21112
21113<hr>
21114<h3><a name="1176"></a>1176. Make <tt>thread</tt> constructor non-variadic</h3>
21115<p><b>Section:</b> 30.3.1.2 [thread.thread.constr] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
21116 <b>Submitter:</b> Howard Hinnant <b>Opened:</b> 2009-07-18  <b>Last modified:</b> 2009-07-18</p>
21117<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#thread.thread.constr">active issues</a> in [thread.thread.constr].</p>
21118<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#thread.thread.constr">issues</a> in [thread.thread.constr].</p>
21119<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
21120<p><b>Discussion:</b></p>
21121<p>
21122The variadic <tt>thread</tt> constructor is causing controversy, e.g.
21123<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2901.pdf">N2901</a>.
21124This issue has been created as a placeholder for this course of action.
21125</p>
21126
21127<blockquote><pre>template &lt;class F<del>, class ...Args</del>&gt; thread(F&amp;&amp; f<del>, Args&amp;&amp;... args</del>);
21128</pre></blockquote>
21129
21130<p>
21131See <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#929">929</a> for wording which specifies an rvalue-ref signature but
21132with "decay behavior", but using variadics.
21133</p>
21134
21135
21136<p><b>Proposed resolution:</b></p>
21137<p>
21138</p>
21139
21140
21141
21142
21143
21144<hr>
21145<h3><a name="1177"></a>1177. Improve "diagnostic required" wording</h3>
21146<p><b>Section:</b> 20.9.3 [time.duration] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
21147 <b>Submitter:</b> Howard Hinnant <b>Opened:</b> 2009-07-18  <b>Last modified:</b> 2009-10-26</p>
21148<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#time.duration">active issues</a> in [time.duration].</p>
21149<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#time.duration">issues</a> in [time.duration].</p>
21150<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
21151<p><b>Discussion:</b></p>
21152<p>
21153"diagnostic required" has been used (by me) for code words meaning "use
21154<tt>enable_if</tt> to constrain templated functions.  This needs to be
21155improved by referring to the function signature as not participating in
21156the overload set, and moving this wording to a <i>Remarks</i> paragraph.
21157</p>
21158
21159<p><i>[
211602009-10 Santa Cruz:
21161]</i></p>
21162
21163
21164<blockquote>
21165Moved to Ready.
21166</blockquote>
21167
21168
21169
21170<p><b>Proposed resolution:</b></p>
21171<p><i>[
21172This proposed resolution addresses <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#947">947</a> and <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#974">974</a>. 
21173]</i></p>
21174
21175
21176<ol>
21177<li>
21178<p>
21179Change 20.9.3.1 [time.duration.cons]:
21180</p>
21181
21182<blockquote>
21183<pre>template &lt;class Rep2&gt; 
21184  explicit duration(const Rep2&amp; r);
21185</pre>
21186<blockquote>
21187<p>
21188<i><del>Requires:</del> <ins>Remarks:</ins></i>
21189<tt>Rep2</tt> shall be implicitly convertible to <tt>rep</tt> and
21190</p>
21191<ul>
21192<li>
21193<tt>treat_as_floating_point&lt;rep&gt;::value</tt> shall be <tt>true</tt> or
21194</li>
21195<li>
21196<tt>treat_as_floating_point&lt;Rep2&gt;::value</tt> shall be <tt>false</tt>.
21197</li>
21198</ul>
21199<p>
21200<del>Diagnostic required</del> <ins>If these constraints are not met, this
21201constructor shall not participate in overload resolution</ins>. [<i>Example:</i>
21202</p>
21203<blockquote><pre>duration&lt;int, milli&gt; d(3); // OK 
21204duration&lt;int, milli&gt; d(3.5); // error 
21205</pre></blockquote>
21206
21207<p>
21208&#8212; <i>end example</i>]
21209</p>
21210
21211<p>
21212<i>Effects:</i> Constructs an object of type <tt>duration</tt>.
21213</p>
21214
21215<p>
21216<i>Postcondition:</i> <tt>count() == static_cast&lt;rep&gt;(r)</tt>.
21217</p>
21218
21219</blockquote>
21220
21221<pre>template &lt;class Rep2, class Period2&gt;
21222  duration(const duration&lt;Rep2, Period2&gt;&amp; d);
21223</pre>
21224<blockquote>
21225<p>
21226<i><del>Requires:</del> <ins>Remarks:</ins></i> <tt>treat_as_floating_point&lt;rep&gt;::value</tt> shall be <tt>true</tt> or
21227<tt>ratio_divide&lt;Period2, period&gt;::type::den</tt> shall be 1<del>. Diagnostic
21228required</del><ins>, else this constructor shall not participate in overload
21229resolution</ins>. [<i>Note:</i> This requirement prevents implicit truncation error
21230when converting between integral-based duration types. Such a
21231construction could easily lead to confusion about the value of the
21232duration. &#8212; <i>end note</i>] [<i>Example:</i>
21233</p>
21234
21235<blockquote><pre>duration&lt;int, milli&gt; ms(3); 
21236duration&lt;int, micro&gt; us = ms; // OK 
21237duration&lt;int, milli&gt; ms2 = us; // error 
21238</pre></blockquote>
21239
21240<p>
21241&#8212; <i>end example</i>]
21242</p>
21243
21244<p>
21245<i>Effects:</i> Constructs an object of type <tt>duration</tt>, constructing
21246<tt>rep_</tt> from
21247<tt>duration_cast&lt;duration&gt;(d).count()</tt>.
21248</p>
21249
21250</blockquote>
21251
21252
21253</blockquote>
21254</li>
21255
21256<li>
21257<p>
21258Change the following paragraphs in 20.9.3.5 [time.duration.nonmember]:
21259</p>
21260
21261<blockquote>
21262<pre>template &lt;class Rep1, class Period, class Rep2&gt; 
21263  duration&lt;typename common_type&lt;Rep1, Rep2&gt;::type, Period&gt; 
21264  operator*(const duration&lt;Rep1, Period&gt;&amp; d, const Rep2&amp; s);
21265</pre>
21266<blockquote>
21267<i><del>Requires</del> <ins>Remarks</ins>:</i> <tt>Rep2</tt> shall be implicitly convertible to
21268<tt>CR(Rep1, Rep2)</tt><ins>, else this signature shall not participate in
21269overload resolution</ins>. <del>Diagnostic required.</del>
21270</blockquote>
21271
21272<pre>template &lt;class Rep1, class Period, class Rep2&gt; 
21273  duration&lt;typename common_type&lt;Rep1, Rep2&gt;::type, Period&gt; 
21274  operator*(const Rep1&amp; s, const duration&lt;Rep2, Period&gt;&amp; d);
21275</pre>
21276<blockquote>
21277<i><del>Requires</del> <ins>Remarks</ins>:</i> <tt>Rep1</tt> shall be implicitly convertible to
21278<tt>CR(Rep1, Rep2)</tt><ins>, else this signature shall not participate in
21279overload resolution</ins>. <del>Diagnostic required.</del>
21280</blockquote>
21281
21282<pre>template &lt;class Rep1, class Period, class Rep2&gt; 
21283  duration&lt;typename common_type&lt;Rep1, Rep2&gt;::type, Period&gt; 
21284  operator/(const duration&lt;Rep1, Period&gt;&amp; d, const Rep2&amp; s);
21285</pre>
21286<blockquote>
21287<i><del>Requires</del> <ins>Remarks</ins>:</i> <tt>Rep2</tt> shall be implicitly convertible to
21288<tt>CR(Rep1, Rep2)</tt> and <tt>Rep2</tt> shall not be an instantiation of
21289<tt>duration</tt><ins>, else this signature shall not participate in
21290overload resolution</ins>. <del>Diagnostic required.</del>
21291</blockquote>
21292
21293<pre>template &lt;class Rep1, class Period, class Rep2&gt; 
21294  duration&lt;typename common_type&lt;Rep1, Rep2&gt;::type, Period&gt; 
21295  operator%(const duration&lt;Rep1, Period&gt;&amp; d, const Rep2&amp; s);
21296</pre>
21297<blockquote>
21298<i><del>Requires</del> <ins>Remarks</ins>:</i> <tt>Rep2</tt> shall be implicitly convertible to
21299<tt>CR(Rep1, Rep2)</tt> and <tt>Rep2</tt> shall not be an instantiation of
21300<tt>duration</tt><ins>, else this signature shall not participate in
21301overload resolution</ins>. <del>Diagnostic required.</del>
21302</blockquote>
21303
21304</blockquote>
21305</li>
21306
21307<li>
21308<p>
21309Change the following paragraphs in 20.9.3.7 [time.duration.cast]:
21310</p>
21311
21312<blockquote><pre>template &lt;class ToDuration, class Rep, class Period&gt; 
21313  ToDuration duration_cast(const duration&lt;Rep, Period&gt;&amp; d);
21314</pre>
21315
21316<blockquote>
21317<i><del>Requires</del> <ins>Remarks</ins>:</i> <tt>ToDuration</tt> shall be an instantiation of
21318<tt>duration</tt><ins>, else this signature shall not participate in
21319overload resolution</ins>. <del>Diagnostic required.</del>
21320</blockquote>
21321</blockquote>
21322</li>
21323
21324<li>
21325<p>
21326Change the following paragraphs in 20.9.4.7 [time.point.cast]:
21327</p>
21328
21329<blockquote><pre>template &lt;class ToDuration, class Clock, class Duration&gt; 
21330  time_point&lt;Clock, ToDuration&gt; time_point_cast(const time_point&lt;Clock, Duration&gt;&amp; t);
21331</pre>
21332
21333<blockquote>
21334<i><del>Requires</del> <ins>Remarks</ins>:</i> <tt>ToDuration</tt> shall be an instantiation of
21335<tt>duration</tt><ins>, else this signature shall not participate in
21336overload resolution</ins>. <del>Diagnostic required.</del>
21337</blockquote>
21338</blockquote>
21339</li>
21340</ol>
21341
21342
21343
21344
21345
21346
21347<hr>
21348<h3><a name="1180"></a>1180. Missing string_type member typedef in class <tt>sub_match</tt></h3>
21349<p><b>Section:</b> 28.9.1 [re.submatch.members] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
21350 <b>Submitter:</b> Daniel Kr�gler <b>Opened:</b> 2009-07-25  <b>Last modified:</b> 2009-07-26</p>
21351<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
21352<p><b>Discussion:</b></p>
21353<p>
21354The definition of class template <tt>sub_match</tt> is strongly dependent
21355on the type <tt>basic_string&lt;value_type&gt;</tt>, both in interface and effects,
21356but does not provide a corresponding typedef <tt>string_type</tt>, as e.g.
21357class <tt>match_results</tt> does, which looks like an oversight to me that
21358should be fixed.
21359</p>
21360
21361
21362<p><b>Proposed resolution:</b></p>
21363
21364<ol>
21365<li>
21366<p>
21367In the class template <tt>sub_match</tt> synopsis 28.9 [re.submatch]/1
21368change as indicated:
21369</p>
21370
21371<blockquote><pre>template &lt;class BidirectionalIterator&gt;
21372class sub_match : public std::pair&lt;BidirectionalIterator, BidirectionalIterator&gt; {
21373public:
21374  typedef typename iterator_traits&lt;BidirectionalIterator&gt;::value_type value_type;
21375  typedef typename iterator_traits&lt;BidirectionalIterator&gt;::difference_type difference_type;
21376  typedef BidirectionalIterator iterator;
21377  <ins>typedef basic_string&lt;value_type&gt; string_type;</ins>
21378
21379  bool matched;
21380
21381  difference_type length() const;
21382  operator <del>basic_string&lt;value_type&gt;</del><ins>string_type</ins>() const;
21383  <del>basic_string&lt;value_type&gt;</del><ins>string_type</ins> str() const;
21384  int compare(const sub_match&amp; s) const;
21385  int compare(const <del>basic_string&lt;value_type&gt;</del><ins>string_type</ins>&amp; s) const;
21386  int compare(const value_type* s) const;
21387};
21388</pre></blockquote>
21389</li>
21390
21391<li>
21392<p>
21393In 28.9.1 [re.submatch.members]/2 change as indicated:
21394</p>
21395
21396<blockquote><pre>operator <del>basic_string&lt;value_type&gt;</del><ins>string_type</ins>() const;
21397</pre>
21398
21399<blockquote>
21400<i>Returns:</i> <tt>matched ? <del>basic_string&lt;value_type&gt;</del>
21401<ins>string_type</ins>(first, second) : <del>basic_string&lt;value_type&gt;</del>
21402<ins>string_type</ins>()</tt>.
21403</blockquote>
21404</blockquote>
21405</li>
21406
21407<li>
21408<p>
21409In 28.9.1 [re.submatch.members]/3 change as indicated:
21410</p>
21411
21412<blockquote><pre><del>basic_string&lt;value_type&gt;</del><ins>string_type</ins> str() const;
21413</pre>
21414
21415<blockquote>
21416<i>Returns:</i> <tt>matched ? <del>basic_string&lt;value_type&gt;</del>
21417<ins>string_type</ins>(first, second) : <del>basic_string&lt;value_type&gt;</del>
21418<ins>string_type</ins>()</tt>.
21419</blockquote>
21420</blockquote>
21421</li>
21422</ol>
21423
21424
21425
21426
21427
21428
21429<hr>
21430<h3><a name="1181"></a>1181. Invalid <tt>sub_match</tt> comparison operators</h3>
21431<p><b>Section:</b> 28.9.2 [re.submatch.op] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
21432 <b>Submitter:</b> Daniel Kr�gler <b>Opened:</b> 2009-07-25  <b>Last modified:</b> 2009-07-28</p>
21433<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#re.submatch.op">issues</a> in [re.submatch.op].</p>
21434<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
21435<p><b>Discussion:</b></p>
21436<p>
21437Several heterogeneous comparison operators of class template
21438<tt>sub_match</tt> are specified by return clauses that are not valid
21439in general. E.g. 28.9.2 [re.submatch.op]/7:
21440</p>
21441
21442<blockquote><pre>template &lt;class BiIter, class ST, class SA&gt;
21443bool operator==(
21444  const basic_string&lt;
21445    typename iterator_traits&lt;BiIter&gt;::value_type, ST, SA&gt;&amp; lhs,
21446  const sub_match&lt;BiIter&gt;&amp; rhs);
21447</pre>
21448<blockquote>
21449<i>Returns:</i> <tt>lhs == rhs.str()</tt>.
21450</blockquote>
21451</blockquote>
21452
21453<p>
21454The returns clause would be ill-formed for all cases where
21455<tt>ST != std::char_traits&lt;iterator_traits&lt;BiIter&gt;::value_type&gt;</tt>
21456or <tt>SA != std::allocator&lt;iterator_traits&lt;BiIter&gt;::value_type&gt;</tt>.
21457</p>
21458<p>
21459The generic character of the comparison was intended, so
21460there are basically two approaches to fix the problem: The
21461first one would define the semantics of the comparison
21462using the traits class <tt>ST</tt> (The semantic of <tt>basic_string::compare</tt>
21463is defined in terms of the compare function of the corresponding
21464traits class), the second one would define the semantics of the
21465comparison using the traits class
21466</p>
21467
21468<blockquote><pre>std::char_traits&lt;iterator_traits&lt;BiIter&gt;::value_type&gt;
21469</pre></blockquote>
21470
21471<p>
21472which is essentially identical to
21473</p>
21474
21475<blockquote><pre>std::char_traits&lt;sub_match&lt;BiIter&gt;::value_type&gt;
21476</pre></blockquote>
21477
21478<p>
21479I suggest to follow the second approach, because
21480this emphasizes the central role of the <tt>sub_match</tt>
21481object as part of the comparison and would also
21482make sure that a <tt>sub_match</tt> comparison using some
21483<tt>basic_string&lt;char_t, ..&gt;</tt> always is equivalent to
21484a corresponding comparison with a string literal
21485because of the existence of further overloads (beginning
21486from 28.9.2 [re.submatch.op]/19). If users really want to
21487take advantage of their own <tt>traits::compare</tt>, they can
21488simply write a corresponding compare function that
21489does so.
21490</p>
21491
21492
21493<p><b>Proposed resolution:</b></p>
21494<ol>
21495<li>
21496<p>
21497In 28.9.2 [re.submatch.op] change as indicated:
21498</p>
21499
21500<ol type="a">
21501<li>
21502
21503<p>
21504If <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1180">1180</a> is accepted:
21505</p>
21506
21507<blockquote>
21508<pre>template &lt;class BiIter, class ST, class SA&gt;
21509  bool operator==(
21510    const basic_string&lt;
21511      typename iterator_traits&lt;BiIter&gt;::value_type, ST, SA&gt;&amp; lhs,
21512    const sub_match&lt;BiIter&gt;&amp; rhs);
21513</pre>
21514<blockquote>
215157 <i>Returns:</i> <tt><del>lhs</del><ins>typename
21516sub_match&lt;BiIter&gt;::string_type(lhs.begin(), lhs.end())</ins> ==
21517rhs.str()</tt>.
21518</blockquote>
21519
21520<pre>template &lt;class BiIter, class ST, class SA&gt;
21521  bool operator!=(
21522    const basic_string&lt;
21523      typename iterator_traits&lt;BiIter&gt;::value_type, ST, SA&gt;&amp; lhs,
21524    const sub_match&lt;BiIter&gt;&amp; rhs);
21525</pre>
21526
21527<blockquote>
215288 <i>Returns:</i> <tt><del>lhs</del><ins>typename
21529sub_match&lt;BiIter&gt;::string_type(lhs.begin(), lhs.end())</ins> !=
21530rhs.str()</tt>.
21531</blockquote>
21532
21533<pre>template &lt;class BiIter, class ST, class SA&gt;
21534  bool operator&lt;(
21535    const basic_string&lt;
21536      typename iterator_traits&lt;BiIter&gt;::value_type, ST, SA&gt;&amp; lhs,
21537    const sub_match&lt;BiIter&gt;&amp; rhs);
21538</pre>
21539
21540<blockquote>
215419 <i>Returns:</i> <tt><del>lhs</del><ins>typename
21542sub_match&lt;BiIter&gt;::string_type(lhs.begin(), lhs.end())</ins> &lt;
21543rhs.str()</tt>.
21544</blockquote>
21545
21546<pre>template &lt;class BiIter, class ST, class SA&gt;
21547  bool operator&gt;(
21548    const basic_string&lt;
21549      typename iterator_traits&lt;BiIter&gt;::value_type, ST, SA&gt;&amp; lhs,
21550    const sub_match&lt;BiIter&gt;&amp; rhs);
21551</pre>
21552
21553<blockquote>
2155410 <i>Returns:</i> <tt><del>lhs</del><ins>typename
21555sub_match&lt;BiIter&gt;::string_type(lhs.begin(), lhs.end())</ins> &gt;
21556rhs.str()</tt>.
21557</blockquote>
21558
21559<pre>template &lt;class BiIter, class ST, class SA&gt;
21560  bool operator&gt;=(
21561    const basic_string&lt;
21562      typename iterator_traits&lt;BiIter&gt;::value_type, ST, SA&gt;&amp; lhs,
21563    const sub_match&lt;BiIter&gt;&amp; rhs);
21564</pre>
21565
21566<blockquote>
2156711 <i>Returns:</i> <tt><del>lhs</del><ins>typename
21568sub_match&lt;BiIter&gt;::string_type(lhs.begin(), lhs.end())</ins> &gt;=
21569rhs.str()</tt>.
21570</blockquote>
21571
21572<pre>template &lt;class BiIter, class ST, class SA&gt;
21573  bool operator&lt;=(
21574    const basic_string&lt;
21575      typename iterator_traits&lt;BiIter&gt;::value_type, ST, SA&gt;&amp; lhs,
21576    const sub_match&lt;BiIter&gt;&amp; rhs);
21577</pre>
21578
21579<blockquote>
2158012 <i>Returns:</i> <tt><del>lhs</del><ins>typename
21581sub_match&lt;BiIter&gt;::string_type(lhs.begin(), lhs.end())</ins> &lt;=
21582rhs.str()</tt>.
21583</blockquote>
21584
21585<pre>template &lt;class BiIter, class ST, class SA&gt;
21586  bool operator==(const sub_match&lt;BiIter&gt;&amp; lhs,
21587    const basic_string&lt;
21588      typename iterator_traits&lt;BiIter&gt;::value_type, ST, SA&gt;&amp; rhs);
21589</pre>
21590
21591<blockquote>
2159213 <i>Returns:</i> <tt>lhs.str() == <del>rhs</del><ins>typename
21593sub_match&lt;BiIter&gt;::string_type(rhs.begin(), rhs.end())</ins></tt>.
21594</blockquote>
21595
21596<pre>template &lt;class BiIter, class ST, class SA&gt;
21597  bool operator!=(const sub_match&lt;BiIter&gt;&amp; lhs,
21598    const basic_string&lt;
21599      typename iterator_traits&lt;BiIter&gt;::value_type, ST, SA&gt;&amp; rhs);
21600</pre>
21601
21602<blockquote>
2160314 <i>Returns:</i> <tt>lhs.str() != <del>rhs</del><ins>typename
21604sub_match&lt;BiIter&gt;::string_type(rhs.begin(), rhs.end())</ins></tt>.
21605</blockquote>
21606
21607<pre>template &lt;class BiIter, class ST, class SA&gt;
21608  bool operator&lt;(const sub_match&lt;BiIter&gt;&amp; lhs,
21609    const basic_string&lt;
21610      typename iterator_traits&lt;BiIter&gt;::value_type, ST, SA&gt;&amp; rhs);
21611</pre>
21612
21613<blockquote>
2161415 <i>Returns:</i> <tt>lhs.str() &lt; <del>rhs</del><ins>typename
21615sub_match&lt;BiIter&gt;::string_type(rhs.begin(), rhs.end())</ins></tt>.
21616</blockquote>
21617
21618<pre>template &lt;class BiIter, class ST, class SA&gt;
21619  bool operator&gt;(const sub_match&lt;BiIter&gt;&amp; lhs,
21620    const basic_string&lt;
21621      typename iterator_traits&lt;BiIter&gt;::value_type, ST, SA&gt;&amp; rhs);
21622</pre>
21623
21624<blockquote>
2162516 <i>Returns:</i> <tt>lhs.str() &gt; <del>rhs</del><ins>typename
21626sub_match&lt;BiIter&gt;::string_type(rhs.begin(), rhs.end())</ins></tt>.
21627</blockquote>
21628
21629<pre>template &lt;class BiIter, class ST, class SA&gt;
21630  bool operator&gt;=(const sub_match&lt;BiIter&gt;&amp; lhs,
21631    const basic_string&lt;
21632      typename iterator_traits&lt;BiIter&gt;::value_type, ST, SA&gt;&amp; rhs);
21633</pre>
21634
21635<blockquote>
2163617 <i>Returns:</i> <tt>lhs.str() &gt;= <del>rhs</del><ins>typename
21637sub_match&lt;BiIter&gt;::string_type(rhs.begin(), rhs.end())</ins></tt>.
21638</blockquote>
21639
21640<pre>template &lt;class BiIter, class ST, class SA&gt;
21641  bool operator&lt;=(const sub_match&lt;BiIter&gt;&amp; lhs,
21642    const basic_string&lt;
21643      typename iterator_traits&lt;BiIter&gt;::value_type, ST, SA&gt;&amp; rhs);
21644</pre>
21645
21646<blockquote>
2164718 <i>Returns:</i> <tt>lhs.str() &lt;= <del>rhs</del><ins>typename
21648sub_match&lt;BiIter&gt;::string_type(rhs.begin(), rhs.end())</ins></tt>.
21649</blockquote>
21650</blockquote>
21651
21652</li>
21653
21654<li>
21655
21656<p>
21657If <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1180">1180</a> is <em>not</em> accepted:
21658</p>
21659
21660<blockquote>
21661<pre>template &lt;class BiIter, class ST, class SA&gt;
21662  bool operator==(
21663    const basic_string&lt;
21664      typename iterator_traits&lt;BiIter&gt;::value_type, ST, SA&gt;&amp; lhs,
21665    const sub_match&lt;BiIter&gt;&amp; rhs);
21666</pre>
21667<blockquote>
216687 <i>Returns:</i> <tt><del>lhs</del><ins>basic_string&lt;typename
21669sub_match&lt;BiIter&gt;::value_type&gt;(lhs.begin(), lhs.end())</ins> ==
21670rhs.str()</tt>.
21671</blockquote>
21672
21673<pre>template &lt;class BiIter, class ST, class SA&gt;
21674  bool operator!=(
21675    const basic_string&lt;
21676      typename iterator_traits&lt;BiIter&gt;::value_type, ST, SA&gt;&amp; lhs,
21677    const sub_match&lt;BiIter&gt;&amp; rhs);
21678</pre>
21679
21680<blockquote>
216818 <i>Returns:</i> <tt><del>lhs</del><ins>basic_string&lt;typename
21682sub_match&lt;BiIter&gt;::value_type&gt;(lhs.begin(), lhs.end())</ins> !=
21683rhs.str()</tt>.
21684</blockquote>
21685
21686<pre>template &lt;class BiIter, class ST, class SA&gt;
21687  bool operator&lt;(
21688    const basic_string&lt;
21689      typename iterator_traits&lt;BiIter&gt;::value_type, ST, SA&gt;&amp; lhs,
21690    const sub_match&lt;BiIter&gt;&amp; rhs);
21691</pre>
21692
21693<blockquote>
216949 <i>Returns:</i> <tt><del>lhs</del><ins>basic_string&lt;typename
21695sub_match&lt;BiIter&gt;::value_type&gt;(lhs.begin(), lhs.end())</ins> &lt;
21696rhs.str()</tt>.
21697</blockquote>
21698
21699<pre>template &lt;class BiIter, class ST, class SA&gt;
21700  bool operator&gt;(
21701    const basic_string&lt;
21702      typename iterator_traits&lt;BiIter&gt;::value_type, ST, SA&gt;&amp; lhs,
21703    const sub_match&lt;BiIter&gt;&amp; rhs);
21704</pre>
21705
21706<blockquote>
2170710 <i>Returns:</i> <tt><del>lhs</del><ins>basic_string&lt;typename
21708sub_match&lt;BiIter&gt;::value_type&gt;(lhs.begin(), lhs.end())</ins> &gt;
21709rhs.str()</tt>.
21710</blockquote>
21711
21712<pre>template &lt;class BiIter, class ST, class SA&gt;
21713  bool operator&gt;=(
21714    const basic_string&lt;
21715      typename iterator_traits&lt;BiIter&gt;::value_type, ST, SA&gt;&amp; lhs,
21716    const sub_match&lt;BiIter&gt;&amp; rhs);
21717</pre>
21718
21719<blockquote>
2172011 <i>Returns:</i> <tt><del>lhs</del><ins>basic_string&lt;typename
21721sub_match&lt;BiIter&gt;::value_type&gt;(lhs.begin(), lhs.end())</ins> &gt;=
21722rhs.str()</tt>.
21723</blockquote>
21724
21725<pre>template &lt;class BiIter, class ST, class SA&gt;
21726  bool operator&lt;=(
21727    const basic_string&lt;
21728      typename iterator_traits&lt;BiIter&gt;::value_type, ST, SA&gt;&amp; lhs,
21729    const sub_match&lt;BiIter&gt;&amp; rhs);
21730</pre>
21731
21732<blockquote>
2173312 <i>Returns:</i> <tt><del>lhs</del><ins>basic_string&lt;typename
21734sub_match&lt;BiIter&gt;::value_type&gt;(lhs.begin(), lhs.end())</ins> &lt;=
21735rhs.str()</tt>.
21736</blockquote>
21737
21738<pre>template &lt;class BiIter, class ST, class SA&gt;
21739  bool operator==(const sub_match&lt;BiIter&gt;&amp; lhs,
21740    const basic_string&lt;
21741      typename iterator_traits&lt;BiIter&gt;::value_type, ST, SA&gt;&amp; rhs);
21742</pre>
21743
21744<blockquote>
2174513 <i>Returns:</i> <tt>lhs.str() == <del>rhs</del><ins>basic_string&lt;typename
21746sub_match&lt;BiIter&gt;::value_type&gt;(rhs.begin(), rhs.end())</ins></tt>.
21747</blockquote>
21748
21749<pre>template &lt;class BiIter, class ST, class SA&gt;
21750  bool operator!=(const sub_match&lt;BiIter&gt;&amp; lhs,
21751    const basic_string&lt;
21752      typename iterator_traits&lt;BiIter&gt;::value_type, ST, SA&gt;&amp; rhs);
21753</pre>
21754
21755<blockquote>
2175614 <i>Returns:</i> <tt>lhs.str() != <del>rhs</del><ins>basic_string&lt;typename
21757sub_match&lt;BiIter&gt;::value_type&gt;(rhs.begin(), rhs.end())</ins></tt>.
21758</blockquote>
21759
21760<pre>template &lt;class BiIter, class ST, class SA&gt;
21761  bool operator&lt;(const sub_match&lt;BiIter&gt;&amp; lhs,
21762    const basic_string&lt;
21763      typename iterator_traits&lt;BiIter&gt;::value_type, ST, SA&gt;&amp; rhs);
21764</pre>
21765
21766<blockquote>
2176715 <i>Returns:</i> <tt>lhs.str() &lt; <del>rhs</del><ins>basic_string&lt;typename
21768sub_match&lt;BiIter&gt;::value_type&gt;(rhs.begin(), rhs.end())</ins></tt>.
21769</blockquote>
21770
21771<pre>template &lt;class BiIter, class ST, class SA&gt;
21772  bool operator&gt;(const sub_match&lt;BiIter&gt;&amp; lhs,
21773    const basic_string&lt;
21774      typename iterator_traits&lt;BiIter&gt;::value_type, ST, SA&gt;&amp; rhs);
21775</pre>
21776
21777<blockquote>
2177816 <i>Returns:</i> <tt>lhs.str() &gt; <del>rhs</del><ins>basic_string&lt;typename
21779sub_match&lt;BiIter&gt;::value_type&gt;(rhs.begin(), rhs.end())</ins></tt>.
21780</blockquote>
21781
21782<pre>template &lt;class BiIter, class ST, class SA&gt;
21783  bool operator&gt;=(const sub_match&lt;BiIter&gt;&amp; lhs,
21784    const basic_string&lt;
21785      typename iterator_traits&lt;BiIter&gt;::value_type, ST, SA&gt;&amp; rhs);
21786</pre>
21787
21788<blockquote>
2178917 <i>Returns:</i> <tt>lhs.str() &gt;= <del>rhs</del><ins>basic_string&lt;typename
21790sub_match&lt;BiIter&gt;::value_type&gt;(rhs.begin(), rhs.end())</ins></tt>.
21791</blockquote>
21792
21793<pre>template &lt;class BiIter, class ST, class SA&gt;
21794  bool operator&lt;=(const sub_match&lt;BiIter&gt;&amp; lhs,
21795    const basic_string&lt;
21796      typename iterator_traits&lt;BiIter&gt;::value_type, ST, SA&gt;&amp; rhs);
21797</pre>
21798
21799<blockquote>
2180018 <i>Returns:</i> <tt>lhs.str() &lt;= <del>rhs</del><ins>basic_string&lt;typename
21801sub_match&lt;BiIter&gt;::value_type&gt;(rhs.begin(), rhs.end())</ins></tt>.
21802</blockquote>
21803</blockquote>
21804
21805</li>
21806
21807</ol>
21808
21809</li>
21810</ol>
21811
21812
21813
21814
21815
21816<hr>
21817<h3><a name="1182"></a>1182. Unfortunate hash dependencies</h3>
21818<p><b>Section:</b> 20.7.16 [unord.hash] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
21819 <b>Submitter:</b> Alisdair Meredith <b>Opened:</b> 2009-07-28  <b>Last modified:</b> 2009-09-21</p>
21820<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#unord.hash">active issues</a> in [unord.hash].</p>
21821<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#unord.hash">issues</a> in [unord.hash].</p>
21822<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
21823<p><b>Discussion:</b></p>
21824<p>
21825The implied library dependencies created by spelling out all the <tt>hash</tt>
21826template specializations in the <tt>&lt;functional&gt;</tt> synopsis are unfortunate. 
21827The potential coupling is greatly reduced if the <tt>hash</tt> specialization is
21828declared in the appropriate header for each library type, as it is much
21829simpler to forward declare the primary template and provide a single
21830specialization than it is to implement a <tt>hash</tt> function for a <tt>string</tt> or
21831<tt>vector</tt> without providing a definition for the whole <tt>string/vector</tt>
21832template in order to access the necessary bits.
21833</p>
21834
21835<p>
21836Note that the proposed resolution purely involves moving the
21837declarations of a few specializations, it specifically does not make any
21838changes to 20.7.16 [unord.hash].
21839</p>
21840
21841<p><i>[
218422009-09-15 Daniel adds:
21843]</i></p>
21844
21845
21846<blockquote>
21847</blockquote>
21848<p>
21849I suggest to add to the current existing
21850proposed resolution the following items.
21851</p>
21852
21853<ul>
21854<li>
21855<p>
21856Add to the very first strike-list of the currently suggested resolution
21857the following lines:
21858</p>
21859
21860<blockquote><pre><del>template &lt;&gt; struct hash&lt;std::error_code&gt;;</del>
21861<del>template &lt;&gt; struct hash&lt;std::thread::id&gt;;</del>
21862</pre></blockquote>
21863</li>
21864
21865<li>
21866<p>
21867Add the following declarations to 19.5 [syserr], header
21868<tt>&lt;system_error&gt;</tt> synopsis after // 19.5.4:
21869</p>
21870
21871<blockquote><pre><ins>
21872// 19.5.x hash support
21873template &lt;class T&gt; struct hash;
21874template &lt;&gt; struct hash&lt;error_code&gt;;
21875</ins>
21876</pre></blockquote>
21877</li>
21878
21879<li>
21880<p>
21881Add a new clause 19.5.X (probably after 19.5.4):
21882</p>
21883
21884<blockquote>
21885<p><ins>
2188619.5.X Hash support [syserr.hash]
21887</ins></p>
21888
21889<pre><ins>
21890template &lt;&gt; struct hash&lt;error_code&gt;;
21891</ins></pre>
21892
21893<blockquote><ins>
21894An explicit specialization of the class template hash (20.7.16 [unord.hash])
21895shall be provided
21896for the type <tt>error_code</tt> suitable for using this type as key in
21897unordered associative
21898containers (23.5 [unord]).
21899</ins></blockquote>
21900</blockquote>
21901</li>
21902
21903<li>
21904<p>
21905Add the following declarations to 30.3.1.1 [thread.thread.id] just after the
21906declaration of
21907the comparison operators:
21908</p>
21909
21910<blockquote><pre><ins>
21911template &lt;class T&gt; struct hash;
21912template &lt;&gt; struct hash&lt;thread::id&gt;;
21913</ins></pre></blockquote>
21914</li>
21915
21916<li>
21917<p>
21918Add a new paragraph at the end of 30.3.1.1 [thread.thread.id]:
21919</p>
21920
21921<blockquote>
21922<pre><ins>
21923template &lt;&gt; struct hash&lt;thread::id&gt;;
21924</ins></pre>
21925
21926<blockquote><ins>
21927An explicit specialization of the class template hash (20.7.16 [unord.hash])
21928shall be provided
21929for the type <tt>thread::id</tt> suitable for using this type as key in
21930unordered associative
21931containers (23.5 [unord]).
21932</ins></blockquote>
21933</blockquote>
21934</li>
21935
21936<li>
21937Issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#889">889</a> independently suggests moving the specialization
21938<tt>std::hash&lt;std::thread::id&gt;</tt> to header <tt>&lt;thread&gt;</tt>.
21939</li>
21940</ul>
21941
21942
21943
21944<p><b>Proposed resolution:</b></p>
21945<p>
21946Strike the following specializations declared in the <tt>&lt;functional&gt;</tt>
21947synopsis p2 20.7 [function.objects]
21948</p>
21949
21950<blockquote><pre><del>template &lt;&gt; struct hash&lt;std::string&gt;;</del>
21951<del>template &lt;&gt; struct hash&lt;std::u16string&gt;;</del>
21952<del>template &lt;&gt; struct hash&lt;std::u32string&gt;;</del>
21953<del>template &lt;&gt; struct hash&lt;std::wstring&gt;;</del>
21954
21955<del>template &lt;class Allocator&gt; struct hash&lt;std::vector&lt;bool, Allocator&gt; &gt;;</del>
21956<del>template &lt;std::size_t N&gt; struct hash&lt;std::bitset&lt;N&gt; &gt;;</del>
21957</pre></blockquote>
21958
21959<p>
21960Add the following declarations to the synopsis of <tt>&lt;string&gt;</tt> in
2196121.3 [string.classes]
21962</p>
21963
21964<blockquote><pre><ins>// 21.4.x hash support
21965template &lt;class T&gt; struct hash;
21966template &lt;&gt; struct hash&lt;string&gt;;
21967template &lt;&gt; struct hash&lt;u16string&gt;;
21968template &lt;&gt; struct hash&lt;u32string&gt;;
21969template &lt;&gt; struct hash&lt;wstring&gt;;</ins>
21970</pre></blockquote>
21971
21972<p>
21973Add a new clause 21.4.X
21974</p>
21975
21976<blockquote>
21977<p>
2197821.4.X Hash support [basic.string.hash]
21979</p>
21980
21981<pre>template &lt;&gt; struct hash&lt;string&gt;;
21982template &lt;&gt; struct hash&lt;u16string&gt;;
21983template &lt;&gt; struct hash&lt;u32string&gt;;
21984template &lt;&gt; struct hash&lt;wstring&gt;;
21985</pre>
21986
21987<blockquote>
21988Explicit specializations of the class template hash (20.7.16 [unord.hash])
21989shall be provided for the types <tt>string</tt>, <tt>u16string</tt>,
21990<tt>u32string</tt> and <tt>wstring</tt> suitable for using these types as keys in
21991unordered associative containers (23.5 [unord]).
21992</blockquote>
21993</blockquote>
21994
21995<p>
21996Add the following declarations to the synopsis of <tt>&lt;vector&gt;</tt> in 
2199723.3 [sequences]
21998</p>
21999
22000<blockquote><pre><ins>
22001// 21.4.x hash support
22002template &lt;class T&gt; struct hash;
22003template &lt;class Allocator&gt; struct hash&lt;vector&lt;bool, Allocator&gt;&gt;;
22004</ins></pre></blockquote>
22005
22006<p>
22007Add a new paragraph to the end of 23.3.7 [vector.bool]
22008</p>
22009
22010<blockquote><pre>template &lt;class Allocator&gt; struct hash&lt;vector&lt;bool, Allocator&gt;&gt;;
22011</pre>
22012<blockquote>
22013A partial specialization of the class template hash (20.7.16 [unord.hash])
22014shall be provided for vectors of boolean values suitable for use as a key
22015in unordered associative containers (23.5 [unord]).
22016</blockquote>
22017</blockquote>
22018
22019<p>
22020Add the following declarations to the synopsis of <tt>&lt;bitset&gt;</tt>
22021in 20.3.7 [template.bitset]
22022</p>
22023
22024<blockquote><pre><ins>
22025// 20.3.6.X hash support
22026template &lt;class T&gt; struct hash;
22027template &lt;size_t N&gt; struct hash&lt;bitset&lt;N&gt; &gt;;
22028</ins></pre></blockquote>
22029
22030<p>
22031Add a new subclause 20.3.6.X [bitset.hash]
22032</p>
22033
22034<blockquote>
22035<p>
2203620.3.6.X bitset hash support [bitset.hash]
22037</p>
22038
22039<pre>template &lt;size_t N&gt; struct hash&lt;bitset&lt;N&gt; &gt;;
22040</pre>
22041
22042<blockquote>
22043A partial specialization of the class template hash
22044(20.7.16 [unord.hash]) shall be provided for bitsets suitable for use as a key in
22045unordered associative containers (23.5 [unord]).
22046</blockquote>
22047</blockquote>
22048
22049
22050
22051
22052
22053
22054<hr>
22055<h3><a name="1183"></a>1183. <tt>basic_ios::set_rdbuf</tt> may break class invariants</h3>
22056<p><b>Section:</b> 27.5.4.2 [basic.ios.members] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
22057 <b>Submitter:</b> Daniel Kr�gler <b>Opened:</b> 2009-07-28  <b>Last modified:</b> 2009-10-22</p>
22058<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#basic.ios.members">active issues</a> in [basic.ios.members].</p>
22059<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#basic.ios.members">issues</a> in [basic.ios.members].</p>
22060<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
22061<p><b>Discussion:</b></p>
22062<p>
22063The protected member function <tt>set_rdbuf</tt> had been added during the
22064process of adding move and swap semantics to IO classes. A relevant
22065property of this function is described by it's effects in
2206627.5.4.2 [basic.ios.members]/19:
22067</p>
22068
22069<blockquote>
22070<i>Effects:</i> Associates the <tt>basic_streambuf</tt> object pointed to by sb with
22071this stream without calling <tt>clear()</tt>.
22072</blockquote>
22073
22074<p>
22075This means that implementors of or those who derive from existing IO classes
22076could cause an internal state where the stream buffer could be 0, but the
22077IO class has the state <tt>good()</tt>. This would break several currently existing
22078implementations which rely on the fact that setting a stream buffer via the
22079currently only ways, i.e. either by calling
22080</p>
22081
22082<blockquote><pre>void init(basic_streambuf&lt;charT,traits&gt;* sb);
22083</pre></blockquote>
22084
22085<p>
22086or by calling
22087</p>
22088
22089<blockquote><pre>basic_streambuf&lt;charT,traits&gt;* rdbuf(basic_streambuf&lt;charT,traits&gt;* sb);
22090</pre></blockquote>
22091
22092<p>
22093to set <tt>rdstate()</tt> to <tt>badbit</tt>, if the buffer is 0. This has the effect that many
22094internal functions can simply check <tt>rdstate()</tt> instead of <tt>rdbuf()</tt> for being 0.
22095</p>
22096
22097<p>
22098I therefore suggest that a requirement is added for callers of <tt>set_rdbuf</tt> to
22099set a non-0 value.
22100</p>
22101
22102<p><i>[
221032009-10 Santa Cruz:
22104]</i></p>
22105
22106
22107<blockquote>
22108Moved to Open.  Martin volunteers to provide new wording, where
22109<tt>set_rdbuf()</tt> sets the <tt>badbit</tt> but does not cause an
22110exception to be thrown like a call to <tt>clear()</tt> would.
22111</blockquote>
22112
22113<p><i>[
221142009-10-20 Martin provides wording:
22115]</i></p>
22116
22117
22118
22119
22120<p><b>Proposed resolution:</b></p>
22121<p>
22122Change 27.5.4.2 [basic.ios.members] around p. 19 as indicated:
22123</p>
22124
22125<blockquote><pre>void set_rdbuf(basic_streambuf&lt;charT, traits&gt;* sb);
22126</pre>
22127
22128<blockquote>
22129<p><del>
22130<i>Effects:</i> Associates the <tt>basic_streambuf</tt> object pointed
22131to by <tt>sb</tt> with this stream without calling <tt>clear()</tt>.
22132<i>Postconditions:</i> <tt>rdbuf() == sb</tt>.
22133</del></p>
22134
22135<p><ins>
22136<i>Effects:</i> As if:
22137</ins></p>
22138
22139<blockquote><pre><ins>
22140iostate state = rdstate();
22141try { rdbuf(sb); }
22142catch(ios_base::failure) {
22143   if (0 == (state &amp; ios_base::badbit))
22144       unsetf(badbit);
22145}
22146</ins></pre></blockquote>
22147
22148<p>
22149<i>Throws:</i> Nothing.
22150</p>
22151
22152</blockquote>
22153</blockquote>
22154
22155
22156<p><b>Rationale:</b></p>
22157We need to be able to call <tt>set_rdbuf()</tt> on stream objects
22158for which (<tt>rdbuf() == 0</tt>) holds without causing <tt>ios_base::failure</tt> to
22159be thrown. We also don't want <tt>badbit</tt> to be set as a result of
22160setting <tt>rdbuf()</tt> to 0 if it wasn't set before the call. This changed
22161Effects clause maintains the current behavior (as of N2914) without
22162requiring that <tt>sb</tt> be non-null.
22163
22164
22165
22166
22167
22168<hr>
22169<h3><a name="1185"></a>1185. iterator categories and output iterators</h3>
22170<p><b>Section:</b> 24.2 [iterator.requirements] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
22171 <b>Submitter:</b> Alisdair Meredith <b>Opened:</b> 2009-07-31  <b>Last modified:</b> 2009-07-31</p>
22172<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#iterator.requirements">active issues</a> in [iterator.requirements].</p>
22173<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#iterator.requirements">issues</a> in [iterator.requirements].</p>
22174<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
22175<p><b>Discussion:</b></p>
22176<p>
22177(wording relative to
22178<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2723.pdf">N2723</a>
22179pending new working paper)
22180</p>
22181
22182<p>
22183According to p3 24.2 [iterator.requirements], Forward iterators,
22184Bidirectional iterators and Random Access iterators all satisfy the
22185requirements for an Output iterator:
22186</p>
22187
22188<blockquote>
22189XXX iterators satisfy all the requirements of the input and output iterators
22190and can be used whenever either kind is specified ...
22191</blockquote>
22192
22193<p>
22194Meanwhile, p4 goes on to contradict this:
22195</p>
22196
22197<blockquote>
22198Besides its category, a forward, bidirectional, or random access
22199iterator can also be mutable or constant...
22200</blockquote>
22201
22202<blockquote>
22203... Constant iterators do not satisfy the requirements for output iterators
22204</blockquote>
22205
22206<p>
22207The latter seems to be the overriding concern, as the iterator tag
22208hierarchy does not define <tt>forward_iterator_tag</tt> as multiply derived from
22209both <tt>input_iterator_tag</tt> and <tt>output_iterator_tag</tt>.
22210</p>
22211
22212<p>
22213The work on concepts for iterators showed us that output iterator really
22214is fundamentally a second dimension to the iterator categories, rather
22215than part of the linear input -&gt; forward -&gt; bidirectional -&gt;
22216random-access sequence.  It would be good to clear up these words to
22217reflect that, and separately list output iterator requirements in the
22218requires clauses for the appropriate algorithms and operations.
22219</p>
22220
22221
22222<p><b>Proposed resolution:</b></p>
22223
22224
22225
22226
22227
22228<hr>
22229<h3><a name="1186"></a>1186. Forward list could model a stack</h3>
22230<p><b>Section:</b> 23.3.5.3 [stack] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#NAD%20Concepts">Tentatively NAD Concepts</a>
22231 <b>Submitter:</b> Alisdair Meredith <b>Opened:</b> 2009-07-31  <b>Last modified:</b> 2009-11-02</p>
22232<p><b>Discussion:</b></p>
22233<p>
22234The library template <tt>forward_list</tt> could easily model the idea of a
22235<tt>stack</tt>, where the operations work on the front of the list rather than
22236the back.  However, the standard library <tt>stack</tt> adaptor cannot support
22237this.
22238</p>
22239
22240<p>
22241It would be relatively easy to write a partial specialization for <tt>stack</tt>
22242to support <tt>forward_list</tt>, but that opens the question of which header to
22243place it in.  A much better solution would be to add a <tt>concept_map</tt> for
22244the <tt>StackLikeContainer</tt> concept to the <tt>&lt;forward_list&gt;</tt> header and then
22245everything just works, including a user's own further uses in a
22246stack-like context.
22247</p>
22248
22249<p>
22250Therefore while I am submitting the issue now so that it is on record, I
22251<em>strongly recommend</em> we resolve as "NAD Concepts" as any non-concepts
22252based solution will be inferior to the final goal, and the feature is
22253not so compelling it must be supported ahead of the concepts-based
22254library.
22255</p>
22256
22257<p><i>[
222582009-11-02 Howard adds:
22259]</i></p>
22260
22261
22262<blockquote>
22263Moved to Tentatively NAD Concepts after 5 positive votes on c++std-lib.
22264</blockquote>
22265
22266
22267<p><b>Proposed resolution:</b></p>
22268
22269
22270
22271
22272
22273<hr>
22274<h3><a name="1187"></a>1187. std::decay</h3>
22275<p><b>Section:</b> 20.6.7 [meta.trans.other] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
22276 <b>Submitter:</b> Jason Merrill <b>Opened:</b> 2009-08-07  <b>Last modified:</b> 2009-08-22</p>
22277<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#meta.trans.other">issues</a> in [meta.trans.other].</p>
22278<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
22279<p><b>Discussion:</b></p>
22280<p>
22281I notice that <tt>std::decay</tt> is specified to strip the cv-quals from
22282anything but an array or pointer.  This seems incorrect for values of
22283class type, since class rvalues can have cv-qualified type (3.10 [basic.lval]/9).
22284</p>
22285
22286<p><i>[
222872009-08-09 Howard adds:
22288]</i></p>
22289
22290
22291<blockquote>
22292See the thread starting with c++std-lib-24568 for further discussion.  And
22293here is a convenience link to the
22294<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2006/n2069.html">original proposal</a>.
22295Also see the closely related issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#705">705</a>.
22296</blockquote>
22297
22298
22299<p><b>Proposed resolution:</b></p>
22300
22301<p>
22302Add a note to <tt>decay</tt> in 20.6.7 [meta.trans.other]:
22303</p>
22304
22305<blockquote>
22306[<i>Note:</i> This behavior is similar to the lvalue-to-rvalue (4.1),
22307array-to-pointer (4.2), and function-to-pointer (4.3) conversions
22308applied when an lvalue expression is used as an rvalue, but also strips
22309cv-qualifiers from class types in order to more closely model by-value
22310argument passing. &#8212; <i>end note</i>]
22311</blockquote>
22312
22313
22314
22315
22316
22317
22318
22319
22320<hr>
22321<h3><a name="1188"></a>1188. Unordered containers should have a minimum load factor as well as a maximum</h3>
22322<p><b>Section:</b> 23.2.5 [unord.req], 23.5 [unord] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
22323 <b>Submitter:</b> Matt Austern <b>Opened:</b> 2009-08-10  <b>Last modified:</b> 2009-08-11</p>
22324<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#unord.req">active issues</a> in [unord.req].</p>
22325<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#unord.req">issues</a> in [unord.req].</p>
22326<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
22327<p><b>Discussion:</b></p>
22328<p>
22329Unordered associative containers have a notion of a maximum load factor:
22330when the number of elements grows large enough, the containers
22331automatically perform a rehash so that the number of elements per bucket
22332stays below a user-specified bound. This ensures that the hash table's
22333performance characteristics don't change dramatically as the size
22334increases.
22335</p>
22336
22337<p>
22338For similar reasons, Google has found it useful to specify a minimum
22339load factor: when the number of elements shrinks by a large enough, the
22340containers automatically perform a rehash so that the number of elements
22341per bucket stays above a user-specified bound. This is useful for two
22342reasons. First, it prevents wasting a lot of memory when an unordered
22343associative container grows temporarily. Second, it prevents amortized
22344iteration time from being arbitrarily large; consider the case of a hash
22345table with a billion buckets and only one element. (This was discussed
22346even before TR1 was published; it was TR issue 6.13, which the LWG
22347closed as NAD on the grounds that it was a known design feature.
22348However, the LWG did not consider the approach of a minimum load
22349factor.)
22350</p>
22351
22352<p>
22353The only interesting question is when shrinking is allowed. In principle
22354the cleanest solution would be shrinking on erase, just as we grow on
22355insert. However, that would be a usability problem; it would break a
22356number of common idioms involving erase. Instead, Google's hash tables
22357only shrink on insert and rehash.
22358</p>
22359
22360<p>
22361The proposed resolution allows, but does not require, shrinking in
22362rehash, mostly because a postcondition for rehash that involves the
22363minimum load factor would be fairly complicated. (It would probably have
22364to involve a number of special cases and it would probably have to
22365mention yet another parameter, a minimum bucket count.)
22366</p>
22367
22368<p>
22369The current behavior is equivalent to a minimum load factor of 0. If we
22370specify that 0 is the default, this change will have no impact on
22371backward compatibility.
22372</p>
22373
22374
22375<p><b>Proposed resolution:</b></p>
22376<p>
22377Add two new rows, and change rehash's postcondition in the unordered
22378associative container requirements table in 23.2.5 [unord.req]:
22379</p>
22380
22381<blockquote>
22382<table border="1">
22383<caption>Table 87 &#8212; Unordered associative container requirements
22384(in addition to container)</caption>
22385
22386<tbody><tr>
22387<th>Expression</th><th>Return type</th><th>Assertion/note pre-/post-condition</th>
22388<th>Complexity</th>
22389</tr>
22390<tr>
22391<td><ins>
22392<tt>a.min_load_factor()</tt>
22393</ins></td>
22394<td><ins>
22395<tt>float</tt>
22396</ins></td>
22397<td><ins>
22398Returns a non-negative number that the container attempts to keep the
22399load factor greater than or equal to. The container automatically
22400decreases the number of buckets as necessary to keep the load factor
22401above this number.
22402</ins></td>
22403<td><ins>
22404constant
22405</ins></td>
22406</tr>
22407
22408<tr>
22409<td><ins><tt>a.min_load_factor(z)</tt></ins></td>
22410<td><ins><tt>void</tt></ins></td>
22411<td><ins>Pre: <tt>z</tt> shall be non-negative. Changes the container's minimum
22412load factor, using <tt>z</tt> as a hint. [<i>Footnote:</i> the minimum
22413load factor should be significantly smaller than the maximum. 
22414If <tt>z</tt> is too large, the implementation may reduce it to a more sensible value.]
22415</ins></td>
22416<td><ins>
22417constant
22418</ins></td>
22419</tr>
22420<tr>
22421<td><tt>a.rehash(n)</tt></td>
22422<td><tt>void</tt></td>
22423<td>
22424Post: <ins><tt>a.bucket_count() &gt;= n</tt>, and <tt>a.size() &lt;= a.bucket_count()
22425* a.max_load_factor()</tt>. [<i>Footnote:</i> It is intentional that the
22426postcondition does not mention the minimum load factor.
22427This member function is primarily intended for cases where the user knows
22428that the container's size will increase soon, in which case the container's
22429load factor will temporarily fall below <tt>a.min_load_factor()</tt>.]</ins>
22430<del>
22431<tt>a.bucket_cout &gt; a.size() / a.max_load_factor()</tt> and <tt>a.bucket_count()
22432&gt;= n</tt>.
22433</del>
22434</td>
22435<td>
22436Average case linear in <tt>a.size()</tt>, worst case quadratic.
22437</td>
22438</tr>
22439</tbody></table>
22440</blockquote>
22441
22442<p>
22443Add a footnote to 23.2.5 [unord.req] p12:
22444</p>
22445
22446<blockquote>
22447<p>
22448The insert members shall not affect the validity of references to
22449container elements, but may invalidate all iterators to the container.
22450The erase members shall invalidate only iterators and references to the
22451erased elements.
22452</p>
22453
22454<blockquote><ins>
22455[A consequence of these requirements is that while insert may change the
22456number of buckets, erase may not. The number of buckets may be reduced
22457on calls to insert or rehash.]
22458</ins></blockquote>
22459</blockquote>
22460
22461<p>
22462Change paragraph 13:
22463</p>
22464
22465<blockquote>
22466The insert members shall not affect the validity of iterators if
22467<del><tt>(N+n) &lt; z * B</tt></del> <ins><tt>zmin * B &lt;= (N+n) &lt;= zmax * B</tt></ins>,
22468where <tt>N</tt> is the number of elements in
22469the container prior to the insert operation, <tt>n</tt> is the number of
22470elements inserted, <tt>B</tt> is the container's bucket count,
22471<ins><tt>zmin</tt> is the container's minimum load factor,</ins>
22472and <tt>z<ins>max</ins></tt> is the container's maximum load factor.
22473</blockquote>
22474
22475<p>
22476Add to the <tt>unordered_map</tt> class synopsis in section 23.5.1 [unord.map],
22477the <tt>unordered_multimap</tt> class synopsis
22478in 23.5.2 [unord.multimap], the <tt>unordered_set</tt> class synopsis in
2247923.5.3 [unord.set], and the <tt>unordered_multiset</tt> class synopsis
22480in 23.5.4 [unord.multiset]:
22481</p>
22482
22483<blockquote><pre><ins>
22484float min_load_factor() const;
22485void min_load_factor(float z);
22486</ins></pre></blockquote>
22487
22488<p>
22489In 23.5.1.1 [unord.map.cnstr], 23.5.2.1 [unord.multimap.cnstr], 23.5.3.1 [unord.set.cnstr], and
2249023.5.4.1 [unord.multiset.cnstr], change:
22491</p>
22492
22493<blockquote>
22494... <tt>max_load_factor()</tt> returns 1.0 <ins>and
22495<tt>min_load_factor()</tt> returns 0</ins>.
22496</blockquote>
22497
22498
22499
22500
22501
22502<hr>
22503<h3><a name="1189"></a>1189. Awkward interface for changing the number of buckets in an unordered associative container</h3>
22504<p><b>Section:</b> 23.2.5 [unord.req], 23.5 [unord] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Tentatively Ready</a>
22505 <b>Submitter:</b> Matt Austern <b>Opened:</b> 2009-08-10  <b>Last modified:</b> 2009-10-28</p>
22506<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#unord.req">active issues</a> in [unord.req].</p>
22507<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#unord.req">issues</a> in [unord.req].</p>
22508<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Tentatively%20Ready">Tentatively Ready</a> status.</p>
22509<p><b>Discussion:</b></p>
22510<p>
22511Consider a typical use case: I create an <tt>unordered_map</tt> and then start
22512adding elements to it one at a time. I know that it will eventually need
22513to store a few million elements, so, for performance reasons, I would
22514like to reserve enough capacity that none of the calls to <tt>insert</tt> will
22515trigger a rehash.
22516</p>
22517
22518<p>
22519Unfortunately, the existing interface makes this awkward. The user
22520naturally sees the problem in terms of the number of elements, but the
22521interface presents it as buckets. If <tt>m</tt> is the map and <tt>n</tt> is the expected
22522number of elements, this operation is written <tt>m.rehash(n /
22523m.max_load_factor())</tt> &#8212; not very novice friendly.
22524</p>
22525
22526<p><i>[
225272009-09-30 Daniel adds:
22528]</i></p>
22529
22530
22531<blockquote>
22532I recommend to replace "<tt>resize</tt>" by a different name like
22533"<tt>reserve</tt>", because that would better match the intended
22534use-case. Rational: Any existing resize function has the on-success
22535post-condition that the provided size is equal to <tt>size()</tt>, which
22536is not satisfied for the proposal. Reserve seems to fit the purpose of
22537the actual renaming suggestion.
22538</blockquote>
22539
22540<p><i>[
225412009-10-28 Ganesh summarizes alternative resolutions and expresses a
22542strong preference for the second (and opposition to the first):
22543]</i></p>
22544
22545
22546<blockquote>
22547<ol>
22548<li>
22549<p>
22550In the unordered associative container requirements (23.2.5 [unord.req]),
22551remove the row for
22552rehash and replace it with:
22553</p>
22554
22555<blockquote>
22556<table border="1">
22557<caption>Table 87 &#8212; Unordered associative container requirements
22558(in addition to container)</caption>
22559
22560<tbody><tr>
22561<th>Expression</th><th>Return type</th><th>Assertion/note pre-/post-condition</th>
22562<th>Complexity</th>
22563</tr>
22564<tr>
22565<td><tt>a.<del>rehash</del><ins>reserve</ins>(n)</tt></td>
22566<td><tt>void</tt></td>
22567<td>
22568Post: <tt>a.bucket_count &gt; <ins>max(</ins>a.size()<ins>, n)</ins>
22569/ a.max_load_factor()</tt><del> and <tt>a.bucket_count()
22570&gt;= n</tt></del>.
22571</td>
22572<td>
22573Average case linear in <tt>a.size()</tt>, worst case quadratic.
22574</td>
22575</tr>
22576</tbody></table>
22577</blockquote>
22578
22579<p>
22580Make the corresponding change in the class synopses in 23.5.1
22581[unord.map], 23.5.2 [unord.multimap], 23.5.3 [unord.set], and 23.5.4
22582[unord.multiset].
22583</p>
22584</li>
22585<li>
22586
22587<p>
22588In 23.2.5 [unord.req]/9, table 98, append a new row after the last one:
22589</p>
22590
22591<blockquote>
22592<table border="1">
22593<caption>Table 87 &#8212; Unordered associative container requirements
22594(in addition to container)</caption>
22595
22596<tbody><tr>
22597<th>Expression</th><th>Return type</th><th>Assertion/note pre-/post-condition</th>
22598<th>Complexity</th>
22599</tr>
22600<tr>
22601<td><tt>a.rehash(n)</tt></td>
22602<td><tt>void</tt></td>
22603<td>
22604Post: <tt>a.bucket_count &gt; a.size()
22605/ a.max_load_factor()</tt> and <tt>a.bucket_count()
22606&gt;= n</tt>.
22607</td>
22608<td>
22609Average case linear in <tt>a.size()</tt>, worst case quadratic.
22610</td>
22611</tr>
22612<tr>
22613<td><ins>
22614<tt>a.reserve(n)</tt>
22615</ins></td>
22616<td><ins>
22617<tt>void</tt>
22618</ins></td>
22619<td><ins>
22620Same as <tt>a.rehash(ceil(n / a.max_load_factor()))</tt>
22621</ins></td>
22622<td><ins>
22623Average case linear in <tt>a.size()</tt>, worst case quadratic.
22624</ins></td>
22625</tr>
22626</tbody></table>
22627</blockquote>
22628
22629<p>
22630In 23.5.1 [unord.map]/3 in the definition of class template <tt>unordered_map</tt>, in
2263123.5.2 [unord.multimap]/3 in the definition of class template <tt>unordered_multimap</tt>, in
2263223.5.3 [unord.set]/3 in the definition of class template <tt>unordered_set</tt> and in
2263323.5.4 [unord.multiset]/3 in the definition of class template <tt>unordered_multiset</tt>, add the
22634following line after member function <tt>rehash()</tt>:
22635</p>
22636
22637<blockquote><pre>void reserve(size_type n);
22638</pre></blockquote>
22639
22640</li>
22641</ol>
22642</blockquote>
22643
22644<p><i>[
226452009-10-28 Howard:
22646]</i></p>
22647
22648
22649<blockquote>
22650<p>
22651Moved to Tentatively Ready after 5 votes in favor of Ganesh's option 2 above.
22652The original proposed wording now appears here:
22653</p>
22654
22655<blockquote>
22656<p>
22657Informally: instead of providing <tt>rehash(n)</tt> provide <tt>resize(n)</tt>, with the
22658semantics "make the container a good size for <tt>n</tt> elements".
22659</p>
22660
22661<p>
22662In the unordered associative container requirements (23.2.5 [unord.req]),
22663remove the row for
22664rehash and replace it with:
22665</p>
22666
22667<blockquote>
22668<table border="1">
22669<caption>Table 87 &#8212; Unordered associative container requirements
22670(in addition to container)</caption>
22671
22672<tbody><tr>
22673<th>Expression</th><th>Return type</th><th>Assertion/note pre-/post-condition</th>
22674<th>Complexity</th>
22675</tr>
22676<tr>
22677<td><tt>a.<del>rehash</del><ins>resize</ins>(n)</tt></td>
22678<td><tt>void</tt></td>
22679<td>
22680Post: <tt>a.bucket_count &gt; <ins>max(</ins>a.size()<ins>, n)</ins>
22681/ a.max_load_factor()</tt><del> and <tt>a.bucket_count()
22682&gt;= n</tt></del>.
22683</td>
22684<td>
22685Average case linear in <tt>a.size()</tt>, worst case quadratic.
22686</td>
22687</tr>
22688</tbody></table>
22689</blockquote>
22690
22691<p>Make the corresponding change in the class synopses in 23.5.1
22692[unord.map], 23.5.2 [unord.multimap], 23.5.3 [unord.set], and 23.5.4
22693[unord.multiset].
22694</p>
22695
22696</blockquote>
22697</blockquote>
22698
22699
22700<p><b>Proposed resolution:</b></p>
22701<p>
22702In 23.2.5 [unord.req]/9, table 98, append a new row after the last one:
22703</p>
22704
22705<blockquote>
22706<table border="1">
22707<caption>Table 87 &#8212; Unordered associative container requirements
22708(in addition to container)</caption>
22709
22710<tbody><tr>
22711<th>Expression</th><th>Return type</th><th>Assertion/note pre-/post-condition</th>
22712<th>Complexity</th>
22713</tr>
22714<tr>
22715<td><tt>a.rehash(n)</tt></td>
22716<td><tt>void</tt></td>
22717<td>
22718Post: <tt>a.bucket_count &gt; a.size()
22719/ a.max_load_factor()</tt> and <tt>a.bucket_count()
22720&gt;= n</tt>.
22721</td>
22722<td>
22723Average case linear in <tt>a.size()</tt>, worst case quadratic.
22724</td>
22725</tr>
22726<tr>
22727<td><ins>
22728<tt>a.reserve(n)</tt>
22729</ins></td>
22730<td><ins>
22731<tt>void</tt>
22732</ins></td>
22733<td><ins>
22734Same as <tt>a.rehash(ceil(n / a.max_load_factor()))</tt>
22735</ins></td>
22736<td><ins>
22737Average case linear in <tt>a.size()</tt>, worst case quadratic.
22738</ins></td>
22739</tr>
22740</tbody></table>
22741</blockquote>
22742
22743<p>
22744In 23.5.1 [unord.map]/3 in the definition of class template <tt>unordered_map</tt>, in
2274523.5.2 [unord.multimap]/3 in the definition of class template <tt>unordered_multimap</tt>, in
2274623.5.3 [unord.set]/3 in the definition of class template <tt>unordered_set</tt> and in
2274723.5.4 [unord.multiset]/3 in the definition of class template <tt>unordered_multiset</tt>, add the
22748following line after member function <tt>rehash()</tt>:
22749</p>
22750
22751<blockquote><pre>void reserve(size_type n);
22752</pre></blockquote>
22753
22754
22755
22756
22757
22758<hr>
22759<h3><a name="1190"></a>1190. Setting the maximum load factor should return the previous value</h3>
22760<p><b>Section:</b> 23.2.5 [unord.req], 23.5 [unord] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
22761 <b>Submitter:</b> Matt Austern <b>Opened:</b> 2009-08-10  <b>Last modified:</b> 2009-08-11</p>
22762<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#unord.req">active issues</a> in [unord.req].</p>
22763<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#unord.req">issues</a> in [unord.req].</p>
22764<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
22765<p><b>Discussion:</b></p>
22766<p>
22767The unordered associative container requirements table specifies that
22768<tt>a.set_max_load_factor(z)</tt> has return type <tt>void</tt>. However, there is a
22769useful piece of information to return: the previous value. Users who
22770don't need it can always ignore it.
22771</p>
22772
22773
22774<p><b>Proposed resolution:</b></p>
22775<p>
22776In the unordered associative container requirements table, change:
22777</p>
22778
22779<blockquote>
22780<table border="1">
22781<caption>Table 87 &#8212; Unordered associative container requirements
22782(in addition to container)</caption>
22783
22784<tbody><tr>
22785<th>Expression</th><th>Return type</th><th>Assertion/note pre-/post-condition</th>
22786<th>Complexity</th>
22787</tr>
22788
22789<tr>
22790<td><tt>a.max_load_factor(z)</tt></td>
22791<td><tt><del>void</del> <ins>float</ins></tt></td>
22792<td>Pre: <tt>z</tt> shall be positive. Changes the container's maximum
22793<del>load</del> load factor, using <tt>z</tt> as a hint.
22794<ins>Returns: the previous value of
22795<tt>a.max_load_factor()</tt>.</ins>
22796</td>
22797<td>
22798constant
22799</td>
22800</tr>
22801<tr></tr>
22802</tbody></table>
22803</blockquote>
22804
22805<p>
22806Change the return type of <tt>set_max_load_factor</tt>
22807in the class synopses in 23.5.1 [unord.map], 23.5.2 [unord.multimap],  23.5.3 [unord.set],
22808and 23.5.4 [unord.multiset].
22809</p>
22810
22811<p>
22812If issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1188">1188</a> is also accepted, make the same changes for
22813<tt>min_load_factor</tt>.
22814</p>
22815
22816
22817
22818
22819
22820<hr>
22821<h3><a name="1191"></a>1191. <tt>tuple get</tt> API should respect rvalues</h3>
22822<p><b>Section:</b> 20.5.2.6 [tuple.elem] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
22823 <b>Submitter:</b> Alisdair Meredith <b>Opened:</b> 2009-08-18  <b>Last modified:</b> 2009-10-31</p>
22824<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
22825<p><b>Discussion:</b></p>
22826<p>
22827The <tt>tuple get</tt> API should respect rvalues.  This would allow for moving a
22828single element out of a <tt>tuple</tt>-like type.
22829</p>
22830
22831<p><i>[
228322009-10-30 Alisdair adds:
22833]</i></p>
22834
22835
22836<blockquote>
22837<p>
22838The issue of rvalue overloads of get for tuple-like types was briefly
22839discussed in Santa Cruz.
22840</p>
22841
22842<p>
22843The feedback was this would be welcome, but we need full wording for the
22844other types (<tt>pair</tt> and <tt>array</tt>) before advancing.
22845</p>
22846
22847<p>
22848I suggest the issue moves to Open from New as it has been considered,
22849feedback given, and it has not (yet) been rejected as NAD.
22850</p>
22851</blockquote>
22852
22853
22854
22855<p><b>Proposed resolution:</b></p>
22856<p>
22857Add the following signature to p2 20.5.1 [tuple.general]
22858</p>
22859
22860<blockquote><pre><ins>
22861template &lt;size_t I, class ... Types&gt;
22862typename tuple_element&lt;I, tuple&lt;Types...&gt; &gt;::type&amp;&amp; get(tuple&lt;Types...&gt; &amp;&amp;);
22863</ins></pre></blockquote>
22864
22865<p>
22866And again to 20.5.2.6 [tuple.elem].
22867</p>
22868
22869<blockquote><pre><ins>
22870template &lt;size_t I, class ... Types&gt;
22871typename tuple_element&lt;I, tuple&lt;Types...&gt; &gt;::type&amp;&amp; get(tuple&lt;Types...&gt;&amp;&amp; t);
22872</ins></pre>
22873
22874<blockquote>
22875<p><ins>
22876<i>Effects:</i> Equivalent to <tt>return std::forward&lt;typename tuple_element&lt;I, tuple&lt;Types...&gt; &gt;::type&amp;&amp;&gt;(get&lt;I&gt;(t));</tt>
22877</ins></p>
22878
22879
22880<p><ins>
22881[<i>Note:</i> If a <tt>T</tt> in <tt>Types</tt> is some reference type <tt>X&amp;</tt>,
22882the return type is <tt>X&amp;</tt>, not <tt>X&amp;&amp;</tt>.
22883However, if the element type is non-reference type <tt>T</tt>,
22884the return type is <tt>T&amp;&amp;</tt>. &#8212; <i>end note</i>]
22885</ins></p>
22886
22887</blockquote>
22888</blockquote>
22889
22890<p>
22891Add the following signature to p1 20.3 [utility]
22892</p>
22893
22894<blockquote><pre><ins>
22895template &lt;size_t I, class T1, class T2&gt;
22896typename tuple_element&lt;I, pair&lt;T1,T2&gt; &gt;::type&amp;&amp; get(pair&lt;T1, T2&gt;&amp;&amp;);
22897</ins></pre></blockquote>
22898
22899<p>
22900And to p5 20.3.5 [pair.astuple]
22901</p>
22902
22903<blockquote><pre><ins>
22904template &lt;size_t I, class T1, class T2&gt;
22905typename tuple_element&lt;I, pair&lt;T1,T2&gt; &gt;::type&amp;&amp; get(pair&lt;T1, T2&gt;&amp;&amp; p);
22906</ins></pre>
22907
22908<blockquote>
22909<p><ins>
22910<i>Returns:</i> If <tt>I == 0</tt> returns <tt>std::forward&lt;T1&amp;&amp;&gt;(p.first)</tt>;
22911if <tt>I == 1</tt>
22912returns <tt>std::forward&lt;T2&amp;&amp;&gt;(p.second)</tt>; otherwise the program is ill-formed.
22913</ins></p>
22914
22915<p><ins>
22916<i>Throws:</i> Nothing.
22917</ins></p>
22918
22919</blockquote>
22920
22921</blockquote>
22922
22923<p>
22924Add the following signature to 23.3 [sequences] <tt>&lt;array&gt;</tt> synopsis
22925</p>
22926
22927<blockquote><pre><ins>template &lt;size_t I, class T, size_t N&gt;
22928T&amp;&amp; get(array&lt;T,N&gt; &amp;&amp;);
22929</ins></pre></blockquote>
22930
22931<p>
22932And after p8 23.3.1.7 [array.tuple]
22933</p>
22934
22935<blockquote><pre><ins>template &lt;size_t I, class T, size_t N&gt;
22936T&amp;&amp; get(array&lt;T,N&gt; &amp;&amp; a);
22937</ins></pre>
22938
22939<blockquote><ins>
22940<i>Effects:</i> Equivalent to <tt>return std::move(get&lt;I&gt;(a));</tt>
22941</ins></blockquote>
22942</blockquote>
22943
22944
22945
22946
22947
22948
22949<hr>
22950<h3><a name="1192"></a>1192. <tt>basic_string</tt> missing definitions for <tt>cbegin</tt> / <tt>cend</tt> / <tt>crbegin</tt> / <tt>crend</tt></h3>
22951<p><b>Section:</b> 21.4.3 [string.iterators] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Tentatively Ready</a>
22952 <b>Submitter:</b> Jonathan Wakely <b>Opened:</b> 2009-08-14  <b>Last modified:</b> 2009-10-29</p>
22953<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Tentatively%20Ready">Tentatively Ready</a> status.</p>
22954<p><b>Discussion:</b></p>
22955<p>
22956Unlike the containers in clause 23, <tt>basic_string</tt> has definitions for
22957<tt>begin()</tt> and <tt>end()</tt>, but these have not been updated to include <tt>cbegin</tt>,
22958<tt>cend</tt>, <tt>crbegin</tt> and <tt>crend</tt>.
22959</p>
22960
22961<p><i>[
229622009-10-28 Howard:
22963]</i></p>
22964
22965
22966<blockquote>
22967Moved to Tentatively NAD after 5 positive votes on c++std-lib.  Added
22968rationale.
22969</blockquote>
22970
22971<p><i>[
229722009-10-28 Alisdair disagrees:
22973]</i></p>
22974
22975
22976<blockquote>
22977<p>
22978I'm going to have to speak up as the dissenting voice.
22979</p>
22980
22981<p>
22982I agree the issue could be handled editorially, and that would be my
22983preference if Pete feels this is appropriate. Failing that, I really
22984think this issue should be accepted and moved to ready.  The other
22985begin/end functions all have a semantic definition for this template,
22986and it is confusing if a small few are missing.
22987</p>
22988
22989<p>
22990I agree that an alternative would be to strike <em>all</em> the definitions for
22991<tt>begin/end/rbegin/rend</tt> and defer completely to the requirements tables in
22992clause 23.  I think that might be confusing without a forward reference
22993though, as those tables are defined in a *later* clause than the
22994basic_string template itself.  If someone wants to pursue this I would
22995support it, but recommend it as a separate issue.
22996</p>
22997
22998<p>
22999So my preference is strongly to move Ready over NAD, and a stronger
23000preference for NAD Editorial if Pete is happy to make these changes.
23001</p>
23002
23003</blockquote>
23004
23005<p><i>[
230062009-10-29 Howard:
23007]</i></p>
23008
23009
23010<blockquote>
23011Moved to Tentatively Ready after 5 positive votes on c++std-lib.  Removed
23012rationale to mark it NAD.  :-)
23013</blockquote>
23014
23015
23016
23017<p><b>Proposed resolution:</b></p>
23018<p>
23019Add to 21.4.3 [string.iterators]
23020</p>
23021
23022<blockquote><pre>iterator       begin();
23023const_iterator begin() const;
23024<ins>const_iterator cbegin() const;</ins>
23025</pre>
23026
23027<p>...</p>
23028
23029<pre>iterator       end();
23030const_iterator end() const;
23031<ins>const_iterator cend() const;</ins>
23032</pre>
23033
23034<p>...</p>
23035
23036<pre>reverse_iterator       rbegin();
23037const_reverse_iterator rbegin() const;
23038<ins>const_reverse_iterator crbegin() const;</ins>
23039</pre>
23040
23041<p>...</p>
23042
23043<pre>reverse_iterator       rend();
23044const_reverse_iterator rend() const;
23045<ins>const_reverse_iterator crend() const;</ins>
23046</pre>
23047
23048</blockquote>
23049
23050
23051
23052
23053
23054<hr>
23055<h3><a name="1193"></a>1193. <tt>default_delete</tt> cannot be instantiated with  incomplete types</h3>
23056<p><b>Section:</b> 20.8.14.1 [unique.ptr.dltr] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
23057 <b>Submitter:</b> Daniel Kr�gler <b>Opened:</b> 2009-08-18  <b>Last modified:</b> 2009-08-22</p>
23058<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
23059<p><b>Discussion:</b></p>
23060<p>
23061According to the general rules of 17.6.3.8 [res.on.functions]/2 b 5 the effects
23062are undefined, if an incomplete type is used to instantiate a library template. But neither in
2306320.8.14.1 [unique.ptr.dltr] nor
23064in any other place of the standard such explicit allowance is given.
23065Since this template is intended to be instantiated with incomplete
23066types, this must
23067be fixed.
23068</p>
23069
23070
23071<p><b>Proposed resolution:</b></p>
23072<p>
23073Add two new paragraphs directly to 20.8.14.1 [unique.ptr.dltr] (before
2307420.8.14.1.1 [unique.ptr.dltr.dflt]) with the following
23075content:
23076</p>
23077
23078<blockquote>
23079<p><ins>
23080The class template <tt>default_delete</tt> serves as the default deleter (destruction policy) for
23081the class template <tt>unique_ptr</tt>.
23082</ins></p>
23083
23084<p><ins>
23085The template parameter <tt>T</tt> of <tt>default_delete</tt> may be an incomplete type.
23086</ins></p>
23087</blockquote>
23088
23089
23090
23091
23092
23093<hr>
23094<h3><a name="1194"></a>1194. Unintended <tt>queue</tt> constructor</h3>
23095<p><b>Section:</b> 23.3.5 [container.adaptors] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
23096 <b>Submitter:</b> Howard Hinnant <b>Opened:</b> 2009-08-20  <b>Last modified:</b> 2009-10-20</p>
23097<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#container.adaptors">active issues</a> in [container.adaptors].</p>
23098<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#container.adaptors">issues</a> in [container.adaptors].</p>
23099<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
23100<p><b>Discussion:</b></p>
23101<p>
2310223.3.5.1.1 [queue.defn] has the following <tt>queue</tt> constructor:
23103</p>
23104
23105<blockquote><pre>template &lt;class Alloc&gt; explicit queue(const Alloc&amp;);
23106</pre></blockquote>
23107
23108<p>
23109This will be implemented like so:
23110</p>
23111
23112<blockquote><pre>template &lt;class Alloc&gt; explicit queue(const Alloc&amp; a) : c(a) {}
23113</pre></blockquote>
23114
23115<p>
23116The issue is that <tt>Alloc</tt> can be anything that a container will construct
23117from, for example an <tt>int</tt>.  Is this intended to compile?
23118</p>
23119
23120<blockquote><pre>queue&lt;int&gt; q(5);
23121</pre></blockquote>
23122
23123<p>
23124Before the addition of this constructor, <tt>queue&lt;int&gt;(5)</tt> would not compile.
23125I ask, not because this crashes, but because it is new and appears to be
23126unintended.  We do not want to be in a position of accidently introducing this
23127"feature" in C++0X and later attempting to remove it.
23128</p>
23129
23130<p>
23131I've picked on <tt>queue</tt>.  <tt>priority_queue</tt> and <tt>stack</tt> have
23132the same issue.  Is it useful to create a <tt>priority_queue</tt> of 5
23133identical elements?
23134</p>
23135
23136<p><i>[
23137Daniel, Howard and Pablo collaborated on the proposed wording.
23138]</i></p>
23139
23140
23141<p><i>[
231422009-10 Santa Cruz:
23143]</i></p>
23144
23145
23146<blockquote>
23147Move to Ready.
23148</blockquote>
23149
23150
23151
23152<p><b>Proposed resolution:</b></p>
23153
23154<p><i>[
23155This resolution includes a semi-editorial clean up, giving definitions to members
23156which in some cases weren't defined since C++98.
23157This resolution also offers editorially different wording for <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#976">976</a>,
23158and it also provides wording for <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1196">1196</a>.
23159]</i></p>
23160
23161
23162<p>
23163Change  container.adaptors, p1:
23164</p>
23165
23166<blockquote>
23167The container adaptors each take a <tt>Container</tt> template parameter, and
23168each constructor takes a <tt>Container</tt> reference argument. This container is
23169copied into the <tt>Container</tt> member of each adaptor. If the container takes
23170an allocator, then a compatible allocator may be passed in to the
23171adaptor's constructor. Otherwise, normal copy or move construction is
23172used for the container argument. <del>[<i>Note:</i> it is not necessary for an
23173implementation to distinguish between the one-argument constructor that
23174takes a <tt>Container</tt> and the one- argument constructor that takes an
23175allocator_type. Both forms use their argument to construct an instance
23176of the container. &#8212; <i>end note</i>]</del>
23177</blockquote>
23178
23179<p>
23180Change  queue.defn, p1:
23181</p>
23182
23183<blockquote><pre>template &lt;class T, class Container = deque&lt;T&gt; &gt;
23184class queue {
23185public:
23186  typedef typename Container::value_type      value_type;
23187  typedef typename Container::reference       reference;
23188  typedef typename Container::const_reference const_reference;
23189  typedef typename Container::size_type       size_type;
23190  typedef Container                           container_type;
23191protected:
23192  Container c;
23193
23194public:
23195  explicit queue(const Container&amp;);
23196  explicit queue(Container&amp;&amp; = Container());
23197  queue(queue&amp;&amp; q)<ins>;</ins><del> : c(std::move(q.c)) {}</del>
23198  template &lt;class Alloc&gt; explicit queue(const Alloc&amp;);
23199  template &lt;class Alloc&gt; queue(const Container&amp;, const Alloc&amp;);
23200  template &lt;class Alloc&gt; queue(Container&amp;&amp;, const Alloc&amp;);
23201  template &lt;class Alloc&gt; queue(queue&amp;&amp;, const Alloc&amp;);
23202  queue&amp; operator=(queue&amp;&amp; q)<ins>;</ins><del> { c = std::move(q.c); return *this; }</del>
23203
23204  bool empty() const          { return c.empty(); }
23205  ...
23206};
23207</pre></blockquote>
23208
23209<p>
23210Add a new section after 23.3.5.1.1 [queue.defn], [queue.cons]:
23211</p>
23212
23213<blockquote>
23214<p><b><tt>queue</tt> constructors [queue.cons]</b></p>
23215
23216<pre>explicit queue(const Container&amp; cont);
23217</pre>
23218
23219<blockquote>
23220
23221<p>
23222<i>Effects:</i> Initializes <tt>c</tt> with <tt>cont</tt>.
23223</p>
23224
23225</blockquote>
23226
23227<pre>explicit queue(Container&amp;&amp; cont = Container());
23228</pre>
23229
23230<blockquote>
23231
23232<p>
23233<i>Effects:</i> Initializes <tt>c</tt> with <tt>std::move(cont)</tt>.
23234</p>
23235
23236</blockquote>
23237
23238<pre>queue(queue&amp;&amp; q)
23239</pre>
23240
23241<blockquote>
23242
23243<p>
23244<i>Effects:</i> Initializes <tt>c</tt> with <tt>std::move(q.c)</tt>.
23245</p>
23246
23247</blockquote>
23248
23249<p>
23250For each of the following constructors,
23251if <tt>uses_allocator&lt;container_type, Alloc&gt;::value</tt> is <tt>false</tt>,
23252then the constructor shall not participate in overload resolution.
23253</p>
23254
23255<pre>template &lt;class Alloc&gt; 
23256  explicit queue(const Alloc&amp; a);
23257</pre>
23258
23259<blockquote>
23260
23261<p>
23262<i>Effects:</i> Initializes <tt>c</tt> with <tt>a</tt>.
23263</p>
23264
23265</blockquote>
23266
23267<pre>template &lt;class Alloc&gt; 
23268  queue(const container_type&amp; cont, const Alloc&amp; a);
23269</pre>
23270
23271<blockquote>
23272
23273<p>
23274<i>Effects:</i> Initializes <tt>c</tt> with <tt>cont</tt> as the first
23275argument and <tt>a</tt> as the second argument.
23276</p>
23277
23278</blockquote>
23279
23280<pre>template &lt;class Alloc&gt; 
23281  queue(container_type&amp;&amp; cont, const Alloc&amp; a);
23282</pre>
23283
23284<blockquote>
23285
23286<p>
23287<i>Effects:</i> Initializes <tt>c</tt> with <tt>std::move(cont)</tt> as the
23288first argument and <tt>a</tt> as the second argument.
23289</p>
23290
23291</blockquote>
23292
23293<pre>template &lt;class Alloc&gt; 
23294  queue(queue&amp;&amp; q, const Alloc&amp; a);
23295</pre>
23296
23297<blockquote>
23298
23299<p>
23300<i>Effects:</i> Initializes <tt>c</tt> with <tt>std::move(q.c)</tt> as the
23301first argument and <tt>a</tt> as the second argument.
23302</p>
23303
23304</blockquote>
23305
23306<pre>queue&amp; operator=(queue&amp;&amp; q);
23307</pre>
23308
23309<blockquote>
23310
23311<p>
23312<i>Effects:</i> Assigns <tt>c</tt> with <tt>std::move(q.c)</tt>.
23313</p>
23314
23315<p>
23316<i>Returns:</i> <tt>*this</tt>.
23317</p>
23318
23319</blockquote>
23320
23321
23322
23323</blockquote>
23324
23325<p>
23326Add to 23.3.5.2.1 [priqueue.cons]:
23327</p>
23328
23329<blockquote>
23330
23331<pre>priority_queue(priority_queue&amp;&amp; q);
23332</pre>
23333
23334<blockquote>
23335
23336<p>
23337<i>Effects:</i> Initializes <tt>c</tt> with <tt>std::move(q.c)</tt> and
23338initializes <tt>comp</tt> with <tt>std::move(q.comp)</tt>.
23339</p>
23340
23341</blockquote>
23342
23343<p>
23344For each of the following constructors,
23345if <tt>uses_allocator&lt;container_type, Alloc&gt;::value</tt> is <tt>false</tt>,
23346then the constructor shall not participate in overload resolution.
23347</p>
23348
23349<pre>template &lt;class Alloc&gt;
23350  explicit priority_queue(const Alloc&amp; a);
23351</pre>
23352
23353<blockquote>
23354
23355<p>
23356<i>Effects:</i> Initializes <tt>c</tt> with <tt>a</tt> and value-initializes <tt>comp</tt>.
23357</p>
23358
23359</blockquote>
23360
23361<pre>template &lt;class Alloc&gt;
23362  priority_queue(const Compare&amp; compare, const Alloc&amp; a);
23363</pre>
23364
23365<blockquote>
23366
23367<p>
23368<i>Effects:</i> Initializes <tt>c</tt> with <tt>a</tt> and initializes <tt>comp</tt>
23369with <tt>compare</tt>.
23370</p>
23371
23372</blockquote>
23373
23374<pre>template &lt;class Alloc&gt;
23375  priority_queue(const Compare&amp; compare, const Container&amp; cont, const Alloc&amp; a);
23376</pre>
23377
23378<blockquote>
23379
23380<p>
23381<i>Effects:</i> Initializes <tt>c</tt> with <tt>cont</tt> as the first argument
23382and <tt>a</tt> as the second argument,
23383and initializes <tt>comp</tt> with <tt>compare</tt>.
23384</p>
23385
23386</blockquote>
23387
23388<pre>template &lt;class Alloc&gt;
23389  priority_queue(const Compare&amp; compare, Container&amp;&amp; cont, const Alloc&amp; a);
23390</pre>
23391
23392<blockquote>
23393
23394<p>
23395<i>Effects:</i> Initializes <tt>c</tt> with <tt>std::move(cont)</tt> as 
23396the first argument and <tt>a</tt> as the second argument,
23397and initializes <tt>comp</tt> with <tt>compare</tt>.
23398</p>
23399
23400</blockquote>
23401
23402<pre>template &lt;class Alloc&gt;
23403  priority_queue(priority_queue&amp;&amp; q, const Alloc&amp; a);
23404</pre>
23405
23406<blockquote>
23407
23408<p>
23409<i>Effects:</i> Initializes <tt>c</tt> with <tt>std::move(q.c)</tt> as the
23410first argument and <tt>a</tt> as the second argument, 
23411and initializes <tt>comp</tt> with <tt>std::move(q.comp)</tt>.
23412</p>
23413
23414</blockquote>
23415
23416<pre>priority_queue&amp; operator=(priority_queue&amp;&amp; q);
23417</pre>
23418
23419<blockquote>
23420
23421<p>
23422<i>Effects:</i> Assigns <tt>c</tt> with <tt>std::move(q.c)</tt> and
23423assigns <tt>comp</tt> with <tt>std::move(q.comp)</tt>.
23424</p>
23425
23426<p>
23427<i>Returns:</i> <tt>*this</tt>.
23428</p>
23429
23430</blockquote>
23431
23432</blockquote>
23433
23434
23435
23436
23437<p>
23438Change 23.3.5.3.1 [stack.defn]:
23439</p>
23440
23441<blockquote><pre>template &lt;class T, class Container = deque&lt;T&gt; &gt;
23442class stack {
23443public:
23444  typedef typename Container::value_type      value_type;
23445  typedef typename Container::reference       reference;
23446  typedef typename Container::const_reference const_reference;
23447  typedef typename Container::size_type       size_type;
23448  typedef Container                           container_type;
23449protected:
23450  Container c;
23451
23452public:
23453  explicit stack(const Container&amp;);
23454  explicit stack(Container&amp;&amp; = Container());
23455  <ins>stack(stack&amp;&amp; s);</ins>
23456  template &lt;class Alloc&gt; explicit stack(const Alloc&amp;);
23457  template &lt;class Alloc&gt; stack(const Container&amp;, const Alloc&amp;);
23458  template &lt;class Alloc&gt; stack(Container&amp;&amp;, const Alloc&amp;);
23459  template &lt;class Alloc&gt; stack(stack&amp;&amp;, const Alloc&amp;);
23460  <ins>stack&amp; operator=(stack&amp;&amp; s);</ins>
23461
23462  bool empty() const          { return c.empty(); }
23463  ...
23464};
23465</pre></blockquote>
23466
23467<p>
23468Add a new section after 23.3.5.3.1 [stack.defn], [stack.cons]:
23469</p>
23470
23471<blockquote>
23472<p><b><tt>stack</tt> constructors [stack.cons]</b></p>
23473
23474<pre>stack(stack&amp;&amp; s);
23475</pre>
23476
23477<blockquote>
23478
23479<p>
23480<i>Effects:</i> Initializes <tt>c</tt> with <tt>std::move(s.c)</tt>.
23481</p>
23482
23483</blockquote>
23484
23485<p>
23486For each of the following constructors,
23487if <tt>uses_allocator&lt;container_type, Alloc&gt;::value</tt> is <tt>false</tt>,
23488then the constructor shall not participate in overload resolution.
23489</p>
23490
23491<pre>template &lt;class Alloc&gt; 
23492  explicit stack(const Alloc&amp; a);
23493</pre>
23494
23495<blockquote>
23496
23497<p>
23498<i>Effects:</i> Initializes <tt>c</tt> with <tt>a</tt>.
23499</p>
23500
23501</blockquote>
23502
23503<pre>template &lt;class Alloc&gt; 
23504  stack(const container_type&amp; cont, const Alloc&amp; a);
23505</pre>
23506
23507<blockquote>
23508
23509<p>
23510<i>Effects:</i> Initializes <tt>c</tt> with <tt>cont</tt> as the
23511first argument and <tt>a</tt> as the second argument.
23512</p>
23513
23514</blockquote>
23515
23516<pre>template &lt;class Alloc&gt; 
23517  stack(container_type&amp;&amp; cont, const Alloc&amp; a);
23518</pre>
23519
23520<blockquote>
23521
23522<p>
23523<i>Effects:</i> Initializes <tt>c</tt> with <tt>std::move(cont)</tt> as the
23524first argument and <tt>a</tt> as the second argument.
23525</p>
23526
23527</blockquote>
23528
23529<pre>template &lt;class Alloc&gt; 
23530  stack(stack&amp;&amp; s, const Alloc&amp; a);
23531</pre>
23532
23533<blockquote>
23534
23535<p>
23536<i>Effects:</i> Initializes <tt>c</tt> with <tt>std::move(s.c)</tt> as the
23537first argument and <tt>a</tt> as the second argument.
23538</p>
23539
23540</blockquote>
23541
23542<pre>stack&amp; operator=(stack&amp;&amp; s);
23543</pre>
23544
23545<blockquote>
23546
23547<p>
23548<i>Effects:</i> Assigns <tt>c</tt> with <tt>std::move(s.c)</tt>.
23549</p>
23550
23551<p>
23552<i>Returns:</i> <tt>*this</tt>.
23553</p>
23554
23555</blockquote>
23556
23557</blockquote>
23558
23559
23560
23561
23562
23563
23564<hr>
23565<h3><a name="1197"></a>1197. Can unordered containers have <tt>bucket_count() == 0</tt>?</h3>
23566<p><b>Section:</b> 23.2.5 [unord.req] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
23567 <b>Submitter:</b> Howard Hinnant <b>Opened:</b> 2009-08-24  <b>Last modified:</b> 2009-09-03</p>
23568<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#unord.req">active issues</a> in [unord.req].</p>
23569<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#unord.req">issues</a> in [unord.req].</p>
23570<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
23571<p><b>Discussion:</b></p>
23572<p>
23573Table 97 "Unordered associative container requirements" in
2357423.2.5 [unord.req] says:
23575</p>
23576
23577<blockquote>
23578<table border="1">
23579<caption>Table 97 &#8212; Unordered associative container requirements
23580(in addition to container)</caption>
23581
23582<tbody><tr>
23583<th>Expression</th>
23584<th>Return type</th>
23585<th>Assertion/note pre-/post-condition</th>
23586<th>Complexity</th>
23587</tr>
23588
23589<tr>
23590<td><tt>b.bucket(k)</tt></td>
23591<td><tt>size_type</tt></td>
23592<td>Returns the index of the bucket in which elements with keys 
23593equivalent to <tt>k</tt> would be found, 
23594if any such element existed. 
23595Post: the return value shall be 
23596in the range <tt>[0, 
23597b.bucket_count())</tt>.</td>
23598<td>Constant</td>
23599</tr>
23600
23601</tbody></table>
23602</blockquote>
23603
23604<p>
23605What should <tt>b.bucket(k)</tt> return if <tt>b.bucket_count() == 0</tt>?
23606</p>
23607
23608<p>
23609I believe allowing <tt>b.bucket_count() == 0</tt> is important.  It is a
23610very reasonable post-condition of the default constructor, or of a moved-from
23611container.
23612</p>
23613
23614<p>
23615I can think of several reasonable results from <tt>b.bucket(k)</tt> when
23616<tt>b.bucket_count() == 0</tt>:
23617</p>
23618
23619<ol>
23620<li>
23621Return 0.
23622</li>
23623<li>
23624Return <tt>numeric_limits&lt;size_type&gt;::max()</tt>.
23625</li>
23626<li>
23627Throw a <tt>domain_error</tt>.
23628</li>
23629<li>
23630Precondition: <tt>b.bucket_count() != 0</tt>.
23631</li>
23632</ol>
23633
23634<p><i>[
236352009-08-26 Daniel adds:
23636]</i></p>
23637
23638
23639<blockquote>
23640<p>
23641A forth choice would be to add the pre-condition "<tt>b.bucket_count() != 0</tt>"
23642and thus imply undefined behavior if this is violated.
23643</p>
23644
23645<p><i>[
23646Howard:  I like this option too, added to the list.
23647]</i></p>
23648
23649
23650<p>
23651Further on here my own favorite solution (rationale see below):
23652</p>
23653
23654<p><b>Suggested resolution:</b></p>
23655
23656<p>
23657[Rationale: I suggest to follow choice (1). The main reason is
23658that all associative container functions which take a key argument,
23659are basically free of pre-conditions and non-disrupting, therefore
23660excluding choices (3) and (4). Option (2) seems a bit unexpected
23661to me. It would be more natural, if several similar functions
23662would exist which would also justify the existence of a symbolic
23663constant like npos for this situation. The value 0 is both simple
23664and consistent, it has exactly the same role as a past-the-end
23665iterator value. A typical use-case is:
23666</p>
23667
23668<blockquote><pre>size_type pos = m.bucket(key);
23669if (pos != m.bucket_count()) {
23670 ...
23671} else {
23672 ...
23673}
23674</pre></blockquote>
23675
23676<p>&#8212; end Rationale]</p>
23677
23678<p>
23679- Change Table 97 in 23.2.5 [unord.req] as follows (Row b.bucket(k), Column "Assertion/..."):
23680</p>
23681
23682<blockquote>
23683<table border="1">
23684<caption>Table 97 &#8212; Unordered associative container requirements
23685(in addition to container)</caption>
23686
23687<tbody><tr>
23688<th>Expression</th>
23689<th>Return type</th>
23690<th>Assertion/note pre-/post-condition</th>
23691<th>Complexity</th>
23692</tr>
23693
23694<tr>
23695<td><tt>b.bucket(k)</tt></td>
23696<td><tt>size_type</tt></td>
23697<td>Returns the index of the bucket in which elements with keys 
23698equivalent to <tt>k</tt> would be found, 
23699if any such element existed. 
23700Post: <ins>if b.bucket_count() != 0, </ins>the return value shall be 
23701in the range <tt>[0, 
23702b.bucket_count())</tt><ins>, otherwise 0</ins>.</td>
23703<td>Constant</td>
23704</tr>
23705
23706</tbody></table>
23707</blockquote>
23708
23709</blockquote>
23710
23711
23712
23713<p><b>Proposed resolution:</b></p>
23714<p>
23715</p>
23716
23717
23718
23719
23720
23721<hr>
23722<h3><a name="1198"></a>1198. Container adaptor swap: member or non-member?</h3>
23723<p><b>Section:</b> 23.3.5 [container.adaptors] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
23724 <b>Submitter:</b> Pablo Halpern <b>Opened:</b> 2009-08-26  <b>Last modified:</b> 2009-09-30</p>
23725<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#container.adaptors">active issues</a> in [container.adaptors].</p>
23726<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#container.adaptors">issues</a> in [container.adaptors].</p>
23727<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
23728<p><b>Discussion:</b></p>
23729<p>
23730Under 23.3.5 [container.adaptors] of
23731<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2914.pdf">N2914</a>
23732the member function of <tt>swap</tt> of <tt>queue</tt> and <tt>stack</tt> call:
23733</p>
23734
23735<blockquote><pre>swap(c, q.c);
23736</pre></blockquote>
23737
23738<p>
23739But under 23.3.5 [container.adaptors] of
23740<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2723.pdf">N2723</a>
23741these members are specified to call:
23742</p>
23743
23744<blockquote><pre>c.swap(q.c);
23745</pre></blockquote>
23746
23747<p>
23748Neither draft specifies the semantics of member <tt>swap</tt> for
23749<tt>priority_queue</tt> though it is declared.
23750</p>
23751
23752<p>
23753Although the distinction between member <tt>swap</tt> and non-member
23754<tt>swap</tt> is not important when these adaptors are adapting standard
23755containers, it may be important for user-defined containers.
23756</p>
23757<p>
23758We (Pablo and Howard) feel that
23759it is more likely for a user-defined container to support a namespace scope
23760<tt>swap</tt> than a member <tt>swap</tt>, and therefore these adaptors
23761should use the container's namespace scope <tt>swap</tt>.
23762</p>
23763
23764<p><i>[
237652009-09-30 Daniel adds:
23766]</i></p>
23767
23768
23769<blockquote>
23770The outcome of this issue should be considered with the outcome of <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#774">774</a> both in style and in content (e.g. <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#774">774</a> bullet 9
23771suggests to define the semantic of <tt>void
23772priority_queue::swap(priority_queue&amp;)</tt> in terms of the member
23773<tt>swap</tt> of the container).
23774</blockquote>
23775
23776
23777
23778<p><b>Proposed resolution:</b></p>
23779<p><i>[
23780Changes written with respect to
23781<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2723.pdf">N2723</a>.
23782]</i></p>
23783
23784
23785<p>
23786Change 23.3.5.1.1 [queue.defn]:
23787</p>
23788
23789<blockquote><pre>template &lt;class T, class Container = deque&lt;T&gt; &gt; 
23790class queue {
23791   ...
23792   void swap(queue&amp;<del>&amp;</del> q) { <ins>using std::swap;</ins>
23793                          <del>c.</del>swap(<ins>c, </ins>q.c); }
23794   ...
23795};
23796</pre></blockquote>
23797
23798<p>
23799Change 23.3.5.2 [priority.queue]:
23800</p>
23801
23802<blockquote><pre>template &lt;class T, class Container = vector&lt;T&gt;, 
23803          class Compare = less&lt;typename Container::value_type&gt; &gt; 
23804class priority_queue { 
23805    ...
23806    void swap(priority_queue&amp;<del>&amp;</del> <ins>q</ins>)<del>;</del> <ins>{ using std::swap;</ins>
23807                                     <ins>swap(c, q.c);</ins>
23808                                     <ins>swap(comp, q.comp); }</ins>
23809    ...
23810};
23811</pre></blockquote>
23812
23813<p>
23814Change 23.3.5.3.1 [stack.defn]:
23815</p>
23816
23817<blockquote><pre>template &lt;class T, class Container = deque&lt;T&gt; &gt; 
23818class stack {
23819   ...
23820   void swap(stack&amp;<del>&amp;</del> s) { <ins>using std::swap;</ins>
23821                          <del>c.</del>swap(<ins>c, </ins>s.c); }
23822   ...
23823};
23824</pre></blockquote>
23825
23826
23827
23828
23829
23830
23831<hr>
23832<h3><a name="1199"></a>1199. Missing extended copy constructor in container adaptors</h3>
23833<p><b>Section:</b> 23.3.5 [container.adaptors] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
23834 <b>Submitter:</b> Pablo Halpern <b>Opened:</b> 2009-08-26  <b>Last modified:</b> 2009-08-31</p>
23835<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#container.adaptors">active issues</a> in [container.adaptors].</p>
23836<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#container.adaptors">issues</a> in [container.adaptors].</p>
23837<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
23838<p><b>Discussion:</b></p>
23839<p>
23840<tt>queue</tt> has a constructor:
23841</p>
23842
23843<blockquote><pre>template &lt;class Alloc&gt;
23844  queue(queue&amp;&amp;, const Alloc&amp;);
23845</pre></blockquote>
23846
23847<p>
23848but it is missing a corresponding constructor:
23849</p>
23850
23851<blockquote><pre>template &lt;class Alloc&gt;
23852  queue(const queue&amp;, const Alloc&amp;);
23853</pre></blockquote>
23854
23855<p>
23856The same is true of <tt>priority_queue</tt>, and <tt>stack</tt>.  This
23857"extended copy constructor" is needed for consistency and to ensure that the
23858user of a container adaptor can always specify the allocator for his adaptor.
23859</p>
23860
23861
23862
23863<p><b>Proposed resolution:</b></p>
23864<p><i>[
23865This resolution has been harmonized with the proposed resolution to issue
23866<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1194">1194</a>
23867]</i></p>
23868
23869
23870<p>Change 23.3.5.1.1 [queue.defn], p1:</p>
23871
23872<blockquote><pre>template &lt;class T, class Container = deque&lt;T&gt; &gt;
23873class queue {
23874public:
23875  typedef typename Container::value_type      value_type;
23876  typedef typename Container::reference       reference;
23877  typedef typename Container::const_reference const_reference;
23878  typedef typename Container::size_type       size_type;
23879  typedef Container                           container_type;
23880protected:
23881  Container c;
23882
23883public:
23884  explicit queue(const Container&amp;);
23885  explicit queue(Container&amp;&amp; = Container());
23886  queue(queue&amp;&amp; q);
23887
23888  template &lt;class Alloc&gt; explicit queue(const Alloc&amp;);
23889  template &lt;class Alloc&gt; queue(const Container&amp;, const Alloc&amp;);
23890  template &lt;class Alloc&gt; queue(Container&amp;&amp;, const Alloc&amp;);
23891  <ins>template &lt;class Alloc&gt; queue(const queue&amp;, const Alloc&amp;);</ins>
23892  template &lt;class Alloc&gt; queue(queue&amp;&amp;, const Alloc&amp;);
23893  queue&amp; operator=(queue&amp;&amp; q);
23894
23895  bool empty() const          { return c.empty(); }
23896  ...
23897};
23898</pre></blockquote>
23899
23900<p>
23901To the new section  [queue.cons], introduced
23902in <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1194">1194</a>, add:
23903</p>
23904
23905<blockquote>
23906
23907<pre>template &lt;class Alloc&gt; 
23908  queue(const queue&amp; q, const Alloc&amp; a);
23909</pre>
23910
23911<blockquote><p>
23912<i>Effects:</i> Initializes <tt>c</tt> with <tt>q.c</tt> as the
23913first argument and <tt>a</tt> as the second argument.
23914</p></blockquote>
23915
23916</blockquote>
23917
23918<p>Change 23.3.5.2 [priority.queue] as follows (I've an included an editorial change to
23919  move the poorly-placed move-assignment operator):</p>
23920
23921<blockquote><pre>template &lt;class T, class Container = vector&lt;T&gt;,
23922          class Compare = less&lt;typename Container::value_type&gt; &gt;
23923class priority_queue {
23924public:
23925  typedef typename Container::value_type      value_type;
23926  typedef typename Container::reference       reference;
23927  typedef typename Container::const_reference const_reference;
23928  typedef typename Container::size_type       size_type;
23929  typedef          Container                  container_type;
23930protected:
23931  Container c;
23932  Compare comp;
23933
23934public:
23935  priority_queue(const Compare&amp; x, const Container&amp;);
23936  explicit priority_queue(const Compare&amp; x = Compare(), Container&amp;&amp; = Container());
23937  template &lt;class InputIterator&gt;
23938    priority_queue(InputIterator first, InputIterator last,
23939                   const Compare&amp; x, const Container&amp;);
23940  template &lt;class InputIterator&gt;
23941    priority_queue(InputIterator first, InputIterator last,
23942                   const Compare&amp; x = Compare(), Container&amp;&amp; = Container());
23943  priority_queue(priority_queue&amp;&amp;);
23944  <del>priority_queue&amp; operator=(priority_queue&amp;&amp;);</del>
23945  template &lt;class Alloc&gt; explicit priority_queue(const Alloc&amp;);
23946  template &lt;class Alloc&gt; priority_queue(const Compare&amp;, const Alloc&amp;);
23947  template &lt;class Alloc&gt; priority_queue(const Compare&amp;,
23948                                        const Container&amp;, const Alloc&amp;);
23949  template &lt;class Alloc&gt; priority_queue(const Compare&amp;,
23950                                        Container&amp;&amp;, const Alloc&amp;);
23951  <ins>template &lt;class Alloc&gt; priority_queue(const priority_queue&amp;, const Alloc&amp;);</ins>
23952  template &lt;class Alloc&gt; priority_queue(priority_queue&amp;&amp;, const Alloc&amp;);
23953
23954  <ins>priority_queue&amp; operator=(priority_queue&amp;&amp;);</ins>
23955  ...
23956};
23957</pre></blockquote>
23958
23959<p>
23960Add to 23.3.5.2.1 [priqueue.cons]:
23961</p>
23962
23963<blockquote>
23964
23965<pre>template &lt;class Alloc&gt;
23966  explicit priority_queue(const priority_queue&amp; q, const Alloc&amp; a);
23967</pre>
23968
23969<blockquote><p>
23970<i>Effects:</i> Initializes <tt>c</tt> with <tt>q.c</tt> as the
23971first argument and <tt>a</tt> as the second argument, 
23972and initializes <tt>comp</tt> with <tt>q.comp</tt>.
23973</p></blockquote>
23974
23975</blockquote>
23976
23977<p>
23978Change 23.3.5.3.1 [stack.defn]:
23979</p>
23980
23981<blockquote><pre>template &lt;class T, class Container = deque&lt;T&gt; &gt;
23982class stack {
23983public:
23984  typedef typename Container::value_type      value_type;
23985  typedef typename Container::reference       reference;
23986  typedef typename Container::const_reference const_reference;
23987  typedef typename Container::size_type       size_type;
23988  typedef Container                           container_type;
23989protected:
23990  Container c;
23991
23992public:
23993  explicit stack(const Container&amp;);
23994  explicit stack(Container&amp;&amp; = Container());
23995  stack(stack&amp;&amp; s);
23996
23997  template &lt;class Alloc&gt; explicit stack(const Alloc&amp;);
23998  template &lt;class Alloc&gt; stack(const Container&amp;, const Alloc&amp;);
23999  template &lt;class Alloc&gt; stack(Container&amp;&amp;, const Alloc&amp;);
24000  <ins>template &lt;class Alloc&gt; stack(const stack&amp;, const Alloc&amp;);</ins>
24001  template &lt;class Alloc&gt; stack(stack&amp;&amp;, const Alloc&amp;);
24002  stack&amp; operator=(stack&amp;&amp; s);
24003
24004  bool empty() const          { return c.empty(); }
24005  ...
24006};
24007</pre></blockquote>
24008
24009<p>
24010To the new section  [stack.cons], introduced
24011in <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1194">1194</a>, add:
24012</p>
24013
24014<blockquote>
24015
24016<pre>template &lt;class Alloc&gt; 
24017  stack(const stack&amp; s, const Alloc&amp; a);
24018</pre>
24019
24020<blockquote><p>
24021<i>Effects:</i> Initializes <tt>c</tt> with <tt>s.c</tt> as the
24022first argument and <tt>a</tt> as the second argument.
24023</p></blockquote>
24024</blockquote>
24025
24026
24027
24028
24029
24030
24031<hr>
24032<h3><a name="1200"></a>1200. "surprising" <tt>char_traits&lt;T&gt;::int_type</tt> requirements</h3>
24033<p><b>Section:</b> 21.2.2 [char.traits.typedefs] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
24034 <b>Submitter:</b> Sean Hunt <b>Opened:</b> 2009-09-03  <b>Last modified:</b> 2009-10-28</p>
24035<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#char.traits.typedefs">issues</a> in [char.traits.typedefs].</p>
24036<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
24037<p><b>Discussion:</b></p>
24038<p>
24039The footnote for <tt>int_type</tt> in 21.2.2 [char.traits.typedefs] says that
24040</p>
24041
24042<blockquote>
24043If <tt>eof()</tt>
24044can be held in <tt>char_type</tt> then some iostreams implementations may give
24045surprising results.
24046</blockquote>
24047
24048<p>
24049This implies that <tt>int_type</tt> should be a superset of
24050<tt>char_type</tt>. However, the requirements for <tt>char16_t</tt> and <tt>char32_t</tt> define
24051<tt>int_type</tt> to be equal to <tt>int_least16_t</tt> and <tt>int_least32_t</tt> respectively.
24052<tt>int_least16_t</tt> is likely to be the same size as <tt>char_16_t</tt>, which may lead
24053to surprising behavior, even if <tt>eof()</tt> is not a valid UTF-16 code unit.
24054The standard should not prescribe surprising behavior, especially
24055without saying what it is (it's apparently not undefined, just
24056surprising). The same applies for 32-bit types.
24057</p>
24058
24059<p>
24060I personally recommend that behavior be undefined if <tt>eof()</tt> is a member
24061of <tt>char_type</tt>, and another type be chosen for <tt>int_type</tt> (my personal
24062favorite has always been a <tt>struct {bool eof; char_type c;}</tt>).
24063Alternatively, the exact results of such a situation should be defined,
24064at least so far that I/O could be conducted on these types as long as
24065the code units remain valid. Note that the argument that no one streams
24066<tt>char16_t</tt> or <tt>char32_t</tt> is not really valid as it would be perfectly
24067reasonable to use a <tt>basic_stringstream</tt> in conjunction with UTF character
24068types.
24069</p>
24070
24071<p><i>[
240722009-10-28 Ganesh provides two possible resolutions and expresses a preference
24073for the second:
24074]</i></p>
24075
24076
24077<blockquote>
24078<ol>
24079<li>
24080<p>
24081Replace 21.2.3.2 [char.traits.specializations.char16_t] para 3 with:
24082</p>
24083
24084<blockquote>
24085The member <tt>eof()</tt> shall return <del>an implementation-defined
24086constant that cannot appear as a valid UTF-16 code unit</del>
24087<ins><tt>UINT_LEAST16_MAX</tt> [<i>Note:</i> this value is guaranteed to
24088be a permanently reserved UCS-2 code position if <tt>UINT_LEAST16_MAX ==
240890xFFFF</tt> and it's not a UCS-2 code position otherwise &#8212; <i>end
24090note</i>]</ins>.
24091</blockquote>
24092
24093<p>
24094Replace 21.2.3.3 [char.traits.specializations.char32_t] para 3 with:
24095</p>
24096
24097<blockquote>
24098The member <tt>eof()</tt> shall return <del>an implementation-defined constant that
24099cannot appear as a Unicode code point</del>
24100<ins>
24101<tt>UINT_LEAST32_MAX</tt> [<i>Note:</i> this value is guaranteed to be a
24102permanently reserved UCS-4 code position if <tt>UINT_LEAST32_MAX ==
241030xFFFFFFFF</tt> and it's not a UCS-4 code position otherwise &#8212; <i>end
24104note</i>]</ins>.
24105</blockquote>
24106</li>
24107<li>
24108<p>
24109In 21.2.3.2 [char.traits.specializations.char16_t], in the
24110definition of <tt>char_traits&lt;char16_t&gt;</tt> replace the definition of nested
24111typedef <tt>int_type</tt> with:
24112</p>
24113
24114<blockquote><pre>namespace std {
24115  template&lt;&gt; struct char_traits&lt;char16_t&gt; {
24116    typedef char16_t         char_type;
24117    typedef <del>uint_least16_t</del> <ins>uint_fast16_t</ins> int_type;
24118     ...
24119</pre></blockquote>
24120
24121<p>
24122Replace 21.2.3.2 [char.traits.specializations.char16_t] para 3 with:
24123</p>
24124
24125<blockquote>
24126The member <tt>eof()</tt> shall return <del>an implementation-defined
24127constant that cannot appear as a valid UTF-16 code unit</del>
24128<ins><tt>UINT_FAST16_MAX</tt> [<i>Note:</i> this value is guaranteed to
24129be a permanently reserved UCS-2 code position if <tt>UINT_FAST16_MAX ==
241300xFFFF</tt> and it's not a UCS-2 code position otherwise &#8212; <i>end
24131note</i>]</ins>.
24132</blockquote>
24133
24134<p>
24135In 21.2.3.3 [char.traits.specializations.char32_t], in the
24136definition of <tt>char_traits&lt;char32_t&gt;</tt> replace the definition of nested
24137typedef <tt>int_type</tt> with:
24138</p>
24139
24140<blockquote><pre>namespace std {
24141  template&lt;&gt; struct char_traits&lt;char32_t&gt; {
24142    typedef char32_t         char_type;
24143    typedef <del>uint_least32_t</del> <ins>uint_fast32_t</ins> int_type;
24144     ...
24145</pre></blockquote>
24146
24147<p>
24148Replace 21.2.3.3 [char.traits.specializations.char32_t] para 3 with:
24149</p>
24150
24151<blockquote>
24152The member <tt>eof()</tt> shall return <del>an implementation-defined constant that
24153cannot appear as a Unicode code point</del>
24154<ins>
24155<tt>UINT_FAST32_MAX</tt> [<i>Note:</i> this value is guaranteed to be a
24156permanently reserved UCS-4 code position if <tt>UINT_FAST32_MAX ==
241570xFFFFFFFF</tt> and it's not a UCS-4 code position otherwise &#8212; <i>end
24158note</i>]</ins>.
24159</blockquote>
24160</li>
24161</ol>
24162</blockquote>
24163
24164
24165
24166<p><b>Proposed resolution:</b></p>
24167<p>
24168</p>
24169
24170
24171
24172
24173
24174<hr>
24175<h3><a name="1201"></a>1201. Do we always want to unwrap <tt>ref</tt>-wrappers in <tt>make_tuple</tt></h3>
24176<p><b>Section:</b> 20.5.2.4 [tuple.creation], 20.3.4 [pairs] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#NAD%20Future">Tentatively NAD Future</a>
24177 <b>Submitter:</b> Alisdair Meredith <b>Opened:</b> 2009-09-05  <b>Last modified:</b> 2009-10-26</p>
24178<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Tentatively%20NAD%20Future">Tentatively NAD Future</a> status.</p>
24179<p><b>Discussion:</b></p>
24180<p>
24181Spotting a recent thread on the boost lists regarding collapsing
24182optional representations in <tt>optional&lt;optional&lt;T&gt;&gt;</tt> instances, I wonder if
24183we have some of the same issues with <tt>make_tuple</tt>, and now <tt>make_pair</tt>?
24184</p>
24185
24186<p>
24187Essentially, if my generic code in my own library is handed a
24188<tt>reference_wrapper</tt> by a user, and my library in turn delegates some logic
24189to <tt>make_pair</tt> or <tt>make_tuple</tt>, then I am going to end up with a <tt>pair</tt>/<tt>tuple</tt>
24190holding a real reference rather than the intended reference wrapper.
24191</p>
24192
24193<p>
24194There are two things as a library author I can do at this point:
24195</p>
24196
24197<ol type="i">
24198<li>
24199document my library also has the same reference-wrapper behaviour as
24200<tt>std::make_tuple</tt>
24201</li>
24202<li>
24203roll my own <tt>make_tuple</tt> that does not unwrap rereferences, a lost
24204opportunity to re-use the standard library.
24205</li>
24206</ol>
24207
24208<p>
24209(There may be some metaprogramming approaches my library can use to wrap
24210the <tt>make_tuple</tt> call, but all will be significantly more complex than
24211simply implementing a simplified <tt>make_tuple</tt>.)
24212</p>
24213
24214<p>
24215Now I don't propose we lose this library facility, I think unwrapping
24216references will be the common behaviour.  However, we might want to
24217consider adding another overload that does nothing special with
24218<tt>ref</tt>-wrappers.  Note that we already have a second overload of <tt>make_tuple</tt>
24219in the library, called <tt>tie</tt>.
24220</p>
24221
24222<p><i>[
242232009-09-30 Daniel adds:
24224]</i></p>
24225
24226
24227<blockquote>
24228<p>
24229I suggest to change the currently proposed paragraph for
24230<tt>make_simple_pair</tt>
24231</p>
24232
24233<blockquote><pre>template&lt;typename... Types&gt;
24234  pair&lt;typename decay&lt;Types&gt;::type...&gt; make_simple_pair(Types&amp;&amp;... t);
24235</pre>
24236<blockquote>
24237<p>
24238<del><i>Type requirements:</i> <tt>sizeof...(Types) == 2</tt>.</del>
24239<ins><i>Remarks:</i> The program shall be ill-formed, if
24240<tt>sizeof...(Types) != 2</tt>.</ins>
24241</p>
24242<p>
24243...
24244</p>
24245</blockquote>
24246</blockquote>
24247
24248<p>
24249or alternatively (but with a slightly different semantic):
24250</p>
24251
24252<blockquote>
24253<blockquote>
24254<i>Remarks:</i> If <tt>sizeof...(Types) != 2</tt>, this function shall not
24255participate in overload resolution.
24256</blockquote>
24257</blockquote>
24258
24259<p>
24260to follow a currently introduced style and because the library does
24261not have yet a specific "<i>Type requirements</i>" element. If such thing
24262would be considered as useful this should be done as a separate
24263issue. Given the increasing complexity of either of these wordings
24264it might be preferable to use the normal two-argument-declaration
24265style again in either of the following ways:
24266</p>
24267
24268<ol type="A">
24269<li>
24270<pre>template&lt;class T1, class T2&gt;
24271pair&lt;typename decay&lt;T1&gt;::type, typename decay&lt;T2&gt;::type&gt;
24272make_simple_pair(T1&amp;&amp; t1, T2&amp;&amp; t2);
24273</pre>
24274</li>
24275<li>
24276<pre>template&lt;class T1, class T2&gt;
24277pair&lt;V1, V2&gt; make_simple_pair(T1&amp;&amp; t1, T2&amp;&amp; t2);
24278</pre>
24279<blockquote>
24280Let <tt>V1</tt> be <tt>typename decay&lt;T1&gt;::type</tt> and <tt>V2</tt> be
24281<tt>typename decay&lt;T2&gt;::type</tt>.
24282</blockquote>
24283</li>
24284</ol>
24285
24286</blockquote>
24287
24288<p><i>[
242892009-10 post-Santa Cruz:
24290]</i></p>
24291
24292
24293<blockquote>
24294Mark as Tentatively NAD Future.
24295</blockquote>
24296
24297
24298
24299<p><b>Proposed resolution:</b></p>
24300<p>
24301Add the following function to 20.3.4 [pairs] and signature in
24302appropriate synopses:
24303</p>
24304
24305<blockquote><pre>template&lt;typename... Types&gt;
24306  pair&lt;typename decay&lt;Types&gt;::type...&gt; make_simple_pair(Types&amp;&amp;... t);
24307</pre>
24308<blockquote>
24309<p>
24310<i>Type requirements:</i> <tt>sizeof...(Types) == 2</tt>.
24311</p>
24312<p>
24313<i>Returns:</i> <tt>pair&lt;typename decay&lt;Types&gt;::type...&gt;(std::forward&lt;Types&gt;(t)...)</tt>.
24314</p>
24315</blockquote>
24316</blockquote>
24317
24318<p><i>[
24319Draughting note: I chose a variadic representation similar to <tt>make_tuple</tt>
24320rather than naming both types as it is easier to read through the
24321clutter of metaprogramming this way.  Given there are exactly two
24322elements, the committee may prefer to draught with two explicit template
24323type parameters instead
24324]</i></p>
24325
24326
24327<p>
24328Add the following function to 20.5.2.4 [tuple.creation] and
24329signature in appropriate synopses:
24330</p>
24331
24332<blockquote><pre>template&lt;typename... Types&gt;
24333  tuple&lt;typename decay&lt;Types&gt;::type...&gt; make_simple_tuple(Types&amp;&amp;... t);
24334</pre>
24335<blockquote>
24336<p>
24337<i>Returns:</i> <tt>tuple&lt;typename decay&lt;Types&gt;::type...&gt;(std::forward&lt;Types&gt;(t)...)</tt>.
24338</p>
24339</blockquote>
24340</blockquote>
24341
24342
24343
24344
24345
24346<hr>
24347<h3><a name="1202"></a>1202. <tt>integral_constant</tt> needs a spring clean</h3>
24348<p><b>Section:</b> 20.6.3 [meta.help] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
24349 <b>Submitter:</b> Alisdair Meredith <b>Opened:</b> 2009-09-05  <b>Last modified:</b> 2009-09-06</p>
24350<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#meta.help">issues</a> in [meta.help].</p>
24351<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
24352<p><b>Discussion:</b></p>
24353<p>
24354The specification of <tt>integral_constant</tt> has been inherited
24355essentially unchanged from TR1:
24356</p>
24357
24358<blockquote><pre>template &lt;class T, T v&gt;
24359struct integral_constant {
24360  static const T value = v;
24361  typedef T value_type;
24362  typedef integral_constant&lt;T,v&gt; type;
24363};
24364</pre></blockquote>
24365
24366<p>
24367In light of 0x language changes there are several things we might
24368consider changing, notably the form of specification for value.
24369</p>
24370
24371<p>
24372The current form requires a static data member have storage allocated
24373for it, where we could now implement without this using the new enum
24374syntax:
24375</p>
24376
24377<blockquote><pre>template &lt;class T, T v&gt;
24378struct integral_constant {
24379  <b>enum : T { value = v };</b>
24380  typedef T value_type;
24381  typedef integral_constant type;
24382};
24383</pre></blockquote>
24384
24385<p>
24386The effective difference between these two implementation is:
24387</p>
24388
24389<ol type="i">
24390<li>
24391No requirement to allocate storage for data member (which we hope but do
24392not guarantee compilers strip today)
24393</li>
24394
24395<li>
24396You can no longer take the address of the constant as
24397<tt>&amp;integral_constant&lt;T,v&gt;::value;</tt>
24398</li>
24399</ol>
24400
24401<p>
24402Also note the editorial change to drop the explicit qualification of
24403<tt>integral_constant</tt> in the <tt>typedef type</tt>.  This makes it quite clear we
24404mean the current instantiation, and cannot be mistaken for a recursive
24405metaprogram.
24406</p>
24407
24408<p>
24409Even if we don't mandate this implementation, it would be nice to give
24410vendors freedom under QoI to choose their preferred representation.
24411</p>
24412
24413<p>
24414The other side of this issue is if we choose to retain the static
24415constant form.  In that case we should go further and insist on
24416<tt>constexpr</tt>, much like we did throughout <tt>numeric_limits</tt>:
24417</p>
24418
24419<blockquote><pre>template &lt;class T, T v&gt;
24420struct integral_constant {
24421  static <b>constexpr</b> T value = v;
24422  typedef T value_type;
24423  typedef integral_constant type;
24424};
24425</pre></blockquote>
24426
24427<p>
24428[Footnote] It turns out <tt>constexpr</tt> is part of the Tentatively Ready
24429resolution for <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1019">1019</a>.  I don't want to interfere with that issue, but
24430would like a new issue to consider if the fixed-base enum implementation
24431should be allowed.
24432</p>
24433
24434<p><i>[
244352009-09-05 Daniel adds:
24436]</i></p>
24437
24438
24439<blockquote>
24440<p>
24441I think that the suggested resolution is incomplete and
24442may have some possible unwanted side-effects. To understand
24443why, note that <tt>integral_constant</tt> is <em>completely</em> specified
24444by code in 20.6.3 [meta.help]. While this is usually considered
24445as a good thing, let me give a possible user-defined
24446specialization that would break given the suggested changes:
24447</p>
24448
24449<blockquote><pre>enum NodeColor { Red, Black };
24450
24451std::integral_constant&lt;NodeColor, Red&gt; red;
24452</pre></blockquote>
24453
24454<p>
24455The reason why that breaks is due to the fact that
24456current core language rules does only allow integral
24457types as enum-bases, see 7.2 [dcl.enum]/2.
24458</p>
24459
24460<p>
24461So, I think that we cannot leave the implementation the
24462freedom to decide which way they would like to provide
24463the implementation, because that is easily user-visible
24464(I don't speak of addresses, but of instantiation errors),
24465therefore if applied, this should be either specified or
24466wording must be added that gives a note about this
24467freedom of implementation.
24468</p>
24469
24470<p>
24471Another possible disadvantage seems to me that user-expectations
24472are easy to disappoint if they see a failure
24473of the test
24474</p>
24475
24476<blockquote><pre>assert(typeid(std::integral_constant&lt;int, 0&gt;::value) == typeid(int));
24477</pre></blockquote>
24478
24479<p>
24480or of
24481</p>
24482
24483<blockquote><pre>static_assert(std::is_same&lt;decltype(std::integral_constant&lt;int, 0&gt;::value), const int&gt;::value, "Bad library");
24484</pre></blockquote>
24485
24486</blockquote>
24487
24488
24489
24490<p><b>Proposed resolution:</b></p>
24491
24492
24493
24494
24495
24496<hr>
24497<h3><a name="1204"></a>1204. Global permission to move</h3>
24498<p><b>Section:</b> 17.6.3.9 [res.on.arguments] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
24499 <b>Submitter:</b> Howard Hinnant <b>Opened:</b> 2009-09-12  <b>Last modified:</b> 2009-10-20</p>
24500<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
24501<p><b>Discussion:</b></p>
24502<p>
24503When a library function binds an rvalue reference parameter to an argument, the
24504library must be able to assume that the bound argument is a temporary, and not
24505a moved-from lvalue.  The reason for this is that the library function must be
24506able to modify that argument without concern that such modifications will corrupt
24507the logic of the calling code.  For example:
24508</p>
24509
24510<blockquote><pre>template &lt;class T, class A&gt;
24511void
24512vector&lt;T, A&gt;::push_back(value_type&amp;&amp; v)
24513{
24514    <font color="#c80000">// This function should move from v, potentially modifying</font>
24515    <font color="#c80000">//   the object v is bound to.</font>
24516}
24517</pre></blockquote>
24518
24519<p>
24520If <tt>v</tt> is truly bound to a temporary, then <tt>push_back</tt> has the
24521<em>only</em> reference to this temporary in the entire program.  Thus any
24522modifications will be invisible to the rest of the program.
24523</p>
24524
24525<p>
24526If the client supplies <tt>std::move(x)</tt> to <tt>push_back</tt>, the onus is
24527on the client to ensure that the value of <tt>x</tt> is no longer important to
24528the logic of his program after this statement.  I.e. the client is making a statement
24529that <tt>push_back</tt> may treat <tt>x</tt> as a temporary.
24530</p>
24531
24532<blockquote><em>
24533The above statement is the very foundation upon which move semantics is based.
24534</em></blockquote>
24535
24536<p>
24537The standard is currently lacking a global statement to this effect.  I propose
24538the following addition to 17.6.3.9 [res.on.arguments]:
24539</p>
24540
24541<blockquote>
24542<p>
24543Each of the following statements applies to all arguments to functions
24544defined in the C++ standard library, unless explicitly stated otherwise.
24545</p>
24546<ul>
24547<li>
24548If an argument to a function has an invalid value (such as a value
24549outside the domain of the function, or a pointer invalid for its
24550intended use), the behavior is undefined.
24551</li>
24552<li>
24553If a function argument is described as being an array, the pointer
24554actually passed to the function shall have a value such that all address
24555computations and accesses to objects (that would be valid if the pointer
24556did point to the first element of such an array) are in fact valid.
24557</li>
24558<li><ins>
24559If a function argument binds to an rvalue reference parameter, the C++
24560standard library may assume that this parameter is a unique reference
24561to this argument.  If the parameter is a generic parameter of the
24562form <tt>T&amp;&amp;</tt>, and an lvalue of type <tt>A</tt> is bound,
24563then the binding is considered to be to an lvalue reference
24564(14.9.2.1 [temp.deduct.call]) and thus not covered by this clause.
24565[<i>Note:</i>
24566If a program casts an lvalue to an rvalue while passing that lvalue to
24567a library function (e.g. <tt>move(x)</tt>), then the program is effectively
24568asking the library to treat that lvalue as a temporary.  The library is at
24569liberty to optimize away aliasing checks which might be needed if the argument
24570were an lvalue.
24571&#8212; <i>end note</i>]
24572</ins></li>
24573</ul>
24574
24575</blockquote>
24576
24577<p>
24578Such a global statement will eliminate the need for piecemeal statements such as
2457923.2.1 [container.requirements.general]/13:
24580</p>
24581
24582<blockquote>
24583An object bound to an rvalue reference parameter of a member function of
24584a container shall not be an element of that container; no diagnostic
24585required.
24586</blockquote>
24587
24588<p>
24589Additionally this clarifies that move assignment operators need not perform the
24590traditional <tt>if (this != &amp;rhs)</tt> test commonly found (and needed) in
24591copy assignment operators.
24592</p>
24593
24594<p><i>[
245952009-09-13 Niels adds:
24596]</i></p>
24597
24598
24599<blockquote>
24600Note: This resolution supports the change of 27.9.1.3 [filebuf.assign]/1,
24601proposed by LWG <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#900">900</a>.
24602</blockquote>
24603
24604<p><i>[
246052009 Santa Cruz:
24606]</i></p>
24607
24608
24609<blockquote>
24610Move to Ready.
24611</blockquote>
24612
24613
24614
24615<p><b>Proposed resolution:</b></p>
24616<p>
24617Add a bullet to 17.6.3.9 [res.on.arguments]:
24618</p>
24619
24620<blockquote>
24621<p>
24622Each of the following statements applies to all arguments to functions
24623defined in the C++ standard library, unless explicitly stated otherwise.
24624</p>
24625<ul>
24626<li>
24627If an argument to a function has an invalid value (such as a value
24628outside the domain of the function, or a pointer invalid for its
24629intended use), the behavior is undefined.
24630</li>
24631<li>
24632If a function argument is described as being an array, the pointer
24633actually passed to the function shall have a value such that all address
24634computations and accesses to objects (that would be valid if the pointer
24635did point to the first element of such an array) are in fact valid.
24636</li>
24637<li><ins>
24638If a function argument binds to an rvalue reference parameter, the C++
24639standard library may assume that this parameter is a unique reference
24640to this argument.  If the parameter is a generic parameter of the
24641form <tt>T&amp;&amp;</tt>, and an lvalue of type <tt>A</tt> is bound,
24642then the binding is considered to be to an lvalue reference
24643(14.9.2.1 [temp.deduct.call]) and thus not covered by this clause.
24644[<i>Note:</i>
24645If a program casts an lvalue to an rvalue while passing that lvalue to
24646a library function (e.g. <tt>move(x)</tt>), then the program is effectively
24647asking the library to treat that lvalue as a temporary.  The library is at
24648liberty to optimize away aliasing checks which might be needed if the argument
24649were an lvalue.
24650&#8212; <i>end note</i>]
24651</ins></li>
24652</ul>
24653</blockquote>
24654
24655<p>
24656Delete 23.2.1 [container.requirements.general]/13:
24657</p>
24658
24659<blockquote><del>
24660An object bound to an rvalue reference parameter of a member function of
24661a container shall not be an element of that container; no diagnostic
24662required.
24663</del></blockquote>
24664
24665
24666
24667
24668
24669
24670<hr>
24671<h3><a name="1205"></a>1205. Some algorithms could more clearly document their handling of empty ranges</h3>
24672<p><b>Section:</b> 25 [algorithms] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
24673 <b>Submitter:</b> Alisdair Meredith <b>Opened:</b> 2009-09-13  <b>Last modified:</b> 2009-09-13</p>
24674<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#algorithms">active issues</a> in [algorithms].</p>
24675<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#algorithms">issues</a> in [algorithms].</p>
24676<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
24677<p><b>Discussion:</b></p>
24678<p>
24679There are a number of algorithms whose result might depend on the
24680handling of an empty range.  In some cases the result is not clear,
24681while in others it would help readers to clearly mention the result
24682rather than require some subtle intuition of the supplied wording.
24683</p>
24684
24685<p>
2468625.2.1 [alg.all_of]
24687</p>
24688
24689<blockquote>
24690<i>Returns:</i> <tt>true</tt> if <tt>pred(*i)</tt> is <tt>true</tt> for every
24691iterator <tt>i</tt> in the range <tt>[first,last)</tt>, ...
24692</blockquote>
24693
24694<p>
24695What does this mean if the range is empty?
24696</p>
24697
24698<p>
24699I believe that we intend this to be <tt>true</tt> and suggest a
24700non-normative note to clarify:
24701</p>
24702
24703<p>
24704Add to p1 25.2.1 [alg.all_of]:
24705</p>
24706
24707<blockquote>
24708[<i>Note:</i> Returns <tt>true</tt> if <tt>[first,last)</tt> is empty. 
24709&#8212; <i>end note</i>]
24710</blockquote>
24711
24712<p>
2471325.2.3 [alg.none_of]
24714</p>
24715
24716<blockquote>
24717<i>Returns:</i> <tt>true</tt> if <tt>pred(*i)</tt> is <tt>false</tt> for every
24718iterator <tt>i</tt> in the range <tt>[first,last)</tt>, ...
24719</blockquote>
24720
24721<p>
24722What does this mean if the range empty?
24723</p>
24724
24725<p>
24726I believe that we intend this to be <tt>true</tt> and suggest a
24727non-normative note to clarify:
24728</p>
24729
24730<p>
24731Add to p1 25.2.3 [alg.none_of]:
24732</p>
24733
24734<blockquote>
24735[<i>Note:</i> Returns <tt>true</tt> if <tt>[first,last)</tt> is empty. 
24736&#8212; <i>end note</i>]
24737</blockquote>
24738
24739<p>
2474025.2.2 [alg.any_of]
24741</p>
24742
24743<p>
24744The specification for an empty range is actually fairly clear in this
24745case, but a note wouldn't hurt and would be consistent with proposals
24746for <tt>all_of</tt>/<tt>none_of</tt> algorithms.
24747</p>
24748
24749<p>
24750Add to p1 25.2.2 [alg.any_of]:
24751</p>
24752
24753<blockquote>
24754[<i>Note:</i> Returns <tt>false</tt> if <tt>[first,last)</tt> is empty. 
24755&#8212; <i>end note</i>]
24756</blockquote>
24757
24758<p>
2475925.2.6 [alg.find.end]
24760</p>
24761
24762<p>
24763what does this mean if <tt>[first2,last2)</tt> is empty?
24764</p>
24765
24766<p>
24767I believe the wording suggests the algorithm should return
24768<tt>last1</tt> in this case, but am not 100% sure. Is this in fact the
24769correct result anyway? Surely an empty range should always match and the
24770naive expected result would be <tt>first1</tt>?
24771</p>
24772
24773<p>
24774My proposed wording is a note to clarify the current semantic:
24775</p>
24776
24777<p>
24778Add to p2 25.2.6 [alg.find.end]:
24779</p>
24780
24781<blockquote>
24782[<i>Note:</i> Returns <tt>last1</tt> if <tt>[first2,last2)</tt> is
24783empty. &#8212; <i>end note</i>]
24784</blockquote>
24785
24786<p>
24787I would prefer a normative wording treating empty ranges specially, but
24788do not believe we can change semantics at this point in the process,
24789unless existing implementations actually yield this result:
24790</p>
24791
24792<p>
24793Alternative wording: (NOT a note)
24794</p>
24795<p>
24796Add to p2 25.2.6 [alg.find.end]:
24797</p>
24798<blockquote>
24799Returns <tt>first1</tt> if <tt>[first2,last2)</tt> is empty.
24800</blockquote>
24801
24802<p>
2480325.2.7 [alg.find.first.of]
24804</p>
24805
24806<p>
24807The phrasing seems precise when <tt>[first2, last2)</tt> is empty, but a small
24808note to confirm the reader's understanding might still help.
24809</p>
24810
24811<p>
24812Add to p2 25.2.7 [alg.find.first.of]
24813</p>
24814<blockquote>
24815[<i>Note:</i> Returns <tt>last1</tt> if <tt>[first2,last2)</tt> is
24816empty. &#8212; <i>end note</i>]
24817</blockquote>
24818
24819<p>
2482025.2.12 [alg.search]
24821</p>
24822
24823<p>
24824What is the expected result if <tt>[first2, last2)</tt> is empty?
24825</p>
24826
24827<p>
24828I believe the wording suggests the algorithm should return <tt>last1</tt> in this
24829case, but am not 100% sure. Is this in fact the correct result anyway? 
24830Surely an empty range should always match and the naive expected result
24831would be <tt>first1</tt>?
24832</p>
24833
24834<p>
24835My proposed wording is a note to clarify the current semantic:
24836</p>
24837
24838<p>
24839Add to p2 25.2.12 [alg.search]:
24840</p>
24841
24842<blockquote>
24843[<i>Note:</i> Returns <tt>last1</tt> if <tt>[first2,last2)</tt> is
24844empty. &#8212; <i>end note</i>]
24845</blockquote>
24846
24847<p>
24848Again, I would prefer a normative wording treating empty ranges
24849specially, but do not believe we can change semantics at this point in
24850the process, unless existing implementations actually yield this result:
24851</p>
24852
24853<p>
24854Alternative wording: (NOT a note)
24855</p>
24856<p>
24857Add to p2 25.2.12 [alg.search]:
24858</p>
24859
24860<blockquote>
24861Returns <tt>first1</tt> if <tt>[first2,last2)</tt> is empty.
24862</blockquote>
24863
24864<p>
2486525.3.13 [alg.partitions]
24866</p>
24867
24868<p>
24869Is an empty range partitioned or not?
24870</p>
24871
24872<p>
24873Proposed wording:
24874</p>
24875
24876<p>
24877Add to p1 25.3.13 [alg.partitions]:
24878</p>
24879
24880<blockquote>
24881[<i>Note:</i> Returns <tt>true</tt> if <tt>[first,last)</tt> is empty. 
24882&#8212; <i>end note</i>]
24883</blockquote>
24884
24885<p>
2488625.4.5.1 [includes]
24887</p>
24888
24889<blockquote>
24890<i>Returns:</i> <tt>true</tt> if every element in the range
24891<tt>[first2,last2)</tt> is contained in the range
24892<tt>[first1,last1)</tt>. ...
24893</blockquote>
24894
24895<p>
24896I really don't know what this means if <tt>[first2,last2)</tt> is empty.
24897I could loosely guess that this implies empty ranges always match, and
24898my proposed wording is to clarify exactly that:
24899</p>
24900
24901<p>
24902Add to p1 25.4.5.1 [includes]:
24903</p>
24904
24905<blockquote>
24906[<i>Note:</i> Returns <tt>true</tt> if <tt>[first2,last2)</tt> is empty.
24907&#8212; <i>end note</i>]
24908</blockquote>
24909
24910<p>
2491125.4.6.2 [pop.heap]
24912</p>
24913
24914<p>
24915The effects clause is invalid if the range <tt>[first,last)</tt> is empty, unlike
24916all the other heap alogorithms.  The should be called out in the
24917requirements.
24918</p>
24919
24920<p>
24921Proposed wording:
24922</p>
24923<p>
24924Revise p2 25.4.6.2 [pop.heap]
24925</p>
24926
24927<blockquote>
24928<i>Requires:</i> The range <tt>[first,last)</tt> shall be a valid
24929<ins>non-empty</ins> heap.
24930</blockquote>
24931
24932<p>
24933[Editorial] Reverse order of 25.4.6.2 [pop.heap] p1 and p2.
24934</p>
24935
24936<p>
2493725.4.7 [alg.min.max]
24938</p>
24939
24940<p>
24941<tt>minmax_element</tt> does not clearly specify behaviour for an empty
24942range in the same way that <tt>min_element</tt> and <tt>max_element</tt> do.
24943</p>
24944
24945<p>
24946Add to p31 25.4.7 [alg.min.max]:
24947</p>
24948
24949<blockquote>
24950Returns <tt>make_pair(first, first)</tt> if <tt>first == last</tt>.
24951</blockquote>
24952
24953<p>
2495425.4.8 [alg.lex.comparison]
24955</p>
24956
24957<p>
24958The wording here seems quite clear, especially with the sample algorithm
24959implementation.  A note is recommended purely for consistency with the
24960rest of these issue resolutions:
24961</p>
24962
24963<p>
24964Add to p1 25.4.8 [alg.lex.comparison]:
24965</p>
24966
24967<blockquote>
24968[<i>Note:</i> An empty sequence is lexicographically less than any other
24969non-empty sequence, but not to another empty sequence. &#8212; <i>end note</i>]
24970</blockquote>
24971
24972
24973<p><b>Proposed resolution:</b></p>
24974<p>
24975Add to p1 25.2.1 [alg.all_of]:
24976</p>
24977<blockquote>
24978[<i>Note:</i> Returns <tt>true</tt> if <tt>[first,last)</tt> is empty. 
24979&#8212; <i>end note</i>]
24980</blockquote>
24981
24982<p>
24983Add to p1 25.2.2 [alg.any_of]:
24984</p>
24985<blockquote>
24986[<i>Note:</i> Returns <tt>false</tt> if <tt>[first,last)</tt> is empty. 
24987&#8212; <i>end note</i>]
24988</blockquote>
24989
24990<p>
24991Add to p1 25.2.3 [alg.none_of]:
24992</p>
24993<blockquote>
24994[<i>Note:</i> Returns <tt>true</tt> if <tt>[first,last)</tt> is empty. 
24995&#8212; <i>end note</i>]
24996</blockquote>
24997
24998<p>
24999Add to p2 25.2.6 [alg.find.end]:
25000</p>
25001<blockquote>
25002[<i>Note:</i> Returns <tt>last1</tt> if <tt>[first2,last2)</tt> is
25003empty.  &#8212; <i>end note</i>]
25004</blockquote>
25005
25006<p>
25007Add to p2 25.2.7 [alg.find.first.of]
25008</p>
25009<blockquote>
25010[<i>Note:</i> Returns <tt>last1</tt> if <tt>[first2,last2)</tt> is
25011empty.  &#8212; <i>end note</i>]
25012</blockquote>
25013
25014<p>
25015Add to p2 25.2.12 [alg.search]:
25016</p>
25017<blockquote>
25018[<i>Note:</i> Returns <tt>last1</tt> if <tt>[first2,last2)</tt> is
25019empty.  &#8212; <i>end note</i>]
25020</blockquote>
25021
25022<p>
25023Add to p1 25.3.13 [alg.partitions]:
25024</p>
25025<blockquote>
25026[<i>Note:</i> Returns <tt>true</tt> if <tt>[first,last)</tt> is empty. 
25027&#8212; <i>end note</i>]
25028</blockquote>
25029
25030<p>
25031Add to p1 25.4.5.1 [includes]:
25032</p>
25033<blockquote>
25034[<i>Note:</i> Returns <tt>true</tt> if <tt>[first2,last2)</tt> is empty. 
25035&#8212; <i>end note</i>]
25036</blockquote>
25037
25038<p>
25039Revise p2 25.4.6.2 [pop.heap]
25040</p>
25041<blockquote>
25042Requires: The range <tt>[first,last)</tt> shall be a valid
25043<ins>non-empty</ins> heap.
25044</blockquote>
25045
25046<p>
25047[Editorial] 
25048</p>
25049<blockquote>
25050Reverse order of 25.4.6.2 [pop.heap] p1 and p2.
25051</blockquote>
25052
25053<p>
25054Add to p31 25.4.7 [alg.min.max]:
25055</p>
25056<blockquote>
25057Returns <tt>make_pair(first, first)</tt> if <tt>first == last</tt>.
25058</blockquote>
25059
25060<p>
25061Add to p1 25.4.8 [alg.lex.comparison]:
25062</p>
25063<blockquote>
25064[<i>Note:</i> An empty sequence is lexicographically less than any other
25065non-empty sequence, but not less than another empty sequence. &#8212;
25066<i>end note</i>]
25067</blockquote>
25068
25069
25070
25071
25072
25073
25074<hr>
25075<h3><a name="1206"></a>1206. Incorrect requires for <tt>move_backward</tt> and <tt>copy_backward</tt></h3>
25076<p><b>Section:</b> 25.3.2 [alg.move] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
25077 <b>Submitter:</b> Howard Hinnant <b>Opened:</b> 2009-09-13  <b>Last modified:</b> 2009-09-13</p>
25078<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
25079<p><b>Discussion:</b></p>
25080<p>
2508125.3.2 [alg.move], p6 says:
25082</p>
25083
25084<blockquote>
25085<pre>template&lt;class BidirectionalIterator1, class BidirectionalIterator2&gt;
25086  BidirectionalIterator2
25087    move_backward(BidirectionalIterator1 first,
25088                  BidirectionalIterator1 last,
25089                  BidirectionalIterator2 result);
25090</pre>
25091<blockquote>
25092<p>...</p>
25093<p>
25094<i>Requires:</i> <tt>result</tt> shall not be in the range
25095<tt>[first,last)</tt>.
25096</p>
25097</blockquote>
25098</blockquote>
25099
25100<p>
25101This is essentially an "off-by-one" error.
25102</p>
25103
25104<p>
25105When <tt>result == last</tt>, which
25106<em>is</em> allowed by this specification, then the range <tt>[first, last)</tt>
25107is being move assigned into the range <tt>[first, last)</tt>.  The <tt>move</tt>
25108(forward) algorithm doesn't allow self move assignment, and neither should
25109<tt>move_backward</tt>.  So <tt>last</tt> should be included in the range which
25110<tt>result</tt> can not be in.
25111</p>
25112
25113<p>
25114Conversely, when <tt>result == first</tt>, which <em>is not</em> allowed by this
25115specification, then the range <tt>[first, last)</tt>
25116is being move assigned into the range <tt>[first - (last-first), first)</tt>.
25117I.e. into a <em>non-overlapping</em> range.  Therefore <tt>first</tt> should
25118not be included in the range which <tt>result</tt> can not be in.
25119</p>
25120
25121<p>
25122The same argument applies to <tt>copy_backward</tt> though copy assigning elements
25123to themselves (<tt>result == last</tt>) should be harmless (though is disallowed
25124by <tt>copy</tt>).
25125</p>
25126
25127
25128
25129<p><b>Proposed resolution:</b></p>
25130<p>
25131Change 25.3.2 [alg.move], p6:
25132</p>
25133
25134<blockquote>
25135<pre>template&lt;class BidirectionalIterator1, class BidirectionalIterator2&gt;
25136  BidirectionalIterator2
25137    move_backward(BidirectionalIterator1 first,
25138                  BidirectionalIterator1 last,
25139                  BidirectionalIterator2 result);
25140</pre>
25141<blockquote>
25142<p>...</p>
25143<p>
25144<i>Requires:</i> <tt>result</tt> shall not be in the range
25145<tt><del>[</del><ins>(</ins>first,last<ins>]</ins><del>)</del></tt>.
25146</p>
25147</blockquote>
25148</blockquote>
25149
25150<p>
25151Change 25.3.1 [alg.copy], p13:
25152</p>
25153
25154<blockquote>
25155<pre>template&lt;class BidirectionalIterator1, class BidirectionalIterator2&gt;
25156  BidirectionalIterator2
25157    copy_backward(BidirectionalIterator1 first,
25158                  BidirectionalIterator1 last,
25159                  BidirectionalIterator2 result);
25160</pre>
25161<blockquote>
25162<p>...</p>
25163<p>
25164<i>Requires:</i> <tt>result</tt> shall not be in the range
25165<tt><del>[</del><ins>(</ins>first,last<ins>]</ins><del>)</del></tt>.
25166</p>
25167</blockquote>
25168</blockquote>
25169
25170
25171
25172
25173
25174<hr>
25175<h3><a name="1207"></a>1207. Underspecified std::list operations?</h3>
25176<p><b>Section:</b> 23.3.4.4 [list.ops] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
25177 <b>Submitter:</b> Lo�c Joly <b>Opened:</b> 2009-09-13  <b>Last modified:</b> 2009-09-19</p>
25178<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#list.ops">active issues</a> in [list.ops].</p>
25179<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#list.ops">issues</a> in [list.ops].</p>
25180<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
25181<p><b>Discussion:</b></p>
25182<p>
25183It looks to me like some operations of <tt>std::list</tt>
25184(<tt>sort</tt>, <tt>reverse</tt>, <tt>remove</tt>, <tt>unique</tt> &amp;
25185<tt>merge</tt>) do not specify the validity of iterators, pointers &amp;
25186references to elements of the list after those operations. Is it implied
25187by some other text in the standard?
25188</p>
25189
25190<p>
25191I believe <tt>sort</tt> &amp; <tt>reverse</tt> do not invalidating
25192anything, <tt>remove</tt> &amp; <tt>unique</tt> only invalidates what
25193refers to erased elements, <tt>merge</tt> does not invalidate anything
25194(with the same precision as <tt>splice</tt> for elements who changed of
25195container). Are those assumptions correct ?
25196</p>
25197
25198
25199<p><b>Proposed resolution:</b></p>
25200
25201
25202
25203
25204
25205<hr>
25206<h3><a name="1208"></a>1208. valarray initializer_list constructor has incorrect effects</h3>
25207<p><b>Section:</b> 26.6.2.1 [valarray.cons] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Tentatively Ready</a>
25208 <b>Submitter:</b> Howard Hinnant <b>Opened:</b> 2009-09-23  <b>Last modified:</b> 2009-10-29</p>
25209<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#valarray.cons">issues</a> in [valarray.cons].</p>
25210<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Tentatively%20Ready">Tentatively Ready</a> status.</p>
25211<p><b>Discussion:</b></p>
25212<p>
2521326.6.2.1 [valarray.cons] says:
25214</p>
25215
25216<blockquote>
25217<pre>valarray(initializer_list&lt;T&gt; il);
25218</pre>
25219<blockquote>
25220<i>Effects:</i> Same as <tt>valarray(il.begin(), il.end())</tt>.
25221</blockquote>
25222</blockquote>
25223
25224<p>
25225But there is no <tt>valarray</tt> constructor taking two <tt>const T*</tt>.
25226</p>
25227
25228<p><i>[
252292009-10-29 Howard:
25230]</i></p>
25231
25232
25233<blockquote>
25234Moved to Tentatively Ready after 6 positive votes on c++std-lib.
25235</blockquote>
25236
25237
25238<p><b>Proposed resolution:</b></p>
25239<p>
25240Change 26.6.2.1 [valarray.cons]:
25241</p>
25242
25243<blockquote>
25244<pre>valarray(initializer_list&lt;T&gt; il);
25245</pre>
25246<blockquote>
25247<i>Effects:</i> Same as <tt>valarray(il.begin(), il.<del>end</del><ins>size</ins>())</tt>.
25248</blockquote>
25249</blockquote>
25250
25251
25252
25253
25254
25255<hr>
25256<h3><a name="1209"></a>1209. match_results should be moveable</h3>
25257<p><b>Section:</b> 28.10.1 [re.results.const] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
25258 <b>Submitter:</b> Stephan T. Lavavej <b>Opened:</b> 2009-09-15  <b>Last modified:</b> 2009-09-21</p>
25259<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
25260<p><b>Discussion:</b></p>
25261<p>
25262In Working Draft
25263<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2914.pdf">N2914</a>,
25264<tt>match_results</tt> lacks a move constructor and move
25265assignment operator. Because it owns dynamically allocated memory, it
25266should be moveable.
25267</p>
25268
25269<p>
25270As far as I can tell, this isn't tracked by an active issue yet; Library
25271Issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#723">723</a> doesn't talk about <tt>match_results</tt>.
25272</p>
25273
25274<p><i>[
252752009-09-21 Daniel provided wording.
25276]</i></p>
25277
25278
25279
25280<p><b>Proposed resolution:</b></p>
25281<ol>
25282<li>
25283<p>
25284Add the following member declarations to 28.10 [re.results]/3:
25285</p>
25286
25287<blockquote><pre>// 28.10.1, construct/copy/destroy:
25288explicit match_results(const Allocator&amp; a = Allocator());
25289match_results(const match_results&amp; m);
25290<ins>match_results(match_results&amp;&amp; m);</ins>
25291match_results&amp; operator=(const match_results&amp; m);
25292<ins>match_results&amp; operator=(match_results&amp;&amp; m);</ins>
25293~match_results();
25294</pre></blockquote>
25295</li>
25296
25297<li>
25298<p>
25299Add the following new prototype descriptions to 28.10.1 [re.results.const]
25300using the table numbering of
25301<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2723.pdf">N2723</a>:
25302</p>
25303
25304<blockquote>
25305<pre>match_results(const match_results&amp; m);
25306</pre>
25307
25308<blockquote>
253094 <i>Effects:</i> Constructs an object of class <tt>match_results</tt>, as a
25310copy of <tt>m</tt>.
25311</blockquote>
25312
25313<pre><ins>match_results(match_results&amp;&amp; m);</ins>
25314</pre>
25315
25316<blockquote>
25317<p>
25318<ins>5 <i>Effects:</i> Move-constructs an object of class <tt>match_results</tt>
25319from <tt>m</tt> satisfying the same postconditions as Table 132. Additionally
25320the stored <tt>Allocator</tt> value is move constructed from <tt>m.get_allocator()</tt>.
25321After the initialization of <tt>*this</tt> sets <tt>m</tt> to an unspecified but valid
25322state.</ins>
25323</p>
25324
25325<p>
25326<ins>6 <i>Throws:</i> Nothing if the allocator's move constructor throws nothing.</ins>
25327</p>
25328</blockquote>
25329
25330<pre>match_results&amp; operator=(const match_results&amp; m);
25331</pre>
25332
25333<blockquote>
253347 <i>Effects:</i> Assigns <tt>m</tt> to <tt>*this</tt>. The postconditions of this function are
25335indicated in Table 132.
25336</blockquote>
25337
25338<pre><ins>match_results&amp; operator=(match_results&amp;&amp; m);</ins>
25339</pre>
25340
25341<blockquote>
25342<p>
25343<ins>8 <i>Effects:</i> Move-assigns <tt>m</tt> to <tt>*this</tt>. The postconditions of this
25344function are indicated in Table 132. After the assignment, <tt>m</tt> is in
25345a valid but unspecified state.</ins>
25346</p>
25347
25348<p>
25349<ins>9 <i>Throws:</i> Nothing.</ins>
25350</p>
25351</blockquote>
25352</blockquote>
25353</li>
25354
25355</ol>
25356
25357
25358
25359
25360
25361<hr>
25362<h3><a name="1210"></a>1210. iterator reachability should not require a container</h3>
25363<p><b>Section:</b> 24.2 [iterator.requirements] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
25364 <b>Submitter:</b> Alisdair Meredith <b>Opened:</b> 2009-09-18  <b>Last modified:</b> 2009-09-19</p>
25365<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#iterator.requirements">active issues</a> in [iterator.requirements].</p>
25366<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#iterator.requirements">issues</a> in [iterator.requirements].</p>
25367<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
25368<p><b>Discussion:</b></p>
25369<p>
25370p6 Iterator requirements 24.2 [iterator.requirements]
25371</p>
25372
25373<blockquote>
25374An iterator <tt>j</tt> is called reachable from an iterator <tt>i</tt> if and only if
25375there is a finite sequence of applications of the expression <tt>++i</tt> that
25376makes <tt>i == j</tt>. If <tt>j</tt> is reachable from <tt>i</tt>, they refer to the same
25377container.
25378</blockquote>
25379
25380<p>
25381A good example would be stream iterators, which do not refer to a
25382container.  Typically, the end iterator from a range of stream iterators
25383will compare equal for many such ranges.  I suggest striking the second
25384sentence.
25385</p>
25386
25387<p>
25388An alternative wording might be:
25389</p>
25390
25391<blockquote>
25392If <tt>j</tt> is reachable from <tt>i</tt>, and both <tt>i</tt> and
25393<tt>j</tt> are dereferencable iterators, then they refer to the same
25394range.
25395</blockquote>
25396
25397
25398<p><b>Proposed resolution:</b></p>
25399<p>
25400Change 24.2 [iterator.requirements], p6:
25401</p>
25402
25403<blockquote>
25404An iterator <tt>j</tt> is called <i>reachable</i> from an iterator
25405<tt>i</tt> if and only if there is a finite sequence of applications of
25406the expression <tt>++i</tt> that makes <tt>i == j</tt>. <del>If
25407<tt>j</tt> is reachable from <tt>i</tt>, they refer to the same
25408container.</del>
25409</blockquote>
25410
25411
25412
25413
25414
25415<hr>
25416<h3><a name="1211"></a>1211. move iterators should be restricted as input iterators</h3>
25417<p><b>Section:</b> 24.5.3.1 [move.iterator] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
25418 <b>Submitter:</b> Alisdair Meredith <b>Opened:</b> 2009-09-18  <b>Last modified:</b> 2009-10-26</p>
25419<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#move.iterator">issues</a> in [move.iterator].</p>
25420<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
25421<p><b>Discussion:</b></p>
25422<p>
25423I contend that while we can support both bidirectional and random access
25424traversal, the category of a move iterator should never be better than
25425<tt>input_iterator_tag</tt>.
25426</p>
25427
25428<p>
25429The contentious point is that you cannot truly have a multipass property
25430when values are moved from a range.  This is contentious if you view a
25431moved-from object as still holding a valid value within the range.  
25432</p>
25433
25434<p>
25435The second reason comes from the Forward Iterator requirements table:
25436</p>
25437
25438<blockquote>
25439<p>
25440Forward iterators 24.2.3 [forward.iterators]
25441</p>
25442
25443<p>
25444Table 102 -- Forward iterator requirements
25445</p>
25446
25447<blockquote>
25448For expression <tt>*a</tt> the return type is:
25449"<tt>T&amp;</tt> if <tt>X</tt> is mutable, otherwise <tt>const T&amp;</tt>"
25450</blockquote>
25451</blockquote>
25452
25453<p>
25454There is a similar constraint on <tt>a-&gt;m</tt>.
25455</p>
25456
25457<p>
25458There is no support for rvalue references, nor do I believe their should
25459be.  Again, opinions may vary but either this table or the definition of
25460<tt>move_iterator</tt> need updating.
25461</p>
25462
25463<p>
25464Note: this requirement probably need updating anyway if we wish to
25465support proxy iterators but I am waiting to see a new working paper
25466before filing that issue.
25467</p>
25468
25469<p><i>[
254702009-10 post-Santa Cruz:
25471]</i></p>
25472
25473
25474<blockquote>
25475Move to Open. Howard to put his rationale mentioned above into the issue
25476as a note.
25477</blockquote>
25478
25479<p><i>[
254802009-10-26 Howard adds:
25481]</i></p>
25482
25483
25484<blockquote>
25485<p>
25486<tt>vector::insert(pos, iter, iter)</tt> is significantly more effcient when
25487<tt>iter</tt> is a random access iterator, as compared to when it is an
25488input iterator.
25489</p>
25490
25491<p>
25492When <tt>iter</tt> is an input iterator, the best algorithm
25493is to append the inserted range to the end of the <tt>vector</tt> using
25494<tt>push_back</tt>.  This may involve several reallocations before the input
25495range is exhausted.  After the append, then one can use <tt>std::rotate</tt>
25496to place the inserted range into the correct position in the vector.
25497</p>
25498
25499<p>
25500But when <tt>iter</tt> is a random access iterator, the best algorithm
25501is to first compute the size of the range to be inserted (<tt>last - first</tt>),
25502do a buffer reallocation if necessary, scoot existing elements in the <tt>vector</tt>
25503down to make the "hole", and then insert the new elements directly to their correct
25504place.
25505</p>
25506
25507<blockquote><b>
25508The insert-with-random-access-iterators algorithm is considerably more efficient
25509than the insert-with-input-iterators algorithm
25510</b></blockquote>
25511
25512<p>
25513Now consider:
25514</p>
25515
25516<blockquote><pre>vector&lt;A&gt; v;
25517<font color="#c80000">//  ... build up a large vector of A ...</font>
25518vector&lt;A&gt; temp;
25519<font color="#c80000">//  ... build up a large temporary vector of A to later be inserted ...</font>
25520typedef move_iterator&lt;vector&lt;A&gt;::iterator&gt; MI;
25521<font color="#c80000">//  Now insert the temporary elements:</font>
25522v.insert(v.begin() + N, MI(temp.begin()), MI(temp.end()));
25523</pre></blockquote>
25524
25525<p>
25526A major motivation for using <tt>move_iterator</tt> in the above example is the
25527expectation that <tt>A</tt> is cheap to move but expensive to copy.  I.e. the
25528customer is looking for <em>high performance</em>.  If we allow <tt>vector::insert</tt>
25529to subtract two <tt>MI</tt>'s to get the distance between them, the customer enjoys
25530substantially better performance, compared to if we say that <tt>vector::insert</tt>
25531can not subtract two <tt>MI</tt>'s.
25532</p>
25533
25534<p>
25535I can find no rationale for not giving this performance boost to our customers.
25536Therefore I am strongly against restricting <tt>move_iterator</tt> to the
25537<tt>input_iterator_tag</tt> category.
25538</p>
25539
25540<p>
25541I believe that the requirement that forward
25542iterators have a dereference that returns an lvalue reference to cause unacceptable
25543pessimization.  For example <tt>vector&lt;bool&gt;::iterator</tt> also does not return
25544a <tt>bool&amp;</tt> on dereference.  Yet I am not aware of a single vendor that
25545is willing to ship <tt>vector&lt;bool&gt;::iterator</tt> as an input iterator.
25546Everyone classifies it as a random access iterator.  Not only does this not
25547cause any problems, it prevents significant performance problems.
25548</p>
25549
25550</blockquote>
25551
25552
25553
25554<p><b>Proposed resolution:</b></p>
25555<p>
25556Class template move_iterator 24.5.3.1 [move.iterator]
25557</p>
25558
25559<blockquote><pre>namespace std {
25560template &lt;class Iterator&gt;
25561class move_iterator {
25562public:
25563 ...
25564 typedef <del>typename iterator_traits&lt;Iterator&gt;::iterator_category</del> <ins>input_iterator_tag</ins> iterator_category;
25565</pre></blockquote>
25566
25567
25568
25569
25570
25571<hr>
25572<h3><a name="1212"></a>1212. result of post-increment/decrement operator</h3>
25573<p><b>Section:</b> 24.2 [iterator.requirements] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
25574 <b>Submitter:</b> Alisdair Meredith <b>Opened:</b> 2009-09-18  <b>Last modified:</b> 2009-09-19</p>
25575<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#iterator.requirements">active issues</a> in [iterator.requirements].</p>
25576<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#iterator.requirements">issues</a> in [iterator.requirements].</p>
25577<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
25578<p><b>Discussion:</b></p>
25579<p>Forward iterator and bidirectional iterator place different
25580requirements on the result of post-increment/decrement operator. The
25581same form should be used in each case.
25582</p>
25583
25584<p>
25585Merging row from:
25586</p>
25587
25588<blockquote><pre>Table 102 -- Forward iterator requirements
25589Table 103 -- Bidirectional iterator requirements
25590
25591    r++ : convertible to const X&amp;
25592    r-- : convertible to const X&amp;
25593    
25594    *r++ : T&amp; if X is mutable, otherwise const T&amp;
25595    *r-- : convertible to T
25596</pre></blockquote>
25597
25598
25599<p><b>Proposed resolution:</b></p>
25600
25601
25602
25603
25604
25605<hr>
25606<h3><a name="1213"></a>1213. Meaning of valid and singular iterator underspecified</h3>
25607<p><b>Section:</b> 24.2 [iterator.requirements] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
25608 <b>Submitter:</b> Daniel Kr�gler <b>Opened:</b> 2009-09-19  <b>Last modified:</b> 2009-09-19</p>
25609<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#iterator.requirements">active issues</a> in [iterator.requirements].</p>
25610<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#iterator.requirements">issues</a> in [iterator.requirements].</p>
25611<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
25612<p><b>Discussion:</b></p>
25613<p>
25614The terms <em>valid</em> iterator and <em>singular</em> aren't
25615properly defined. The fuzziness of those terms became even worse
25616after the resolution of <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#208">208</a> (including further updates by <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#278">278</a>). In
2561724.2 [iterator.requirements] as of
25618<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2723.pdf">N2723</a>
25619the standard says now:
25620</p>
25621
25622<blockquote>
25623<p>
256245 - These values are called past-the-end values. Values of an iterator <tt>i</tt> for
25625which the expression <tt>*i</tt> is defined are called dereferenceable. The library
25626never assumes that past-the-end values are dereferenceable. Iterators
25627can also have singular values that are not associated with any
25628container. [...] Results of most expressions are undefined for singular
25629values; the only exceptions are destroying an iterator that holds a
25630singular value and the assignment of a non-singular value to an iterator
25631that holds a singular value. [...] Dereferenceable values are always
25632non-singular.
25633</p>
25634
25635<p>
2563610 - An invalid iterator is an iterator that may be singular.
25637</p>
25638</blockquote>
25639
25640<p>
25641First, issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#208">208</a> intentionally removed the earlier constraint that past-the-end
25642values are always non-singular. The reason for this was to support null
25643pointers as past-the-end iterators of e.g. empty sequences. But there
25644seem to exist different views on what a singular (iterator) value is. E.g.
25645according to the <a href="http://www.sgi.com/tech/stl/trivial.html">SGI definition</a>
25646a null pointer is <em>not</em> a singular value:
25647</p>
25648
25649<blockquote>
25650Dereferenceable iterators are always nonsingular, but the converse is
25651not true.
25652For example, a null pointer is nonsingular (there are well defined operations
25653involving null pointers) even thought it is not dereferenceable.
25654</blockquote>
25655
25656<p>
25657and <a href="http://www.sgi.com/tech/stl/InputIterator.html">proceeds</a>:
25658</p>
25659
25660<blockquote>
25661An iterator is valid if it is dereferenceable or past-the-end.
25662</blockquote>
25663
25664<p>
25665Even if the standard prefers a different meaning of singular here, the
25666change was
25667incomplete, because by restricting feasible expressions of singular
25668iterators to
25669destruction and assignment isn't sufficient for a past-the-end
25670iterator: Of-course
25671it must still be equality-comparable and in general be a readable value.
25672</p>
25673
25674<p>
25675Second, the standard doesn't clearly say whether a past-the-end value is
25676a valid iterator or not. E.g. 20.8.13 [specialized.algorithms]/1 says:
25677</p>
25678
25679<blockquote>
25680In all of the following algorithms, the formal template parameter
25681<tt>ForwardIterator</tt>
25682is required to satisfy the requirements of a forward iterator (24.1.3)
25683[..], and is
25684required to have the property that no exceptions are thrown from [..], or
25685dereference of valid iterators.
25686</blockquote>
25687
25688<p>
25689The standard should make better clear what "singular pointer" and "valid
25690iterator" means. The fact that the meaning of a valid <em>value</em>
25691has a core language meaning doesn't imply that for an iterator concept
25692the term "valid iterator" has the same meaning.
25693</p>
25694
25695<p>
25696Let me add a final example: In X [allocator.concepts.members] of
25697<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2914.pdf">N2914</a>
25698we find:
25699</p>
25700
25701<blockquote><pre>pointer X::allocate(size_type n);
25702</pre>
25703
25704<blockquote>
2570511 <i>Returns:</i> a pointer to the allocated memory. [<i>Note:</i> if <tt>n == 0</tt>, the return
25706value is unspecified. &#8212;<i>end note</i>]
25707</blockquote>
25708
25709<p>
25710[..]
25711</p>
25712
25713<pre>void X::deallocate(pointer p, size_type n);
25714</pre>
25715
25716<blockquote>
25717<i>Preconditions:</i> <tt>p</tt> shall be a non-singular pointer value obtained from a call
25718to <tt>allocate()</tt> on this allocator or one that compares equal to it.
25719</blockquote>
25720</blockquote>
25721
25722<p>
25723If singular pointer value would include null pointers this make the
25724preconditions
25725unclear if the pointer value is a result of <tt>allocate(0)</tt>: Since the return value
25726is unspecified, it could be a null pointer. Does that mean that programmers
25727need to check the pointer value for a null value before calling deallocate?
25728</p>
25729
25730
25731<p><b>Proposed resolution:</b></p>
25732
25733
25734
25735
25736
25737<hr>
25738<h3><a name="1214"></a>1214. Insufficient/inconsistent key immutability requirements for  associative containers</h3>
25739<p><b>Section:</b> 23.2.4 [associative.reqmts] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
25740 <b>Submitter:</b> Daniel Kr�gler <b>Opened:</b> 2009-09-20  <b>Last modified:</b> 2009-09-20</p>
25741<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#associative.reqmts">active issues</a> in [associative.reqmts].</p>
25742<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#associative.reqmts">issues</a> in [associative.reqmts].</p>
25743<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
25744<p><b>Discussion:</b></p>
25745<p>
25746Scott Meyers' mentions on a recent posting on <a href="http://groups.google.de/group/comp.std.c++/msg/6f9160fc428bcbea">c.s.c++</a>
25747some arguments that point to an incomplete resolution
25748of <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#103">103</a> and to an inconsistency of requirements on keys in ordered and
25749unordered associative
25750containers:
25751</p>
25752
25753<blockquote>
25754<p>
257551) <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#103">103</a> introduced the term immutable without defining it in a unique manner in
2575623.2.4 [associative.reqmts]/5:
25757</p>
25758
25759<blockquote>
25760[..] Keys in an associative container are immutable.
25761</blockquote>
25762
25763<p>
25764According to conventional dictionaries immutable is an unconditional way of
25765saying that something cannot be changed. So without any further explicit
25766allowance a user <em>always</em> runs into undefined behavior if (s)he attempts
25767to modify such a key. IMO this was not the intend of the committee to resolve
25768<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#103">103</a> in that way because the comments suggest an interpretation that
25769should give any user the freedom to modify the key in an <em>explicit</em> way
25770<em>provided</em> it would not affect the sort order in that container.
25771</p>
25772
25773<p>
257742) Another observation was that surprisingly no similar 'safety guards'
25775exists against unintentional key changes for the unordered associative
25776containers, specifically there is no such requirement as in
2577723.2.4 [associative.reqmts]/6 that "both <tt>iterator</tt> and <tt>const_iterator</tt> are constant
25778iterators". But the need for such protection against unintentional
25779changes as well as the constraints in which manner any explicit
25780changes may be performed are both missing and necessary, because
25781such changes could potentially change the <em>equivalence</em> of keys that
25782is measured by the <tt>hasher</tt> and <tt>key_equal</tt>.
25783</p>
25784
25785<p>
25786I suggest to fix the unconditional wording involved with "immutable keys"
25787by at least adding a hint for the reader that users <em>may</em> perform such
25788changes in an explicit manner <em>and</em> to perform similar wording changes
25789as <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#103">103</a> did for the ordered associative containers also for the unordered
25790containers.
25791</p>
25792</blockquote>
25793
25794
25795<p><b>Proposed resolution:</b></p>
25796
25797
25798
25799
25800
25801<hr>
25802<h3><a name="1215"></a>1215. <tt>list::merge</tt> with unequal allocators</h3>
25803<p><b>Section:</b> 23.3.4.4 [list.ops] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
25804 <b>Submitter:</b> Pablo Halpern <b>Opened:</b> 2009-09-24  <b>Last modified:</b> 2009-09-24</p>
25805<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#list.ops">active issues</a> in [list.ops].</p>
25806<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#list.ops">issues</a> in [list.ops].</p>
25807<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
25808<p><b>Discussion:</b></p>
25809<p>
25810In Bellevue (I think), we passed
25811<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2525.pdf">N2525</a>,
25812which, among other things, specifies that the behavior of
25813<tt>list::splice</tt> is undefined if the allocators of the two lists
25814being spliced do not compare equal. The same rationale should apply to
25815<tt>list::merge</tt>. The intent of <tt>list::merge</tt> (AFAIK) is to
25816move nodes from one sorted <tt>list</tt> into another sorted
25817<tt>list</tt> without copying the elements. This is possible only if the
25818allocators compare equal.
25819</p>
25820
25821
25822<p><b>Proposed resolution:</b></p>
25823<p>
25824Relative to the August 2009 WP,
25825<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2857.pdf">N2857</a>,
25826change 23.3.4.4 [list.ops],
25827paragraphs 22-25 as follows:
25828</p>
25829
25830<blockquote>
25831<pre>void merge(list&amp;&amp; x);
25832template &lt;class Compare&gt; void merge(list&amp;&amp; x, Compare comp);
25833</pre>
25834<blockquote>
25835<p>
25836<i>Requires</i>: both the list and the argument list shall be sorted
25837according to operator&lt; or comp.
25838</p>
25839<p>
25840<i>Effects</i>: If <tt>(&amp;x == this)</tt> does nothing; otherwise, merges the
25841two sorted ranges <tt>[begin(), end())</tt> and <tt>[x.begin(),
25842x.end())</tt>. The result is a range in which the elements will be
25843sorted in non-decreasing order according to the ordering defined by
25844<tt>comp</tt>; that is, for every iterator <tt>i</tt>, in the range other than the
25845<tt>first</tt>, the condition <tt>comp(*i, *(i - 1)<ins>)</ins></tt> will be
25846<tt>false</tt>.
25847</p>
25848<p>
25849<i>Remarks</i>: Stable. If <tt>(&amp;x != this)</tt> the range <tt>[x.begin(), x.end())</tt> is
25850empty after the merge. <ins>No elements are copied by this operation.
25851The behavior is undefined if <tt>this-&gt;get_allocator() !=
25852x.get_allocator()</tt>.</ins>
25853</p>
25854<p>
25855<i>Complexity</i>: At most <tt>size() + x.size() - 1</tt> applications of <tt>comp</tt>
25856if <tt>(&amp;x != this)</tt>; otherwise, no applications of <tt>comp</tt> are performed. If an
25857exception is thrown other than by a comparison there are no effects.
25858</p>
25859</blockquote>
25860</blockquote>
25861
25862
25863
25864
25865
25866<hr>
25867<h3><a name="1216"></a>1216. LWG 1066 Incomplete?</h3>
25868<p><b>Section:</b> 18.8.6 [except.nested] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
25869 <b>Submitter:</b> Pete Becker <b>Opened:</b> 2009-09-25  <b>Last modified:</b> 2009-10-20</p>
25870<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#except.nested">active issues</a> in [except.nested].</p>
25871<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#except.nested">issues</a> in [except.nested].</p>
25872<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
25873<p><b>Discussion:</b></p>
25874<p>
25875LWG <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1066">1066</a> adds <tt>[[noreturn]]</tt> to a bunch of things.
25876It doesn't add it to <tt>rethrow_nested()</tt>, which seems like an obvious
25877candidate. I've made the changes indicated in the issue, and haven't
25878changed <tt>rethrow_nested()</tt>.
25879</p>
25880
25881<p><i>[
258822009 Santa Cruz:
25883]</i></p>
25884
25885
25886<blockquote>
25887Move to Ready.
25888</blockquote>
25889
25890
25891
25892<p><b>Proposed resolution:</b></p>
25893<p>
25894Add <tt>[[noreturn]]</tt> to <tt>rethrow_nested()</tt> in 18.8.6 [except.nested].
25895</p>
25896
25897
25898
25899
25900
25901<hr>
25902<h3><a name="1218"></a>1218. mutex destructor synchronization</h3>
25903<p><b>Section:</b> 30.4.1 [thread.mutex.requirements] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
25904 <b>Submitter:</b> Jeffrey Yasskin <b>Opened:</b> 2009-09-30  <b>Last modified:</b> 2009-09-30</p>
25905<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#thread.mutex.requirements">active issues</a> in [thread.mutex.requirements].</p>
25906<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#thread.mutex.requirements">issues</a> in [thread.mutex.requirements].</p>
25907<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
25908<p><b>Discussion:</b></p>
25909<p>
25910If an object <tt>*o</tt> contains a mutex <tt>mu</tt> and a
25911correctly-maintained reference count <tt>c</tt>, is the following code
25912safe?
25913</p>
25914
25915<blockquote><pre>o-&gt;mu.lock();
25916bool del = (--(o-&gt;c) == 0);
25917o-&gt;mu.unlock();
25918if (del) { delete o; }
25919</pre></blockquote>
25920
25921<p>
25922If the implementation of <tt>mutex::unlock()</tt> can touch the mutex's
25923memory after the moment it becomes free, this wouldn't be safe, and
25924"Construction and destruction of an object of a Mutex type need not be
25925thread-safe" 30.4.1 [thread.mutex.requirements] may imply that
25926it's not safe. Still, it's useful to allow mutexes to guard reference
25927counts, and if it's not allowed, users are likely to write bugs.
25928</p>
25929
25930
25931<p><b>Proposed resolution:</b></p>
25932<p>
25933</p>
25934
25935
25936
25937
25938
25939<hr>
25940<h3><a name="1219"></a>1219. unique_lock::lock and resource_deadlock_would_occur</h3>
25941<p><b>Section:</b> 30.4.3.2.2 [thread.lock.unique.locking] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
25942 <b>Submitter:</b> Jeffrey Yasskin <b>Opened:</b> 2009-09-30  <b>Last modified:</b> 2009-09-30</p>
25943<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#thread.lock.unique.locking">active issues</a> in [thread.lock.unique.locking].</p>
25944<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#thread.lock.unique.locking">issues</a> in [thread.lock.unique.locking].</p>
25945<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
25946<p><b>Discussion:</b></p>
25947<p>
25948<tt>unique_lock::lock</tt> and friends raise
25949"<tt>resource_deadlock_would_occur</tt> -- if the current thread already
25950owns the mutex (i.e., on entry, <tt>owns</tt> is <tt>true</tt>)."  1)
25951The current thread owning a mutex is not the same as any particular
25952<tt>unique_lock::owns</tt> being <tt>true</tt>. 2) There's no need to
25953raise this exception for a <tt>recursive_mutex</tt> if <tt>owns</tt> is
25954<tt>false</tt>. 3) If <tt>owns</tt> is true, we need to raise some
25955exception or the unique_lock will lose track of whether to unlock itself
25956on destruction, but "deadlock" isn't it. For (3), s/bool owns/int
25957ownership_level/ would fix it.
25958</p>
25959
25960
25961<p><b>Proposed resolution:</b></p>
25962
25963
25964
25965
25966
25967<hr>
25968<h3><a name="1220"></a>1220. What does condition_variable wait on?</h3>
25969<p><b>Section:</b> 30.5 [thread.condition] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Tentatively Ready</a>
25970 <b>Submitter:</b> Jeffrey Yasskin <b>Opened:</b> 2009-09-30  <b>Last modified:</b> 2009-11-06</p>
25971<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#thread.condition">active issues</a> in [thread.condition].</p>
25972<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#thread.condition">issues</a> in [thread.condition].</p>
25973<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Tentatively%20Ready">Tentatively Ready</a> status.</p>
25974<p><b>Discussion:</b></p>
25975<p>
25976"Class <tt>condition_variable</tt> provides a condition variable that can only
25977wait on an object of type <tt>unique_lock</tt>" should say "...object of type
25978<tt>unique_lock&lt;mutex&gt;</tt>"
25979</p>
25980
25981<p><i>[
259822009-11-06 Howard adds:
25983]</i></p>
25984
25985
25986<blockquote>
25987Moved to Tentatively Ready after 5 positive votes on c++std-lib.
25988</blockquote>
25989
25990
25991
25992<p><b>Proposed resolution:</b></p>
25993<p>
25994Change 30.5 [thread.condition], p1:
25995</p>
25996
25997<blockquote>
25998Condition variables provide synchronization primitives used to block a
25999thread until notified by some other thread that some condition is met or
26000until a system time is reached. Class <tt>condition_variable</tt>
26001provides a condition variable that can only wait on an object of type
26002<tt>unique_lock<ins>&lt;mutex&gt;</ins></tt>, allowing maximum
26003efficiency on some platforms. Class <tt>condition_variable_any</tt>
26004provides a general condition variable that can wait on objects of
26005user-supplied lock types.
26006</blockquote>
26007
26008
26009
26010
26011
26012<hr>
26013<h3><a name="1221"></a>1221. condition_variable wording</h3>
26014<p><b>Section:</b> 30.5.1 [thread.condition.condvar] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
26015 <b>Submitter:</b> Jeffrey Yasskin <b>Opened:</b> 2009-09-30  <b>Last modified:</b> 2009-09-30</p>
26016<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#thread.condition.condvar">active issues</a> in [thread.condition.condvar].</p>
26017<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#thread.condition.condvar">issues</a> in [thread.condition.condvar].</p>
26018<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
26019<p><b>Discussion:</b></p>
26020<p>
2602130.5.1 [thread.condition.condvar] says:
26022</p>
26023
26024<blockquote>
26025<pre>~condition_variable();
26026</pre>
26027<blockquote>
26028<i>Precondition:</i> There shall be no thread blocked on <tt>*this</tt>.
26029[<i>Note:</i> That is, all threads shall have been notified; they may
26030subsequently block on the lock specified in the wait. Beware that
26031destroying a <tt>condition_variable</tt> object while the corresponding
26032predicate is <tt>false</tt> is likely to lead to undefined behavior.
26033&#8212; <i>end note</i>]
26034</blockquote>
26035</blockquote>
26036
26037<p>
26038The text hasn't introduced the notion of a "corresponding predicate"
26039yet.
26040</p>
26041
26042
26043<p><b>Proposed resolution:</b></p>
26044
26045
26046
26047
26048
26049<hr>
26050<h3><a name="1222"></a>1222. condition_variable incorrect effects for exception safety</h3>
26051<p><b>Section:</b> 30.5 [thread.condition] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
26052 <b>Submitter:</b> Jeffrey Yasskin <b>Opened:</b> 2009-09-30  <b>Last modified:</b> 2009-09-30</p>
26053<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#thread.condition">active issues</a> in [thread.condition].</p>
26054<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#thread.condition">issues</a> in [thread.condition].</p>
26055<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
26056<p><b>Discussion:</b></p>
26057<p>
2605830.5.1 [thread.condition.condvar] says:
26059</p>
26060
26061<blockquote>
26062<pre>void wait(unique_lock&lt;mutex&gt;&amp; lock);
26063</pre>
26064<blockquote>
26065<p>...</p>
26066<p>
26067<i>Effects:</i>
26068</p>
26069<ul>
26070<li>...</li>
26071<li>
26072If the function exits via an exception, <tt>lock.unlock()</tt> shall be
26073called prior to exiting the function scope.
26074</li>
26075</ul>
26076</blockquote>
26077</blockquote>
26078
26079<p>
26080Should that be <tt>lock.lock()</tt>?
26081</p>
26082
26083
26084<p><b>Proposed resolution:</b></p>
26085
26086<p>
26087Change 30.5.1 [thread.condition.condvar] p10:
26088</p>
26089
26090<blockquote>
26091<pre>void wait(unique_lock&lt;mutex&gt;&amp; lock);
26092</pre>
26093<blockquote>
26094<p>...</p>
26095<p>
26096<i>Effects:</i>
26097</p>
26098<ul>
26099<li>...</li>
26100<li>
26101If the function exits via an exception, <tt>lock.<del>un</del>lock()</tt> shall be
26102called prior to exiting the function scope.
26103</li>
26104</ul>
26105</blockquote>
26106</blockquote>
26107
26108<p>
26109And make a similar change in p16, and in 30.5.2 [thread.condition.condvarany],
26110p8 and p13.
26111</p>
26112
26113
26114
26115
26116
26117
26118<hr>
26119<h3><a name="1223"></a>1223. condition_variable_any lock matching?</h3>
26120<p><b>Section:</b> 30.5.2 [thread.condition.condvarany] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
26121 <b>Submitter:</b> Jeffrey Yasskin <b>Opened:</b> 2009-09-30  <b>Last modified:</b> 2009-09-30</p>
26122<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#thread.condition.condvarany">active issues</a> in [thread.condition.condvarany].</p>
26123<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#thread.condition.condvarany">issues</a> in [thread.condition.condvarany].</p>
26124<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
26125<p><b>Discussion:</b></p>
26126<p>
26127For <tt>condition_variable_any</tt>, must all lock arguments to concurrent wait calls
26128"match" in some way, similar to the requirement in
2612930.5.1 [thread.condition.condvar] that <tt>lock.mutex()</tt> returns the same
26130value for each of the lock arguments supplied by all concurrently
26131waiting threads (via <tt>wait</tt> or <tt>timed_wait</tt>)?
26132</p>
26133
26134
26135
26136<p><b>Proposed resolution:</b></p>
26137
26138
26139
26140
26141
26142<hr>
26143<h3><a name="1224"></a>1224. condition_variable_any support for recursive mutexes?</h3>
26144<p><b>Section:</b> 30.5.2 [thread.condition.condvarany] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
26145 <b>Submitter:</b> Jeffrey Yasskin <b>Opened:</b> 2009-09-30  <b>Last modified:</b> 2009-09-30</p>
26146<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#thread.condition.condvarany">active issues</a> in [thread.condition.condvarany].</p>
26147<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#thread.condition.condvarany">issues</a> in [thread.condition.condvarany].</p>
26148<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
26149<p><b>Discussion:</b></p>
26150<p>
26151For <tt>condition_variable_any</tt>, are recursive mutexes allowed? (I think "no")
26152</p>
26153
26154
26155
26156<p><b>Proposed resolution:</b></p>
26157
26158
26159
26160
26161
26162<hr>
26163<h3><a name="1225"></a>1225. C++0x result_of issue </h3>
26164<p><b>Section:</b> 20.7.4 [func.ret] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
26165 <b>Submitter:</b> Sebastian Gesemann <b>Opened:</b> 2009-10-05  <b>Last modified:</b> 2009-10-17</p>
26166<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#func.ret">issues</a> in [func.ret].</p>
26167<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
26168<p><b>Discussion:</b></p>
26169<p>
26170I think the text about <tt>std::result_of</tt> could be a little more precise.
26171Quoting from
26172<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2960.pdf">N2960</a>...
26173</p>
26174
26175<blockquote>
26176<p>
2617720.7.4 [func.ret] Function object return types
26178</p>
26179
26180<pre>template&lt;class&gt; class result_of;
26181
26182template&lt;class Fn, class... ArgTypes&gt;
26183class result_of&lt;Fn(ArgTypes...)&gt; {
26184public:
26185  typedef <i>see below</i> type;
26186};
26187</pre>
26188
26189<p>
26190Given an rvalue <tt>fn</tt> of type <tt>Fn</tt> and values <tt>t1, t2,
26191..., tN</tt> of types <tt>T1, T2, ... TN</tt> in <tt>ArgTypes</tt>
26192respectivly, the <tt>type</tt> member is the result type of the
26193expression <tt>fn(t1,t2,...,tN)</tt>. the values <tt>ti</tt> are lvalues
26194when the corresponding type <tt>Ti</tt> is an lvalue-reference type, and
26195rvalues otherwise.
26196</p>
26197</blockquote>
26198
26199<p>
26200This text doesn't seem to consider lvalue reference types for <tt>Fn</tt>.
26201Also, it's not clear whether this class template can be used for
26202"SFINAE" like <tt>std::enable_if</tt>. Example:
26203</p>
26204
26205<blockquote><pre>template&lt;typename Fn, typename... Args&gt;
26206typename std::result_of&lt;Fn(Args...)&gt;::type
26207apply(Fn &amp;&amp; fn, Args &amp;&amp; ...args)
26208{
26209  // Fn may be an lvalue reference, too
26210  return std::forward&lt;Fn&gt;(fn)(std::forward&lt;Args&gt;(args)...);
26211}
26212</pre></blockquote>
26213
26214<p>
26215Either <tt>std::result_of&lt;...&gt;</tt> can be instantiated and simply may not have
26216a typedef "<tt>type</tt>" (--&gt;SFINAE) or instantiating the class template for
26217some type combinations will be a "hard" compile-time error.
26218</p>
26219
26220
26221<p><b>Proposed resolution:</b></p>
26222
26223<p><i>[
26224These changes will require compiler support
26225]</i></p>
26226
26227
26228<p>
26229Change 20.7.4 [func.ret]:
26230</p>
26231
26232<blockquote><pre>template&lt;class&gt; class result_of; // <i>undefined</i>
26233
26234template&lt;class Fn, class... ArgTypes&gt;
26235class result_of&lt;Fn(ArgTypes...)&gt; {
26236public:
26237  <del>typedef</del> <i>see below</i> <del>type;</del>
26238};
26239</pre>
26240
26241<p><del>
26242Given an rvalue <tt>fn</tt> of type <tt>Fn</tt> and values <tt>t1, t2,
26243..., tN</tt> of types <tt>T1, T2, ... TN</tt> in <tt>ArgTypes</tt>
26244respectivly, the <tt>type</tt> member is the result type of the
26245expression <tt>fn(t1,t2,...,tN)</tt>. the values <tt>ti</tt> are lvalues
26246when the corresponding type <tt>Ti</tt> is an lvalue-reference type, and
26247rvalues otherwise.
26248</del></p>
26249
26250<p>
26251<ins>The class template <tt>result_of</tt> shall meet the requirements of a
26252<i>TransformationTrait</i>: Given the types <tt>Fn</tt>, <tt>T1</tt>, <tt>T2</tt>, ..., <tt>TN</tt> every
26253template specialization <tt>result_of&lt;Fn(T1,T2,...,TN)&gt;</tt> shall define the
26254member typedef type equivalent to <tt>decltype(<i>RE</i>)</tt> if and only if
26255the expression <tt><i>RE</i></tt>
26256</ins></p>
26257
26258<blockquote><pre><ins>
26259value&lt;Fn&gt;() ( value&lt;T1&gt;(), value&lt;T2&gt;(), ... value&lt;TN&gt;()  )
26260</ins></pre></blockquote>
26261
26262<p><ins>
26263would be well-formed. Otherwise, there shall be no member typedef
26264<tt>type</tt> defined.
26265</ins></p>
26266
26267</blockquote>
26268 
26269<p><i>[
26270The <tt>value&lt;&gt;</tt> helper function is a utility Daniel Kr�gler
26271proposed in
26272<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2958.html">N2958</a>.
26273]</i></p>
26274
26275
26276
26277
26278
26279
26280<hr>
26281<h3><a name="1226"></a>1226. Incomplete changes of #890</h3>
26282<p><b>Section:</b> 30.6.2 [futures.errors] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Tentatively Ready</a>
26283 <b>Submitter:</b> Daniel Kr�gler <b>Opened:</b> 2009-10-05  <b>Last modified:</b> 2009-10-27</p>
26284<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Tentatively%20Ready">Tentatively Ready</a> status.</p>
26285<p><b>Discussion:</b></p>
26286<p>
26287Defect issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#890">890</a> overlooked to adapt the <tt>future_category</tt> from
2628830.6.1 [futures.overview] and 30.6.2 [futures.errors]:
26289</p>
26290
26291<blockquote><pre>extern const error_category* const future_category;
26292</pre></blockquote>
26293
26294<p>
26295which should be similarly transformed into function form.
26296</p>
26297
26298<p><i>[
262992009-10-27 Howard:
26300]</i></p>
26301
26302
26303<blockquote>
26304Moved to Tentatively Ready after 5 positive votes on c++std-lib.
26305</blockquote>
26306
26307
26308
26309<p><b>Proposed resolution:</b></p>
26310<ol>
26311<li>
26312<p>
26313Change in 30.6.1 [futures.overview], header <tt>&lt;future&gt;</tt> synopsis:
26314</p>
26315
26316<blockquote><pre><del>extern</del> const error_category<ins>&amp;</ins><del>* const</del> future_category<ins>()</ins>;
26317</pre></blockquote>
26318</li>
26319
26320<li>
26321<p>
26322Change in 30.6.2 [futures.errors]:
26323</p>
26324
26325<blockquote><pre><del>extern</del> const error_category<ins>&amp;</ins><del>* const</del> future_category<ins>()</ins>;
26326</pre>
26327
26328<blockquote>
26329<p>
26330<del>1- <tt>future_category</tt> shall point to a statically initialized object
26331of a type derived from class <tt>error_category</tt>.</del>
26332</p>
26333<p>
26334<ins>1- <i>Returns:</i> A reference to an object of a type
26335derived from class <tt>error_category</tt>.</ins>
26336</p>
26337</blockquote>
26338
26339<pre>constexpr error_code make_error_code(future_errc e);
26340</pre>
26341
26342<blockquote>
263433 <i>Returns:</i> <tt>error_code(static_cast&lt;int&gt;(e),
26344<del>*</del>future_category<ins>()</ins>)</tt>.
26345</blockquote>
26346
26347<pre>constexpr error_code make_error_condition(future_errc e);
26348</pre>
26349
26350<blockquote>
263514 <i>Returns:</i> <tt>error_condition(static_cast&lt;int&gt;(e),
26352<del>*</del>future_category<ins>()</ins>)</tt>.
26353</blockquote>
26354</blockquote>
26355</li>
26356</ol>
26357
26358
26359
26360
26361
26362<hr>
26363<h3><a name="1227"></a>1227. <tt>&lt;bitset&gt;</tt> synopsis overspecified</h3>
26364<p><b>Section:</b> 20.3.7 [template.bitset] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
26365 <b>Submitter:</b> Bo Persson <b>Opened:</b> 2009-10-05  <b>Last modified:</b> 2009-10-26</p>
26366<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#template.bitset">active issues</a> in [template.bitset].</p>
26367<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#template.bitset">issues</a> in [template.bitset].</p>
26368<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
26369<p><b>Discussion:</b></p>
26370<p>
26371The resolutions to some library defect reports, like <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#1178">1178</a>
26372requires that <tt>#includes</tt> in each synopsis should be taken
26373literally. This means that the <tt>&lt;bitset&gt;</tt> header now
26374<em>must</em> include <tt>&lt;stdexcept&gt;</tt>, even though none of the
26375exceptions are mentioned in the <tt>&lt;bitset&gt;</tt> header.
26376</p>
26377<p>
26378Many other classes are required to throw exceptions like
26379<tt>invalid_argument</tt> and <tt>out_of_range</tt>, without explicitly
26380including <tt>&lt;stdexcept&gt;</tt> in their synopsis. It is totally
26381possible for implementations to throw the needed exceptions from utility
26382functions, whose implementations are not visible in the headers.
26383</p>
26384<p>
26385I propose that <tt>&lt;stdexcept&gt;</tt> is removed from the
26386<tt>&lt;bitset&gt;</tt> header.
26387</p>
26388
26389<p><i>[
263902009-10 Santa Cruz:
26391]</i></p>
26392
26393
26394<blockquote>
26395Moved to Ready.
26396</blockquote>
26397
26398
26399
26400<p><b>Proposed resolution:</b></p>
26401<p>
26402Change 20.3.7 [template.bitset]:
26403</p>
26404
26405<blockquote><pre>#include &lt;cstddef&gt;        // for size_t
26406#include &lt;string&gt;
26407<del>#include &lt;stdexcept&gt;      // for invalid_argument,</del>
26408                          <del>// out_of_range, overflow_error</del>
26409#include &lt;iosfwd&gt;         // for istream, ostream
26410namespace std {
26411...
26412</pre></blockquote>
26413
26414
26415
26416
26417
26418<hr>
26419<h3><a name="1228"></a>1228. User-specialized nothrow type traits</h3>
26420<p><b>Section:</b> 20.6.4.3 [meta.unary.prop] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Open">Open</a>
26421 <b>Submitter:</b> Alisdair Meredith <b>Opened:</b> 2009-10-07  <b>Last modified:</b> 2009-10-26</p>
26422<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#meta.unary.prop">active issues</a> in [meta.unary.prop].</p>
26423<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#meta.unary.prop">issues</a> in [meta.unary.prop].</p>
26424<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Open">Open</a> status.</p>
26425<p><b>Discussion:</b></p>
26426<p>
26427According to p1 20.6.2 [meta.type.synop]:
26428</p>
26429
26430<blockquote>
26431The behavior of a program that adds specializations for any of the class
26432templates defined in this subclause is undefined unless otherwise
26433specified.
26434</blockquote>
26435
26436<p>
26437I believe we should 'otherwise specify' for the nothrow traits, are
26438these are exactly the use cases where the end user actually has more
26439information than the compiler.
26440</p>
26441
26442<p><i>[
264432009-10 Santa Cruz:
26444]</i></p>
26445
26446
26447<blockquote>
26448Moved to Open.  Definitely need to give the users the ability to ensure
26449that the traits give the right answers. Unsure we want to give them the
26450ability to say this in more than one way. Believes the noexcept proposal
26451already gives this.
26452</blockquote>
26453
26454
26455
26456<p><b>Proposed resolution:</b></p>
26457<p>
26458Add the following comment:
26459</p>
26460
26461<blockquote>
26462user specialization permitted to derive from <tt>std::true_type</tt> when the
26463operation is known not to throw.
26464</blockquote>
26465
26466<p>
26467to the following traits in 20.6.4.3 [meta.unary.prop] Table 43 Type
26468property predicates.
26469</p>
26470
26471<p><i>[
26472This may require a new Comments column
26473]</i></p>
26474
26475
26476<blockquote><pre>has_nothrow_default_constructor
26477has_nothrow_copy_constructor
26478has_nothrow_assign
26479</pre></blockquote>
26480
26481
26482
26483
26484
26485<hr>
26486<h3><a name="1231"></a>1231. <tt>weak_ptr</tt> comparisons incompletely resolved</h3>
26487<p><b>Section:</b> 20.8.15.3.5 [util.smartptr.weak.obs] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Tentatively Ready</a>
26488 <b>Submitter:</b> Daniel Kr�gler <b>Opened:</b> 2009-10-10  <b>Last modified:</b> 2009-11-06</p>
26489<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Tentatively%20Ready">Tentatively Ready</a> status.</p>
26490<p><b>Discussion:</b></p>
26491<p>
26492The
26493<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2637.pdf">n2637</a>
26494paper suggested several updates of the ordering semantics of
26495<tt>shared_ptr</tt>
26496and <tt>weak_ptr</tt>, among those the explicit comparison operators of <tt>weak_ptr</tt> were
26497removed/deleted, instead a corresponding functor <tt>owner_less</tt> was added.
26498The problem
26499is that
26500<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2637.pdf">n2637</a>
26501did not clearly enough specify, how the previous wording
26502parts describing
26503the comparison semantics of <tt>weak_ptr</tt> should be removed.
26504</p>
26505
26506<p><i>[
265072009-11-06 Howard adds:
26508]</i></p>
26509
26510
26511<blockquote>
26512Moved to Tentatively Ready after 5 positive votes on c++std-lib.
26513</blockquote>
26514
26515
26516
26517<p><b>Proposed resolution:</b></p>
26518<ol>
26519<li>
26520<p>
26521Change 20.8.15.3 [util.smartptr.weak]/2 as described, the intention is to fix
26522the now no longer valid
26523requirement that <tt>weak_ptr</tt> is <tt>LessComparable</tt> [Note the deleted comma]:
26524</p>
26525
26526<blockquote>
26527Specializations of <tt>weak_ptr</tt> shall be <tt>CopyConstructible</tt><del>,</del>
26528<ins>and</ins> <tt>CopyAssignable</tt>,
26529<del>and <tt>LessThanComparable</tt>,</del> allowing their use in standard containers.
26530</blockquote>
26531</li>
26532
26533<li>
26534<p>
26535In 20.8.15.3.5 [util.smartptr.weak.obs] remove the paragraphs 9-11 including prototype:
26536</p>
26537
26538<blockquote>
26539<del>template&lt;class T, class U&gt; bool operator&lt;(const weak_ptr&lt;T&gt;&amp; a, const weak_ptr&lt;U&gt;&amp; b);</del>
26540
26541<p>
26542<del><i>Returns:</i> an unspecified value such that</del>
26543</p>
26544<ul>
26545<li>
26546<del><tt>operator&lt;</tt> is a strict weak ordering as described in 25.4;</del>
26547</li>
26548<li>
26549<del>under the equivalence relation defined by <tt>operator&lt;</tt>, <tt>!(a
26550&lt; b) &amp;&amp; !(b &lt; a)</tt>, two <tt>weak_ptr</tt> instances are
26551equivalent if and only if they share ownership or are both empty.</del>
26552</li>
26553</ul>
26554
26555<p>
26556<del><i>Throws:</i> nothing.</del>
26557</p>
26558
26559<p>
26560<del>[<i>Note:</i> Allows <tt>weak_ptr</tt> objects to be used as keys in associative
26561containers. &#8212; <i>end note</i>]</del>
26562</p>
26563</blockquote>
26564</li>
26565</ol>
26566
26567
26568
26569
26570
26571<hr>
26572<h3><a name="1233"></a>1233. Missing <tt>unique_ptr</tt> signatures in synopsis</h3>
26573<p><b>Section:</b> 20.8 [memory] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#NAD%20Editorial">Tentatively NAD Editorial</a>
26574 <b>Submitter:</b> Daniel Kr�gler <b>Opened:</b> 2009-10-11  <b>Last modified:</b> 2009-11-04</p>
26575<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#memory">issues</a> in [memory].</p>
26576<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Tentatively%20NAD%20Editorial">Tentatively NAD Editorial</a> status.</p>
26577<p><b>Discussion:</b></p>
26578<p>
26579Related to <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#296">296</a>.  Some <tt>unique_ptr</tt> signatures are missing
26580from the synopsis in 20.8 [memory].
26581</p>
26582
26583<p><i>[
265842009-11-04 Howard adds:
26585]</i></p>
26586
26587
26588<blockquote>
26589Moved to Tentatively NAD Editorial.  The editor has adopted the fix.
26590</blockquote>
26591
26592
26593<p><b>Proposed resolution:</b></p>
26594<p>
26595Add in 20.8 [memory], Header <tt>&lt;memory&gt;</tt> synopsis
26596missing declarations as shown below:
26597</p>
26598
26599<blockquote><pre>// 20.8.11 Class unique_ptr:
26600template &lt;class X&gt; class default_delete;
26601<ins>template&lt;class T&gt; struct default_delete&lt;T[]&gt;;</ins>
26602template &lt;class X, class D = default_delete&lt;T&gt;&gt; class unique_ptr;
26603<ins>template&lt;class T, class D&gt; class unique_ptr&lt;T[], D&gt;;</ins>
26604
26605<ins>template&lt;class T, class D&gt; void swap(unique_ptr&lt;T, D&gt;&amp; x, unique_ptr&lt;T, D&gt;&amp; y);</ins>
26606
26607<ins>template&lt;class T1, class D1, class T2, class D2&gt;
26608bool operator==(const unique_ptr&lt;T1, D1&gt;&amp; x, const unique_ptr&lt;T2, D2&gt;&amp; y);</ins>
26609<ins>template&lt;class T1, class D1, class T2, class D2&gt;
26610bool operator!=(const unique_ptr&lt;T1, D1&gt;&amp; x, const unique_ptr&lt;T2, D2&gt;&amp; y);</ins>
26611<ins>template&lt;class T1, class D1, class T2, class D2&gt;
26612bool operator&lt;(const unique_ptr&lt;T1, D1&gt;&amp; x, const unique_ptr&lt;T2, D2&gt;&amp; y);</ins>
26613<ins>template&lt;class T1, class D1, class T2, class D2&gt;
26614bool operator&lt;=(const unique_ptr&lt;T1, D1&gt;&amp; x, const unique_ptr&lt;T2, D2&gt;&amp; y);</ins>
26615<ins>template&lt;class T1, class D1, class T2, class D2&gt;
26616bool operator&gt;(const unique_ptr&lt;T1, D1&gt;&amp; x, const unique_ptr&lt;T2, D2&gt;&amp; y);</ins>
26617<ins>template&lt;class T1, class D1, class T2, class D2&gt;
26618bool operator&gt;=(const unique_ptr&lt;T1, D1&gt;&amp; x, const unique_ptr&lt;T2, D2&gt;&amp; y);</ins>
26619</pre></blockquote>
26620
26621
26622
26623
26624
26625<hr>
26626<h3><a name="1234"></a>1234. "Do the right thing" and NULL</h3>
26627<p><b>Section:</b> 23.2.3 [sequence.reqmts] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
26628 <b>Submitter:</b> Matt Austern <b>Opened:</b> 2009-10-09  <b>Last modified:</b> 2009-10-13</p>
26629<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#sequence.reqmts">active issues</a> in [sequence.reqmts].</p>
26630<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#sequence.reqmts">issues</a> in [sequence.reqmts].</p>
26631<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
26632<p><b>Discussion:</b></p>
26633<p>
26634On g++ 4.2.4 (x86_64-linux-gnu), the following file gives a compile
26635error:
26636</p>
26637
26638<blockquote><pre>#include &lt;vector&gt;
26639void foo() { std::vector&lt;int*&gt; v(500l, NULL); }
26640</pre></blockquote>
26641
26642<p>
26643Is this supposed to work? 
26644</p>
26645
26646<p>
26647The issue: if <tt>NULL</tt> happens to be defined as <tt>0l</tt>, this is an invocation of
26648the constructor with two arguments of the same integral type.
2664923.2.3 [sequence.reqmts]/11 says that this will behave as if the the
26650overloaded constructor
26651</p>
26652
26653<blockquote><pre>X(size_type, const value_type&amp; = value_type(),
26654  const allocator_type&amp; = allocator_type())
26655</pre></blockquote>
26656
26657<p>
26658were called instead, with the arguments
26659<tt>static_cast&lt;size_type&gt;(first)</tt>, <tt>last</tt> and
26660<tt>alloc</tt>, respectively. However, it does not say whether this
26661actually means invoking that constructor with the exact textual form of
26662the arguments as supplied by the user, or whether the standard permits
26663an implementation to invoke that constructor with variables of the same
26664type and value as what the user passed in. In most cases this is a
26665distinction without a difference. In this particular case it does make a
26666difference, since one of those things is a null pointer constant and the
26667other is not.
26668</p>
26669
26670<p>
26671Note that an implementation based on forwarding functions will use the
26672latter interpretation.
26673</p>
26674
26675
26676<p><b>Proposed resolution:</b></p>
26677
26678
26679
26680
26681
26682<hr>
26683<h3><a name="1237"></a>1237. Constrained error_code/error_condition members</h3>
26684<p><b>Section:</b> 19.5 [syserr] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Ready</a>
26685 <b>Submitter:</b> Daniel Kr�gler <b>Opened:</b> 2009-10-14  <b>Last modified:</b> 2009-10-26</p>
26686<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#syserr">issues</a> in [syserr].</p>
26687<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Ready">Ready</a> status.</p>
26688<p><b>Discussion:</b></p>
26689<p>
26690I'm just reflecting on the now SFINAE-constrained constructors
26691and assignment operators of <tt>error_code</tt> and <tt>error_condition</tt>:
26692</p>
26693<p>
26694These are the <em>only</em> library components that are pro-actively
26695announcing that they are using <tt>std::enable_if</tt> as constraining tool,
26696which has IMO several disadvantages:
26697</p>
26698
26699<ol>
26700<li>
26701<p>
26702With the availability of template default arguments and
26703decltype, using <tt>enable_if</tt> in C++0x standard library, seems
26704unnecessary restricting implementation freedom. E.g. there
26705should be not need for a useless specification of a dummy
26706default function argument, which only confuses the reader.
26707A more reasonable implementation could e.g. be
26708</p>
26709
26710<blockquote><pre>template &lt;class ErrorCodeEnum
26711 class = typename enable_if&lt;is_error_code_enum&lt;ErrorCodeEnum&gt;::value&gt;::type&gt;
26712error_code(ErrorCodeEnum e);
26713</pre></blockquote>
26714
26715<p>
26716As currently specified, the function signatures are so unreadable,
26717that errors quite easily happen, see e.g. <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1229">1229</a>.
26718</p>
26719</li>
26720
26721<li>
26722<p>
26723We have a <em>lot</em> of constrained functions in other places, that
26724now have a standard phrase that is easily understandable:
26725</p>
26726
26727<blockquote>
26728<i>Remarks:</i> This constructor/function shall participate in overload
26729resolution if and only if X.
26730</blockquote>
26731
26732<p>
26733where X describes the condition. Why should these components deviate?
26734</p>
26735</li>
26736
26737<li>
26738<p>
26739If <tt>enable_if</tt> would <em>not</em> be explicitly specified, the standard library
26740is much better prepared for the future. It would also be possible, that
26741libraries with partial support for not-yet-standard-concepts could provide
26742a much better diagnostic as is possible with <tt>enable_if</tt>. This again
26743would allow for experimental concept implementations in the wild,
26744which as a result would make concept standardization a much more
26745natural thing, similar to the way as templates were standardized
26746in C++.
26747</p>
26748
26749<p>
26750In summary: I consider it as a library defect that <tt>error_code</tt> and
26751<tt>error_condition</tt> explicitly require a dependency to <tt>enable_if</tt> and
26752do limit implementation freedom and I volunteer to prepare a
26753corresponding resolution.
26754</p>
26755</li>
26756</ol>
26757
26758<p><i>[
267592009-10-18 Beman adds:
26760]</i></p>
26761
26762
26763<blockquote>
26764I support this proposed resolution, and thank Daniel for writing it up.
26765</blockquote>
26766
26767<p><i>[
267682009-10 Santa Cruz:
26769]</i></p>
26770
26771
26772<blockquote>
26773Moved to Ready.
26774</blockquote>
26775
26776
26777
26778<p><b>Proposed resolution:</b></p>
26779<p><i>[
26780Should this resolution be accepted, I recommend to resolve <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1229">1229</a> as NAD
26781]</i></p>
26782
26783
26784<ol>
26785<li>
26786<p>
26787In 19.5.2.1 [syserr.errcode.overview]/1, class <tt>error_code</tt>,
26788change as indicated:
26789</p>
26790
26791<blockquote><pre>// 19.5.2.2 constructors:
26792error_code();
26793error_code(int val, const error_category&amp; cat);
26794template &lt;class ErrorCodeEnum&gt;
26795  error_code(ErrorCodeEnum e<del>,
26796    typename enable_if&lt;is_error_code_enum&lt;ErrorCodeEnum&gt;::value&gt;::type * = 0</del>);
26797
26798// 19.5.2.3 modifiers:
26799void assign(int val, const error_category&amp; cat);
26800template &lt;class ErrorCodeEnum&gt;
26801  <del>typename enable_if&lt;is_error_code_enum&lt;ErrorCodeEnum&gt;::value&gt;::type</del><ins>error_code</ins>&amp;
26802    operator=(ErrorCodeEnum e);
26803void clear();
26804</pre></blockquote>
26805</li>
26806
26807<li>
26808<p>
26809Change 19.5.2.2 [syserr.errcode.constructors] around the prototype before p. 7:
26810</p>
26811
26812<blockquote><pre>template &lt;class ErrorCodeEnum&gt;
26813error_code(ErrorCodeEnum e<del>,
26814  typename enable_if&lt;is_error_code_enum&lt;ErrorCodeEnum&gt;::value&gt;::type * = 0</del>);
26815</pre>
26816<blockquote>
26817<p>
26818<ins><i>Remarks:</i> This constructor shall not participate in overload
26819resolution, unless
26820<tt>is_error_code_enum&lt;ErrorCodeEnum&gt;::value == true</tt>.</ins>
26821</p>
26822</blockquote>
26823</blockquote>
26824</li>
26825
26826<li>
26827<p>
26828Change 19.5.2.3 [syserr.errcode.modifiers] around the prototype before p. 3:
26829</p>
26830
26831<blockquote><pre>template &lt;class ErrorCodeEnum&gt;
26832  <del>typename enable_if&lt;is_error_code_enum&lt;ErrorCodeEnum&gt;::value&gt;::type</del><ins>error_code</ins>&amp;
26833    operator=(ErrorCodeEnum e);
26834</pre>
26835
26836<blockquote>
26837<ins><i>Remarks:</i> This operator shall not participate in overload resolution, unless
26838<tt>is_error_code_enum&lt;ErrorCodeEnum&gt;::value == true</tt>.</ins>
26839</blockquote>
26840</blockquote>
26841</li>
26842
26843<li>
26844<p>
26845In 19.5.3.1 [syserr.errcondition.overview]/1, class <tt>error_condition</tt>, change
26846as indicated:
26847</p>
26848
26849<blockquote><pre>// 19.5.3.2 constructors:
26850error_condition();
26851error_condition(int val, const error_category&amp; cat);
26852template &lt;class ErrorConditionEnum&gt;
26853  error_condition(ErrorConditionEnum e<del>,
26854    typename enable_if&lt;is_error_condition_enum&lt;ErrorConditionEnum&gt;::type* = 0</del>);
26855
26856// 19.5.3.3 modifiers:
26857void assign(int val, const error_category&amp; cat);
26858template&lt;<del>typename</del><ins>class</ins> ErrorConditionEnum&gt;
26859  <del>typename enable_if&lt;is_error_condition_enum&lt;ErrorConditionEnum&gt;, error_code&gt;::type</del><ins>error_condition</ins> &amp;
26860    operator=( ErrorConditionEnum e );
26861void clear();
26862</pre></blockquote>
26863</li>
26864
26865<li>
26866<p>
26867Change 19.5.3.2 [syserr.errcondition.constructors] around the
26868prototype before p. 7:
26869</p>
26870
26871<blockquote><pre>template &lt;class ErrorConditionEnum&gt;
26872  error_condition(ErrorConditionEnum e<del>,
26873    typename enable_if&lt;is_error_condition_enum&lt;ErrorConditionEnum&gt;::value&gt;::type* = 0</del>);
26874</pre>
26875<blockquote>
26876<ins><i>Remarks:</i> This constructor shall not participate in overload
26877resolution, unless
26878<tt>is_error_condition_enum&lt;ErrorConditionEnum&gt;::value == true</tt>.</ins>
26879</blockquote>
26880</blockquote>
26881</li>
26882
26883<li>
26884<p>
26885Change 19.5.3.3 [syserr.errcondition.modifiers] around the
26886prototype before p. 3:
26887</p>
26888
26889<blockquote><pre>template &lt;class ErrorConditionEnum&gt;
26890  <del>typename enable_if&lt;is_error_condition_enum&lt;ErrorConditionEnum&gt;::value&gt;::type</del><ins>error_condition</ins>&amp;
26891    operator=(ErrorConditionEnum e);
26892</pre>
26893
26894<blockquote>
26895<p>
26896<ins><i>Remarks:</i> This operator shall not participate in overload resolution, unless
26897<tt>is_error_condition_enum&lt;ErrorConditionEnum&gt;::value == true</tt>.</ins>
26898</p>
26899
26900<p>
26901<i>Postcondition:</i> <tt>*this == make_error_condition(e)</tt>.
26902</p>
26903
26904<p>
26905<ins><i>Returns:</i> <tt>*this</tt></ins>
26906</p>
26907</blockquote>
26908</blockquote>
26909
26910</li>
26911</ol>
26912
26913
26914
26915
26916
26917
26918<hr>
26919<h3><a name="1238"></a>1238. defining algorithms taking iterator for range</h3>
26920<p><b>Section:</b> 25 [algorithms] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#NAD%20Future">Tentatively NAD Future</a>
26921 <b>Submitter:</b> Alisdair Meredith <b>Opened:</b> 2009-10-15  <b>Last modified:</b> 2009-11-03</p>
26922<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#algorithms">active issues</a> in [algorithms].</p>
26923<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#algorithms">issues</a> in [algorithms].</p>
26924<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Tentatively%20NAD%20Future">Tentatively NAD Future</a> status.</p>
26925<p><b>Discussion:</b></p>
26926<p>
26927The library has many algorithms that take a source range represented by
26928a pair of iterators, and the start of some second sequence given by a
26929single iterator.  Internally, these algorithms will produce undefined
26930behaviour if the second 'range' is not as large as the input range, but
26931none of the algorithms spell this out in Requires clauses, and there is
26932no catch-all wording to cover this in clause 17 or the front matter of
2693325.
26934</p>
26935
26936<p>
26937There was an attempt to provide such wording in paper
26938<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2944.pdf">n2944</a>
26939but this
26940seems incidental to the focus of the paper, and getting the wording of
26941this issue right seems substantially more difficult than the simple
26942approach taken in that paper.  Such wording will be removed from an
26943updated paper, and hopefully tracked via the LWG issues list instead.
26944</p>
26945
26946<p>
26947It seems there are several classes of problems here and finding wording
26948to solve all in one paragraph could be too much.  I suspect we need
26949several overlapping requirements that should cover the desired range of
26950behaviours.
26951</p>
26952
26953<p>
26954Motivating examples:
26955</p>
26956
26957<p>
26958A good initial example is the <tt>swap_ranges</tt> algorithm.  Here there is a
26959clear requirement that <tt>first2</tt> refers to the start of a valid range at
26960least as long as the range <tt>[first1, last1)</tt>.  <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2944.pdf">n2944</a> tries to solve this
26961by positing a hypothetical <tt>last2</tt> iterator that is implied by the
26962signature, and requires <tt>distance(first2,last2) &lt; distance(first1,last1)</tt>.
26963 This mostly works, although I am uncomfortable assuming that <tt>last2</tt> is
26964clearly defined and well known without any description of how to obtain
26965it (and I have no idea how to write that).
26966</p>
26967
26968<p>
26969A second motivating example might be the <tt>copy</tt> algorithm.  Specifically,
26970let us image a call like:
26971</p>
26972
26973<blockquote><pre>copy(istream_iterator&lt;int&gt;(is),istream_iterator(),ostream_iterator&lt;int&gt;(os));
26974</pre></blockquote>
26975
26976<p>
26977In this case, our input iterators are literally simple <tt>InputIterators</tt>,
26978and the destination is a simple <tt>OutputIterator</tt>.  In neither case am I
26979happy referring to <tt>std::distance</tt>, in fact it is not possible for the
26980<tt>ostream_iterator</tt> at all as it does not meet the requirements.  However,
26981any wording we provide must cover both cases.  Perhaps we might deduce
26982<tt>last2 == ostream_iterator&lt;int&gt;{}</tt>, but that might not always be valid for
26983user-defined iterator types.  I can well imagine an 'infinite range'
26984that writes to <tt>/dev/null</tt> and has no meaningful <tt>last2</tt>.
26985</p>
26986
26987<p>
26988The motivating example in <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2944.pdf">n2944</a> is <tt>std::equal</tt>, and that seems to fall somewhere between the
26989two.
26990</p>
26991
26992<p>
26993Outlying examples might be <tt>partition_copy</tt> that takes two output
26994iterators, and the <tt>_n</tt> algorithms where a range is specified by a
26995specific number of iterations, rather than traditional iterator pair. 
26996We should also <em>not</em> accidentally apply inappropriate constraints to
26997<tt>std::rotate</tt> which takes a third iterator that is not intended to be a
26998separate range at all.
26999</p>
27000
27001<p>
27002I suspect we want some wording similar to:
27003</p>
27004
27005<blockquote>
27006For algorithms that operate on ranges where the end iterator of the
27007second range is not specified, the second range shall contain at least
27008as many elements as the first.
27009</blockquote>
27010
27011<p>
27012I don't think this quite captures the intent yet though.  I am not sure
27013if 'range' is the right term here rather than sequence.  More awkwardly,
27014I am not convinced we can describe an Output sequence such as produce by
27015an <tt>ostream_iterator</tt> as "containing elements", at least not as a
27016precondition to the call before they have been written.
27017</p>
27018
27019<p>
27020Another idea was to describe require that the trailing iterator support
27021at least distance(input range) applications of <tt>operator++</tt> and may be
27022written through the same number of times if a mutable/output iterator.
27023</p>
27024
27025<p>
27026We might also consider handling the case of an output range vs. an input
27027range in separate paragraphs, if that simplifies how we describe some of
27028these constraints.
27029</p>
27030
27031<p><i>[
270322009-11-03 Howard adds:
27033]</i></p>
27034
27035
27036<blockquote>
27037Moved to Tentatively NAD Future after 5 positive votes on c++std-lib.
27038</blockquote>
27039
27040
27041<p><b>Proposed resolution:</b></p>
27042
27043
27044
27045
27046
27047<hr>
27048<h3><a name="1239"></a>1239. Defect report</h3>
27049<p><b>Section:</b> 20.6.4.3 [meta.unary.prop] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#NAD%20Editorial">Tentatively NAD Editorial</a>
27050 <b>Submitter:</b> David Abrahams <b>Opened:</b> 2009-10-16  <b>Last modified:</b> 2009-10-26</p>
27051<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#meta.unary.prop">active issues</a> in [meta.unary.prop].</p>
27052<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#meta.unary.prop">issues</a> in [meta.unary.prop].</p>
27053<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Tentatively%20NAD%20Editorial">Tentatively NAD Editorial</a> status.</p>
27054<p><b>Discussion:</b></p>
27055<p>
27056Table 43 defines a number of traits that yield true for arrays of class
27057types with the trait's property, but not arrays of other types with that
27058property.  For example, <tt>has_trivial_default_constructor</tt>:
27059</p>
27060
27061<blockquote>
27062<tt>T</tt> is a trivial type (3.9) or a class type with a trivial default
27063constructor (12.1) or an array of such a class type.
27064</blockquote>
27065
27066<p><i>[
270672009-10 post-Santa Cruz:
27068]</i></p>
27069
27070
27071<blockquote>
27072<p>
27073An array of a trivial type is a trivial type.
27074</p>
27075<p>
27076Mark as Tentatively NAD Editorial. The wording is OK as is,
27077since an array of a trivial type is a trivial type, but the wording as
27078proposed might be clearer.
27079</p>
27080</blockquote>
27081
27082
27083
27084<p><b>Proposed resolution:</b></p>
27085<p>
27086Change all the traits in question following this pattern:
27087</p>
27088
27089<blockquote>
27090<tt>T</tt> is a trivial type (3.9) or a class type with a trivial default
27091 constructor (12.1)<ins>,</ins> or an array of such a <del>class</del> type.
27092</blockquote>
27093
27094<p>
27095i.e., add a comma and delete a "class."
27096</p>
27097
27098
27099
27100
27101
27102<hr>
27103<h3><a name="1240"></a>1240. Deleted comparison functions of std::function not  needed</h3>
27104<p><b>Section:</b> 20.7.15.2 [func.wrap.func] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
27105 <b>Submitter:</b> Daniel Kr�gler <b>Opened:</b> 2009-10-18  <b>Last modified:</b> 2009-10-19</p>
27106<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#func.wrap.func">issues</a> in [func.wrap.func].</p>
27107<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
27108<p><b>Discussion:</b></p>
27109<p>
27110The class template <tt>std::function</tt> contains the following member
27111declarations:
27112</p>
27113
27114<blockquote><pre>// deleted overloads close possible hole in the type system
27115template&lt;class R2, class... ArgTypes2&gt;
27116  bool operator==(const function&lt;R2(ArgTypes2...)&gt;&amp;) = delete;
27117template&lt;class R2, class... ArgTypes2&gt;
27118  bool operator!=(const function&lt;R2(ArgTypes2...)&gt;&amp;) = delete;
27119</pre></blockquote>
27120
27121<p>
27122The leading comment here is part of the history of <tt>std::function</tt>, which
27123was introduced with <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2002/n1402.html#undefined_operators">N1402</a>.
27124During that time no explicit conversion functions existed, and the
27125"safe-bool" idiom (based on pointers-to-member) was a popular
27126technique. The only disadvantage of this idiom was that given two
27127objects <tt>f1</tt> and <tt>f2</tt> of type <tt>std::function</tt> the expression
27128</p>
27129
27130<blockquote><pre>f1 == f2;
27131</pre></blockquote>
27132
27133<p>
27134was well-formed, just because the built-in <tt>operator==</tt> for pointer to member
27135was considered after a single user-defined conversion. To fix this, an
27136overload set of <em>undefined</em> comparison functions was added,
27137such that overload resolution would prefer those ending up in a linkage error.
27138The new language facility of deleted functions provided a much better
27139diagnostic mechanism to fix this issue.
27140</p>
27141
27142<p>
27143The central point of this issue is, that with the replacement of the
27144safe-bool idiom by explicit conversion to bool the original "hole in the
27145type system" does no longer exist and therefore the comment is wrong and
27146the superfluous function definitions should be removed as well. An
27147explicit conversion function is considered in direct-initialization
27148situations only, which indirectly contain the so-called "contextual
27149conversion to bool" (4 [conv]/3). These conversions are not considered for
27150<tt>==</tt> or <tt>!=</tt> as defined by the core language.
27151</p>
27152
27153
27154<p><b>Proposed resolution:</b></p>
27155<p>
27156In 20.7.15.2 [func.wrap.func]/1, class function change as indicated:
27157</p>
27158
27159<blockquote><pre>// 20.7.15.2.3, function capacity:
27160explicit operator bool() const;
27161
27162<del>// deleted overloads close possible hole in the type system</del>
27163<del>template&lt;class R2, class... ArgTypes2&gt;</del>
27164  <del>bool operator==(const function&lt;R2(ArgTypes2...)&gt;&amp;) = delete;</del>
27165<del>template&lt;class R2, class... ArgTypes2&gt;</del>
27166  <del>bool operator!=(const function&lt;R2(ArgTypes2...)&gt;&amp;) = delete;</del>
27167</pre></blockquote>
27168
27169
27170
27171
27172
27173<hr>
27174<h3><a name="1241"></a>1241. unique_copy needs to require EquivalenceRelation</h3>
27175<p><b>Section:</b> 25.3.9 [alg.unique] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Ready">Tentatively Ready</a>
27176 <b>Submitter:</b> Daniel Kr�gler <b>Opened:</b> 2009-10-17  <b>Last modified:</b> 2009-10-31</p>
27177<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#alg.unique">issues</a> in [alg.unique].</p>
27178<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Tentatively%20Ready">Tentatively Ready</a> status.</p>
27179<p><b>Discussion:</b></p>
27180<p>
27181A lot of fixes were silently applied during concept-time and we should
27182not lose them again. The Requires clause of 25.3.9 [alg.unique]/5
27183doesn't mention that <tt>==</tt> and the predicate need to satisfy an
27184<tt>EquivalenceRelation</tt>, as it is correctly said for
27185<tt>unique</tt>. This was intentionally fixed during conceptification,
27186were we had:
27187</p>
27188
27189<blockquote><pre>template&lt;InputIterator InIter, class OutIter&gt;
27190  requires OutputIterator&lt;OutIter, RvalueOf&lt;InIter::value_type&gt;::type&gt;
27191        &amp;&amp; EqualityComparable&lt;InIter::value_type&gt;
27192        &amp;&amp; HasAssign&lt;InIter::value_type, InIter::reference&gt;
27193        &amp;&amp; Constructible&lt;InIter::value_type, InIter::reference&gt;
27194  OutIter unique_copy(InIter first, InIter last, OutIter result);
27195
27196template&lt;InputIterator InIter, class OutIter,
27197         EquivalenceRelation&lt;auto, InIter::value_type&gt; Pred&gt;
27198  requires OutputIterator&lt;OutIter, RvalueOf&lt;InIter::value_type&gt;::type&gt;
27199        &amp;&amp; HasAssign&lt;InIter::value_type, InIter::reference&gt;
27200        &amp;&amp; Constructible&lt;InIter::value_type, InIter::reference&gt;
27201        &amp;&amp; CopyConstructible&lt;Pred&gt;
27202  OutIter unique_copy(InIter first, InIter last, OutIter result, Pred pred);
27203</pre></blockquote>
27204
27205<p>
27206Note that EqualityComparable implied an equivalence relation.
27207</p>
27208
27209<p><i>[
27210N.B. <tt>adjacent_find</tt> was also specified to require
27211<tt>EquivalenceRelation</tt>, but that was considered as a defect in
27212concepts, see <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#1000">1000</a>
27213]</i></p>
27214
27215
27216<p><i>[
272172009-10-31 Howard adds:
27218]</i></p>
27219
27220
27221<blockquote>
27222Moved to Tentatively Ready after 5 positive votes on c++std-lib.
27223</blockquote>
27224
27225
27226
27227<p><b>Proposed resolution:</b></p>
27228<p>
27229Change 25.3.9 [alg.unique]/5 as indicated:
27230</p>
27231
27232<blockquote><pre>template&lt;class InputIterator, class OutputIterator&gt;
27233  OutputIterator
27234    unique_copy(InputIterator first, InputIterator last, OutputIterator result);
27235
27236template&lt;class InputIterator, class OutputIterator, class BinaryPredicate&gt;
27237  OutputIterator
27238    unique_copy(InputIterator first, InputIterator last,
27239                OutputIterator result, BinaryPredicate pred);
27240</pre>
27241<blockquote>
27242<i>Requires:</i> <ins>The comparison function shall be an equivalence
27243relation.</ins> The ranges <tt>[first,last)</tt> and
27244<tt>[result,result+(last-first))</tt> shall not overlap. The expression
27245<tt>*result = *first</tt> shall be valid. If neither
27246<tt>InputIterator</tt> nor <tt>OutputIterator</tt> meets the
27247requirements of forward iterator then the value type of
27248<tt>InputIterator</tt> shall be <tt>CopyConstructible</tt> (34) and
27249<tt>CopyAssignable</tt> (table 36). Otherwise <tt>CopyConstructible</tt>
27250is not required.
27251</blockquote>
27252</blockquote>
27253
27254
27255
27256
27257
27258<hr>
27259<h3><a name="1244"></a>1244. wait_*() in *future for synchronous functions</h3>
27260<p><b>Section:</b> 30.6 [futures] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
27261 <b>Submitter:</b> Detlef Vollmann <b>Opened:</b> 2009-10-22  <b>Last modified:</b> 2009-10-23</p>
27262<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#futures">issues</a> in [futures].</p>
27263<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
27264<p><b>Discussion:</b></p>
27265<p>
27266With the addition of <tt>async()</tt>, a <tt>future</tt> might be
27267associated with a function that is not running in a different thread but
27268is stored to by run synchronously on the <tt>get()</tt> call. It's not
27269clear what the <tt>wait()</tt> functions should do in this case.
27270</p>
27271
27272<p>
27273Suggested resolution:
27274</p>
27275
27276<p>
27277Throw an exception.
27278</p>
27279
27280
27281<p><b>Proposed resolution:</b></p>
27282
27283
27284
27285
27286
27287<hr>
27288<h3><a name="1245"></a>1245. <tt>std::hash&lt;string&gt;</tt> &amp; co</h3>
27289<p><b>Section:</b> 20.7.16 [unord.hash] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
27290 <b>Submitter:</b> Paolo Carlini <b>Opened:</b> 2009-10-22  <b>Last modified:</b> 2009-10-25</p>
27291<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#unord.hash">active issues</a> in [unord.hash].</p>
27292<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#unord.hash">issues</a> in [unord.hash].</p>
27293<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
27294<p><b>Discussion:</b></p>
27295<p>
27296In 20.7.16 [unord.hash], <tt>operator()</tt> is specified as
27297taking the argument by value. Moreover, it is said that <tt>operator()</tt> shall
27298not throw exceptions.
27299</p>
27300
27301<p>
27302However, for the specializations for class types, like <tt>string</tt>, <tt>wstring</tt>,
27303etc, the former requirement seems suboptimal from the performance point
27304of view (a specific PR has been filed about this in the GCC Bugzilla)
27305and, together with the latter requirement, hard if not impossible to
27306fulfill. It looks like pass by const reference should be allowed in such
27307cases.
27308</p>
27309
27310
27311<p><b>Proposed resolution:</b></p>
27312<p>
27313Add to 20.7.16 [unord.hash]/2:
27314</p>
27315
27316<blockquote>
27317<pre>namespace std {
27318  template &lt;class T&gt;
27319  struct hash : public std::unary_function&lt;T, std::size_t&gt; {
27320    std::size_t operator()(T val) const;
27321  };
27322}
27323</pre>
27324
27325<p>
27326The return value of <tt>operator()</tt> is unspecified, except that
27327equal arguments shall yield the same result. <tt>operator()</tt> shall
27328not throw exceptions. <ins>It is also unspecified whether
27329<tt>operator()</tt> of <tt>std::hash</tt> specializations for class
27330types takes its argument by value or const reference.</ins>
27331</p>
27332</blockquote>
27333
27334
27335
27336
27337
27338<hr>
27339<h3><a name="1246"></a>1246. <tt>vector::resize()</tt> missing efficiency guarantee</h3>
27340<p><b>Section:</b> 23.3.6.2 [vector.capacity] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
27341 <b>Submitter:</b> David Abrahams <b>Opened:</b> 2009-10-24  <b>Last modified:</b> 2009-10-25</p>
27342<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#vector.capacity">issues</a> in [vector.capacity].</p>
27343<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
27344<p><b>Discussion:</b></p>
27345<p>
27346If <tt>v</tt> is a <tt>vector</tt>, I think repeated calls to
27347<tt>v.resize( v.size() + 1 )</tt> should be amortized O(1), but it's not
27348clear that's true from the text of the standard:
27349</p>
27350
27351<blockquote><pre>void resize(size_type sz);
27352</pre>
27353<blockquote>
27354<i>Effects:</i> If <tt>sz &lt; size()</tt>, equivalent to <tt>erase(begin() + sz, end());</tt>. If
27355<tt>size() &lt; sz</tt>, appends <tt>sz - size()</tt> default constructed elements to the
27356sequence.
27357</blockquote>
27358</blockquote>
27359
27360<p>
27361Seems to me if we used <tt>push_back</tt> instead of appends, we might be giving
27362the guarantee I'd like.  Thoughts?
27363</p>
27364
27365
27366<p><b>Proposed resolution:</b></p>
27367<p>
27368In 23.3.6.2 [vector.capacity]/10, change
27369</p>
27370
27371<blockquote><pre>void resize(size_type sz);
27372</pre>
27373<blockquote>
27374<i>Effects:</i> If <tt>sz &lt; size()</tt>, equivalent to <tt>erase(begin() + sz, end());</tt>. If
27375<tt>size() &lt; sz</tt>, <del>appends <tt>sz - size()</tt> default constructed elements to the
27376sequence</del>
27377<ins>equivalent to <tt>sz - size()</tt> consecutive evaluations of <tt>push_back(T())</tt></ins>.
27378</blockquote>
27379</blockquote>
27380
27381
27382
27383
27384
27385
27386<hr>
27387<h3><a name="1247"></a>1247. <tt>auto_ptr</tt> is overspecified</h3>
27388<p><b>Section:</b> D.10.1 [auto.ptr] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#Review">Review</a>
27389 <b>Submitter:</b> Alisdair Meredith <b>Opened:</b> 2009-10-24  <b>Last modified:</b> 2009-11-06</p>
27390<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#auto.ptr">issues</a> in [auto.ptr].</p>
27391<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#Review">Review</a> status.</p>
27392<p><b>Discussion:</b></p>
27393<p>
27394This issue is extracted as the ongoing point-of-interest from earlier
27395issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-closed.html#463">463</a>.
27396</p>
27397
27398<p>
27399<tt>auto_ptr</tt> is overspecified as the <tt>auto_ptr_ref</tt>
27400implementation detail is formally specified, and the technique is
27401observable so workarounds for compiler defects can  cause a working
27402implementation of the primary <tt>auto_ptr</tt> template become
27403non-conforming.
27404</p>
27405
27406<p>
27407<tt>auto_ptr_ref</tt> is a documentation aid to describe a possible
27408mechanism to implement the class.  It should be marked exposition only,
27409as per similar classes, e.g., <tt>istreambuf_iterator::proxy</tt>
27410</p>
27411
27412<p><i>[
274132009-10-25 Daniel adds:
27414]</i></p>
27415
27416
27417<blockquote>
27418<p>
27419I wonder, whether the revised wording shouldn't be as straight as
27420for <tt>istream_buf</tt> by adding one further sentence:
27421</p>
27422
27423<blockquote>
27424An implementation is permitted to provide equivalent functionality without
27425providing a class with this name.
27426</blockquote>
27427</blockquote>
27428
27429<p><i>[
274302009-11-06 Alisdair adds Daniel's suggestion to the proposed wording.
27431]</i></p>
27432
27433
27434<p><i>[
274352009-11-06 Howard moves issue to Review.
27436]</i></p>
27437
27438
27439
27440
27441<p><b>Proposed resolution:</b></p>
27442<p>
27443Add the term "exposition only" in the following two places:
27444</p>
27445
27446<p>
27447Ammend D.10.1 [auto.ptr]p2:
27448</p>
27449
27450<blockquote>
27451<p>
27452<ins>The exposition only class </ins> <del>T</del><ins>t</ins>emplate <tt>auto_ptr_ref</tt>
27453holds a reference to an <tt>auto_ptr</tt>. It is used by the
27454<tt>auto_ptr</tt> conversions to allow <tt>auto_ptr</tt> objects to be
27455passed to and returned from functions.
27456<ins>An implementation is permitted to provide equivalent functionality
27457without providing a class with this name.</ins>
27458</p>
27459
27460<blockquote><pre>namespace std {
27461 template &lt;class Y&gt; struct auto_ptr_ref { }; <ins>// exposition only</ins>
27462</pre></blockquote>
27463</blockquote>
27464
27465
27466
27467
27468
27469<hr>
27470<h3><a name="1249"></a>1249. basic_ios default ctor</h3>
27471<p><b>Section:</b> 27.5.4.1 [basic.ios.cons] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
27472 <b>Submitter:</b> Martin Sebor <b>Opened:</b> 2009-10-25  <b>Last modified:</b> 2009-10-26</p>
27473<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#basic.ios.cons">issues</a> in [basic.ios.cons].</p>
27474<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
27475<p><b>Discussion:</b></p>
27476<p>
27477The basic_ios default ctor is required to leave the objects members
27478uninitialized (see below). The paragraph says the object must be
27479initialized by calling basic_ios::init() before it's destroyed by
27480I can't find a requirement that it be initialized before calling
27481any of the class other member functions. Am I not looking in the
27482right place or that an issue?
27483</p>
27484
27485<p><i>[
274862009-10-25 Daniel adds:
27487]</i></p>
27488
27489
27490<blockquote>
27491<p>
27492I agree, that your wording makes that clearer, but suggest to write
27493</p>
27494
27495<blockquote>
27496... calling <tt>basic_ios::init<del>()</del></tt> before ...
27497</blockquote>
27498
27499<p>
27500Doing so, I recommend to adapt that of <tt>ios_base();</tt> as well, where
27501we have:
27502</p>
27503
27504<blockquote>
27505<i>Effects:</i> Each <tt>ios_base</tt> member has an indeterminate value
27506after construction. These members shall be initialized by calling
27507<tt>basic_ios::init</tt>. If an <tt>ios_base</tt> object is destroyed
27508before these initializations have taken place, the behavior is
27509undefined.
27510</blockquote>
27511</blockquote>
27512
27513
27514
27515<p><b>Proposed resolution:</b></p>
27516<p>
27517Change 27.5.2.7 [ios.base.cons] p1:
27518</p>
27519
27520<blockquote><pre>ios_base();
27521</pre>
27522<blockquote>
27523<i>Effects:</i> Each <tt>ios_base</tt> member has an indeterminate value
27524after construction. <del>These</del> <ins>The object's</ins> members shall be initialized by calling
27525<tt>basic_ios::init</tt> <ins>before the object's first use or before
27526 it is destroyed, whichever comes first; otherwise the behavior
27527 is undefined.</ins>. <del>If an <tt>ios_base</tt> object is destroyed
27528before these initializations have taken place, the behavior is
27529undefined.</del>
27530</blockquote>
27531</blockquote>
27532
27533<p>
27534Change 27.5.4.1 [basic.ios.cons] p2:
27535</p>
27536
27537<blockquote><pre>basic_ios();
27538</pre>
27539<blockquote>
27540<i>Effects:</i> Constructs an object of class <tt>basic_ios</tt>
27541(27.5.2.7) leaving its member objects uninitialized. The object shall be
27542initialized by calling <del>its</del>
27543<tt><ins>basic_ios::</ins>init</tt> <ins>before its first
27544use or before it is destroyed, whichever comes first; otherwise the
27545behavior is undefined.</ins> <del>member function. If it is destroyed
27546before it has been initialized the behavior is undefined.</del>
27547</blockquote>
27548</blockquote>
27549
27550
27551
27552
27553
27554<hr>
27555<h3><a name="1250"></a>1250. <tt>&lt;bitset&gt;</tt> still overspecified</h3>
27556<p><b>Section:</b> 20.3.7 [template.bitset] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
27557 <b>Submitter:</b> Martin Sebor <b>Opened:</b> 2009-10-29  <b>Last modified:</b> 2009-10-29</p>
27558<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#template.bitset">active issues</a> in [template.bitset].</p>
27559<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#template.bitset">issues</a> in [template.bitset].</p>
27560<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
27561<p><b>Discussion:</b></p>
27562<p>
27563Issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1227">1227</a> &#8212; <tt>&lt;bitset&gt;</tt> synopsis overspecified makes the observation
27564that <tt>std::bitset</tt>, and in fact the whole library, may be implemented
27565without needing to <tt>#include &lt;stdexcept&gt;</tt> in any library header. The
27566proposed resolution removes the <tt>#include &lt;stdexcept&gt;</tt> directive from
27567the header.
27568</p>
27569
27570<p>
27571I'd like to add that the <tt>&lt;bitset&gt;</tt> header (as well as the rest of
27572the library) has also been implemented without #including the
27573<tt>&lt;cstddef&gt;</tt> header in any library header. In the case of <tt>std::bitset</tt>,
27574the template is fully usable (i.e., it may be instantiated and all
27575its member functions may be used) without ever mentioning <tt>size_t</tt>.
27576In addition, just like no library header except for <tt>&lt;bitset&gt;</tt>
27577<tt>#includes &lt;stdexcept&gt;</tt> in its synopsis, no header but <tt>&lt;bitset&gt;</tt>
27578<tt>#includes &lt;cstddef&gt;</tt> either.
27579</p>
27580
27581<p>
27582Thus I suggest that the <tt>#include &lt;cstddef&gt;</tt> directive be similarly
27583removed from the synopsis of <tt>&lt;bitset&gt;</tt>.
27584</p>
27585
27586
27587<p><b>Proposed resolution:</b></p>
27588<p>
27589Change 20.3.7 [template.bitset]:
27590</p>
27591
27592<blockquote><pre><del>#include &lt;cstddef&gt;        // for size_t</del>
27593#include &lt;string&gt;
27594#include &lt;iosfwd&gt;         // for istream, ostream
27595namespace std {
27596...
27597</pre></blockquote>
27598
27599
27600
27601
27602
27603<hr>
27604<h3><a name="1251"></a>1251. move constructing <tt>basic_stringbuf</tt></h3>
27605<p><b>Section:</b> 27.8.1.1 [stringbuf.cons] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
27606 <b>Submitter:</b> Martin Sebor <b>Opened:</b> 2009-10-29  <b>Last modified:</b> 2009-10-29</p>
27607<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#stringbuf.cons">issues</a> in [stringbuf.cons].</p>
27608<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
27609<p><b>Discussion:</b></p>
27610<p>
27611I just came across issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1204">1204</a> -- Global permission to move, which
27612seems to address the concern raised by the example in c++std-lib-25030.
27613</p>
27614<p>
27615IIUC, the example violates the permission to assume that arguments
27616bound to rvalue references are unnamed temporaries granted to
27617implementations by the resolution of issue <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1204">1204</a> - Global permission
27618to move.
27619</p>
27620
27621<p>
27622I.e., the <tt>ostringstream(ostringstream &amp;&amp;rhs)</tt> ctor can leave the <tt>rhs</tt>
27623pointers pointing to the newly constructed object's buffer just as
27624long as the dtor doesn't change or invalidate the buffer. The caller
27625may not make any assumptions about rhs after the move beyond it being
27626safe to destroy or reassign.
27627</p>
27628
27629<p>
27630So unless I misunderstood something, I still think the <tt>basic_stringbuf</tt>
27631move ctor is overspecified. Specifically, I think the third sentence
27632in the Effects clause and the last 6 bullets in the Postconditions
27633clause can, and IMO should, be stricken.
27634</p>
27635
27636
27637<p><b>Proposed resolution:</b></p>
27638<p>
27639Strike from 27.8.1.1 [stringbuf.cons]:
27640</p>
27641
27642<blockquote><pre>basic_stringbuf(basic_stringbuf&amp;&amp; rhs);
27643</pre>
27644<blockquote>
27645<p>
27646<i>Effects:</i> Move constructs from the rvalue <tt>rhs</tt>. It is
27647implementation-defined whether the sequence pointers in <tt>*this</tt>
27648(<tt>eback()</tt>, <tt>gptr()</tt>, <tt>egptr()</tt>, <tt>pbase()</tt>,
27649<tt>pptr()</tt>, <tt>epptr()</tt>) obtain the values which <tt>rhs</tt>
27650had. <del>Whether they do or not, <tt>*this</tt> and <tt>rhs</tt> reference
27651separate buffers (if any at all) after the construction.</del> The openmode,
27652locale and any other state of <tt>rhs</tt> is also copied.
27653</p>
27654
27655<p>
27656<i>Postconditions:</i> Let <tt>rhs_p</tt> refer to the state of
27657<tt>rhs</tt> just prior to this construction and let <tt>rhs_a</tt>
27658referto the state of <tt>rhs</tt> just after this construction.
27659</p>
27660<ul>
27661<li>
27662<tt>str() == rhs_p.str()</tt>
27663</li>
27664<li>
27665<tt>gptr() - eback() == rhs_p.gptr() - rhs_p.eback()</tt>
27666</li>
27667<li>
27668<tt>egptr() - eback() == rhs_p.egptr() - rhs_p.eback()</tt>
27669</li>
27670<li>
27671<tt>pptr() - pbase() == rhs_p.pptr() - rhs_p.pbase()</tt>
27672</li>
27673<li>
27674<tt>epptr() - pbase() == rhs_p.epptr() - rhs_p.pbase()</tt>
27675</li>
27676<li><del>
27677if <tt>(eback()) eback() != rhs_a.eback()</tt>
27678</del></li>
27679<li><del>
27680if <tt>(gptr()) gptr() != rhs_a.gptr()</tt>
27681</del></li>
27682<li><del>
27683if <tt>(egptr()) egptr() != rhs_a.egptr()</tt>
27684</del></li>
27685<li><del>
27686if <tt>(pbase()) pbase() != rhs_a.pbase()</tt>
27687</del></li>
27688<li><del>
27689if <tt>(pptr()) pptr() != rhs_a.pptr()</tt>
27690</del></li>
27691<li><del>
27692if <tt>(epptr()) epptr() != rhs_a.epptr()</tt>
27693</del></li>
27694</ul>
27695</blockquote>
27696</blockquote>
27697
27698
27699
27700
27701
27702
27703<hr>
27704<h3><a name="1252"></a>1252. <tt>wbuffer_convert::state_type</tt> inconsistency</h3>
27705<p><b>Section:</b> 22.3.3.2.3 [conversions.buffer] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
27706 <b>Submitter:</b> Bo Persson  <b>Opened:</b> 2009-10-21  <b>Last modified:</b> 2009-10-31</p>
27707<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
27708<p><b>Discussion:</b></p>
27709<p>
27710The synopisis for <tt>wbuffer_convert</tt> 22.3.3.2.3 [conversions.buffer]/2 contains
27711</p>
27712
27713<blockquote><pre>typedef typename Tr::state_type   state_type; 
27714</pre></blockquote>
27715
27716<p>
27717making <tt>state_type</tt> a synonym for (possibly) some
27718<tt>char_traits&lt;x&gt;::state_type</tt>. 
27719</p>
27720
27721<p>
27722However, in paragraph 9 of the same section, we have 
27723</p>
27724
27725<blockquote><pre>typedef typename Codecvt::state_type state_type;
27726</pre>
27727
27728<blockquote>
27729The type shall be a synonym for <tt>Codecvt::state_type</tt>.
27730</blockquote>
27731</blockquote>
27732
27733<p>
27734From what I can see, it might be hard to implement
27735<tt>wbuffer_convert</tt> if the types were not both
27736<tt>std::mbstate_t</tt>, but I cannot find a requirement that they must
27737be the same type.
27738</p>
27739
27740
27741<p><b>Proposed resolution:</b></p>
27742
27743
27744
27745
27746
27747<hr>
27748<h3><a name="1253"></a>1253. invalidation of iterators and <tt>emplace</tt> vs. <tt>insert</tt> inconsistence in assoc. containers</h3>
27749<p><b>Section:</b> 23.2.4 [associative.reqmts] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
27750 <b>Submitter:</b> Boris Du&#353;ek <b>Opened:</b> 2009-10-24  <b>Last modified:</b> 2009-10-31</p>
27751<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#associative.reqmts">active issues</a> in [associative.reqmts].</p>
27752<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#associative.reqmts">issues</a> in [associative.reqmts].</p>
27753<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
27754<p><b>Discussion:</b></p>
27755<p>
27756In the latest published draft
27757<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2960.pdf">N2960</a>,
27758section 23.2.4 [associative.reqmts], paragraph 8, it is specifies
27759that that <tt>insert</tt> does not invalidate any iterators. As per
2776023.2.1 [container.requirements.general], paragraph 12, this holds
27761true not only for <tt>insert</tt>, but <tt>emplace</tt> as well. This
27762gives the <tt>insert</tt> member a special treatment w.r.t.
27763<tt>emplace</tt> member in 23.2.4 [associative.reqmts], par. 8,
27764since both modify the container. For the sake of consistency, in 23.2.4 [associative.reqmts], par. 8: either reference to
27765<tt>insert</tt> should be removed (i.e. count on 23.2.1 [container.requirements.general], par. 12), or reference to
27766<tt>emplace</tt> be added (i.e. mention all members of assoc. containers
27767that modify it).
27768</p>
27769
27770
27771<p><b>Proposed resolution:</b></p>
27772<p>
27773</p>
27774
27775
27776
27777
27778
27779<hr>
27780<h3><a name="1254"></a>1254. Misleading sentence in <tt>vector&lt;bool&gt;::flip</tt></h3>
27781<p><b>Section:</b> 23.3.7 [vector.bool] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
27782 <b>Submitter:</b> Christopher Jefferson <b>Opened:</b> 2009-11-01  <b>Last modified:</b> 2009-11-01</p>
27783<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#vector.bool">issues</a> in [vector.bool].</p>
27784<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
27785<p><b>Discussion:</b></p>
27786<p>
27787The effects of <tt>vector&lt;bool&gt;::flip</tt> has the line:
27788</p>
27789
27790<blockquote>
27791It is unspecified whether the function has any effect on allocated but
27792unused bits.
27793</blockquote>
27794
27795<p>
27796While this is technically true, it is misleading, as any member function
27797in any standard container may change unused but allocated memory. Users
27798can never observe such changes as it would also be undefined behaviour
27799to read such memory.
27800</p>
27801
27802
27803<p><b>Proposed resolution:</b></p>
27804<p>
27805Strike second sentence from the definition of <tt>vector&lt;bool&gt;::flip()</tt>,
2780623.3.7 [vector.bool], paragraph 5.
27807</p>
27808
27809<blockquote>
27810<i>Effects:</i> Replaces each element in the container with its complement.
27811<del>It is unspecified whether the function has any effect on allocated
27812but unused bits.</del>
27813</blockquote>
27814
27815
27816
27817
27818
27819<hr>
27820<h3><a name="1255"></a>1255. <tt>declval</tt> should be added to the library</h3>
27821<p><b>Section:</b> 20.3 [utility] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
27822 <b>Submitter:</b> Daniel Kr�gler <b>Opened:</b> 2009-11-03  <b>Last modified:</b> 2009-11-04</p>
27823<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
27824<p><b>Discussion:</b></p>
27825<p>
27826During the Santa Cruz meeting it was decided to split off the provision
27827of the library utility <tt>value()</tt> proposed in <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2979.html">N2979</a>
27828from the concrete request of the
27829<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2939.html#uk300">UK 300</a>
27830comment.
27831The provision of a new library component that allows the production of
27832values in unevaluated expressions is considered as important
27833to realize constrained templates in C++0x where concepts are not
27834available.
27835</p>
27836
27837<p>
27838The following proposed resolution is an improvement over that suggested in
27839<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2958.html">N2958</a>,
27840because the proposed component can now be defined without loss of
27841general usefulness and any <i>use</i> by user-code will make the program ill-formed.
27842A possible prototype implementation that satisfies the core language
27843requirements
27844can be written as:
27845</p>
27846
27847<blockquote><pre>template&lt;class T&gt;
27848  struct declval_protector {
27849    static const bool stop = false;
27850    static typename std::add_rvalue_reference&lt;T&gt;::type delegate(); <font color="#c80000">// undefined</font>
27851  };
27852
27853template&lt;class T&gt;
27854typename std::add_rvalue_reference&lt;T&gt;::type declval() {
27855  static_assert(declval_protector&lt;T&gt;::stop, "declval() must not be used!");
27856  return declval_protector&lt;T&gt;::delegate();
27857}
27858</pre></blockquote>
27859
27860<p>
27861Further-on the earlier suggested name <tt>value()</tt> has been changed to <tt>declval()</tt>
27862after discussions with committee members.
27863</p>
27864
27865<p>
27866Finally the suggestion shown below demonstrates that it can simplify
27867existing standard wording by directly using it in the library
27868specification, and that it also improves an overlooked corner case for
27869<tt>common_type</tt> by adding support for <tt>cv void</tt>.
27870</p>
27871
27872
27873<p><b>Proposed resolution:</b></p>
27874<p><i>[
27875The following edit assumes that the earlier component identity
27876has been removed as part of applying the solution of <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#939">939</a>,
27877<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2951.html">N2951</a>,
27878and
27879<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2984.html">N2984</a>.
27880Note that the proposal does not depend on this application,
27881but it just simplifies the editorial representation
27882]</i></p>
27883
27884
27885<ol>
27886<li>
27887<p>
27888Change 20.3 [utility], header <tt>&lt;utility&gt;</tt> synopsis
27889as indicated:
27890</p>
27891
27892<blockquote><pre>// 20.3.2, forward/move:
27893template &lt;class T, class U&gt; T&amp;&amp; forward(U&amp;&amp; u);;
27894template &lt;class T&gt; typename remove_reference&lt;T&gt;::type&amp;&amp; move(T&amp;&amp;);
27895
27896<ins>// 20.3.3, declval:</ins>
27897<ins>template &lt;class T&gt; typename add_rvalue_reference&lt;T&gt;::type declval(); // for unused context</ins>
27898</pre></blockquote>
27899</li>
27900
27901<li>
27902<p>
27903Immediately after the current section 20.3.3 [forward] insert a
27904new section:
27905</p>
27906<p>
27907<ins>20.3.3 Function template declval [declval]</ins>
27908</p>
27909<p>
27910<ins>The library provides the function template <tt>declval</tt> to simplify
27911the definition of expressions in
27912unevaluated and unused contexts (3.2 [basic.def.odr], 5 [expr]). The
27913template parameter <tt>T</tt> of <tt>declval</tt> may
27914be an incomplete type.</ins>
27915</p>
27916
27917<pre><ins>template &lt;class T&gt; typename add_rvalue_reference&lt;T&gt;::type declval(); // for unused context</ins>
27918</pre>
27919
27920<blockquote>
27921<p>
27922<ins><i>Remarks:</i> If this function is used according to 3.2 [basic.def.odr],
27923the program shall be ill-formed.</ins>
27924</p>
27925
27926<p>
27927<ins>[<i>Example:</i></ins>
27928</p>
27929
27930<blockquote><pre><ins>
27931template&lt;class To, class From&gt;
27932decltype(static_cast&lt;To&gt;(declval&lt;From&gt;())) convert(From&amp;&amp;);
27933</ins></pre></blockquote>
27934
27935<p>
27936<ins>
27937declares a function template <tt>convert</tt>, which does only participate in
27938overloading, if the type <tt>From</tt> can be
27939explicitly casted to type <tt>To</tt> &#8212; <i>end example</i>]</ins>
27940</p>
27941</blockquote>
27942
27943</li>
27944
27945<li>
27946<p>
27947This bullet just makes clear that after applying <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2984.html">N2984</a>, the changes in 20.6.4.3 [meta.unary.prop], before
27948table Type property queries should <em>not</em> use <tt>declval</tt>,
27949because the well-formedness requirement of the specification of
27950<tt>is_constructible</tt> would become more complicated, because we
27951would need to make sure that the expression <i>CE</i> is checked in an
27952unevaluated context.
27953</p>
27954</li>
27955
27956<li>
27957<p>
27958Also 20.6.5 [meta.rel]/4 is not modified similar to the previous bullet,
27959because with
27960the stricter requirements of not using <tt>declval()</tt> the well-formedness condition
27961would be harder to specify. The following changes are only editorial ones (e.g.
27962the removal of the duplicate declaration of <tt>create()</tt>):
27963</p>
27964
27965<blockquote>
27966<p>
27967Given the following function prototype:
27968</p>
27969
27970<blockquote><pre>template &lt;class T&gt;
27971  typename add_rvalue_reference&lt;T&gt;::type create();
27972</pre></blockquote>
27973
27974<p>
27975the predicate condition for a template specialization
27976<tt>is_convertible&lt;From, To&gt;</tt> shall be satisfied if and only
27977if the return expression in the following code would be well-formed,
27978including any
27979im<del>m</del>plicit conversions to the return type of the function:
27980</p>
27981
27982<blockquote><pre><del>template &lt;class T&gt;
27983typename add_rvalue_reference&lt;T&gt;::type create();</del>
27984To test() {
27985  return create&lt;From&gt;();
27986}
27987</pre></blockquote>
27988</blockquote>
27989</li>
27990
27991<li>
27992<p>
27993Change the entry in column "Comments" for <tt>common_type</tt> in Table 51 &#8212;
27994Other transformations (20.6.7 [meta.trans.other]):
27995</p>
27996
27997<p><i>[
27998NB: This wording change extends the type domain of <tt>common_type</tt> for <tt>cv
27999void =&gt; cv void</tt> transformations and thus makes <tt>common_type</tt> usable for
28000all binary type combinations that are supported by <tt>is_convertible</tt>
28001]</i></p>
28002
28003
28004<blockquote>
28005The member typedef <tt>type</tt> shall be defined as set out below. All
28006types in the parameter pack <tt>T</tt> shall be complete <ins>or
28007(possibly cv-qualified) <tt>void</tt></ins>. A program may specialize
28008this trait if at least one template parameter in the specialization is a
28009user-defined type. [<i>Note:</i> Such specializations are needed when
28010only explicit conversions are desired among the template arguments.
28011&#8212; <i>end note</i>]
28012</blockquote>
28013</li>
28014
28015<li>
28016<p>
28017Change 20.6.7 [meta.trans.other]/3 as indicated:
28018</p>
28019
28020<p><i>[
28021NB: This wording change is more than an editorial simplification of
28022the definition of <tt>common_type</tt>: It also extends its usefulness for <tt>cv
28023void</tt> types as outlined above
28024]</i></p>
28025
28026
28027<blockquote>
28028<p>
28029The nested typedef <tt>common_type::type</tt> shall be defined as follows:
28030</p>
28031
28032<blockquote>
28033<p>
28034[..]
28035</p>
28036<pre>template &lt;class T, class U&gt;
28037struct common_type&lt;T, U&gt; {
28038<del>private:
28039  static T&amp;&amp; __t();
28040  static U&amp;&amp; __u();
28041public:</del>
28042  typedef decltype(true ? <del>__t</del><ins>declval&lt;T&gt;</ins>() : <del>__u</del><ins>declval&lt;U&gt;</ins>()) type;
28043};
28044</pre>
28045</blockquote>
28046</blockquote>
28047</li>
28048</ol>
28049
28050
28051
28052
28053
28054
28055<hr>
28056<h3><a name="1256"></a>1256. <tt>weak_ptr</tt> comparison functions should be removed</h3>
28057<p><b>Section:</b> 20.8.15.3 [util.smartptr.weak] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
28058 <b>Submitter:</b> Daniel Kr�gler <b>Opened:</b> 2009-11-04  <b>Last modified:</b> 2009-11-04</p>
28059<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
28060<p><b>Discussion:</b></p>
28061<p>
28062Additional to the necessary cleanup of the description of the the
28063<tt>weak_ptr</tt> component from 20.8.15.3 [util.smartptr.weak]
28064described in <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#1231">1231</a> it turns out that the currently deleted
28065comparison functions of <tt>weak_ptr</tt> are not needed at all: There
28066is no safe-bool conversion from <tt>weak_ptr</tt>, and it won't silently
28067chose a conversion to <tt>shared_ptr</tt>.
28068</p>
28069
28070
28071<p><b>Proposed resolution:</b></p>
28072<p>
28073Change 20.8.15.3 [util.smartptr.weak]/1 as indicated:
28074</p>
28075
28076<blockquote><pre>namespace std {
28077template&lt;class T&gt; class weak_ptr {
28078public:
28079...
28080  <del>// comparisons</del>
28081  <del>template&lt;class Y&gt; bool operator&lt;(weak_ptr&lt;Y&gt; const&amp;) const = delete;</del>
28082  <del>template&lt;class Y&gt; bool operator&lt;=(weak_ptr&lt;Y&gt; const&amp;) const = delete;</del>
28083  <del>template&lt;class Y&gt; bool operator&gt;(weak_ptr&lt;Y&gt; const&amp;) const = delete;</del>
28084  <del>template&lt;class Y&gt; bool operator&gt;=(weak_ptr&lt;Y&gt; const&amp;) const = delete;</del>
28085};
28086...
28087</pre></blockquote>
28088
28089
28090
28091
28092
28093<hr>
28094<h3><a name="1257"></a>1257. Header &lt;ios&gt; still contains a <code>concept_map</code></h3>
28095<p><b>Section:</b> 27.5 [iostreams.base] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
28096 <b>Submitter:</b> Beman Dawes <b>Opened:</b> 2009-11-04  <b>Last modified:</b> 2009-11-04</p>
28097<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#iostreams.base">issues</a> in [iostreams.base].</p>
28098<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
28099<p><b>Discussion:</b></p>
28100<p>
28101The current WP still contains a <tt>concept_map</tt>.
28102</p>
28103
28104
28105<p><b>Proposed resolution:</b></p>
28106<p>
28107Change Iostreams base classes 27.5 [iostreams.base], Header &lt;ios&gt; synopsis, 
28108as indicated:
28109</p>
28110
28111<blockquote><pre><del>concept_map ErrorCodeEnum&lt;io_errc&gt; { };</del>
28112<ins>template &lt;&gt; struct is_error_code_enum&lt;io_errc&gt; : true_type { }</ins>
28113error_code make_error_code(io_errc e);
28114error_condition make_error_condition(io_errc e);
28115const error_category&amp; iostream_category();
28116</pre></blockquote>
28117
28118
28119
28120
28121
28122
28123<hr>
28124<h3><a name="1258"></a>1258. std::function Effects clause impossible to satisfy</h3>
28125<p><b>Section:</b> 20.7.15.2.2 [func.wrap.func.mod] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
28126 <b>Submitter:</b> Daniel Kr�gler <b>Opened:</b> 2009-11-05  <b>Last modified:</b> 2009-11-05</p>
28127<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
28128<p><b>Discussion:</b></p>
28129<p>
28130As of 20.7.15.2.2 [func.wrap.func.mod]/2+ we have the following
28131prototype description:
28132</p>
28133
28134<blockquote><pre>template&lt;class F, Allocator Alloc&gt;
28135  requires Callable&lt;F, ArgTypes...&gt;
28136    &amp;&amp; Convertible&lt;Callable&lt;F, ArgTypes...&gt;::result_type, R&gt;
28137  void assign(F, const Alloc&amp;);
28138</pre>
28139<blockquote>
28140<i>Effects:</i> <tt>function(f, a).swap(*this)</tt>
28141</blockquote>
28142</blockquote>
28143
28144<p>
28145Two things: First the concept debris needs to be removed, second and
28146much more importantly, the effects clause is now impossible to satisfy,
28147because there is no constructor that would match the parameter sequence
28148(<tt>FunctionObject</tt>, <tt>Allocator</tt>) [plus the fact that no
28149<tt>f</tt> and no <tt>a</tt> is part of the signature]. The most
28150probable candidate is
28151</p>
28152
28153<blockquote><pre>template&lt;class F, class A&gt; function(allocator_arg_t, const A&amp;, F);
28154</pre></blockquote>
28155
28156<p>
28157and the effects clause needs to be adapted to use this signature.
28158</p>
28159
28160
28161<p><b>Proposed resolution:</b></p>
28162<p>
28163Change in 20.7.15.2.2 [func.wrap.func.mod] the complete prototype description as
28164indicated
28165</p>
28166<p><i>[
28167Question to
28168the editor: Shouldn't there a paragraph number in front of the Effects clause?
28169]</i></p>
28170
28171
28172<blockquote><pre><del>template&lt;class F, Allocator Alloc&gt;
28173  requires Callable&lt;F, ArgTypes...&gt;
28174    &amp;&amp; Convertible&lt;Callable&lt;F, ArgTypes...&gt;::result_type, R&gt;
28175  void assign(F, const Alloc&amp;);</del>
28176<ins>template&lt;class F, class A&gt; void assign(F f, const A&amp; a);</ins>
28177</pre>
28178<blockquote>
28179<ins>3</ins> <i>Effects:</i> <tt>function(<del>f, a</del><ins>allocator_arg, a,
28180f</ins>).swap(*this)</tt>
28181</blockquote>
28182</blockquote>
28183
28184
28185
28186
28187
28188<hr>
28189<h3><a name="1259"></a>1259. Should initializer-list constructors move elements?</h3>
28190<p><b>Section:</b> 23.2.3 [sequence.reqmts] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
28191 <b>Submitter:</b> Sean Hunt <b>Opened:</b> 2009-11-05  <b>Last modified:</b> 2009-11-06</p>
28192<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#sequence.reqmts">active issues</a> in [sequence.reqmts].</p>
28193<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#sequence.reqmts">issues</a> in [sequence.reqmts].</p>
28194<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
28195<p><b>Discussion:</b></p>
28196<p>
28197According to 23.2.3 [sequence.reqmts], <tt>X(il)</tt> is
28198equivalent to <tt>X(il.begin(), il.end())</tt>. Should it instead be
28199equivalent to <tt>X(move_iterator(il.begin()),
28200move_iterator(il.end()))</tt> so that needless copies are not made? This
28201doesn't seem ideal either - it may make more sense to provide two
28202overloads for the constructor, one for move and one for copy.
28203</p>
28204
28205
28206<p><b>Proposed resolution:</b></p>
28207<p>
28208</p>
28209
28210
28211
28212
28213
28214<hr>
28215<h3><a name="1260"></a>1260. <tt>is_constructible&lt;int*,void*&gt;</tt> reports true</h3>
28216<p><b>Section:</b> 20.6.4.3 [meta.unary.prop] <b>Status:</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#New">New</a>
28217 <b>Submitter:</b> Peter Dimov <b>Opened:</b> 2009-11-07  <b>Last modified:</b> 2009-11-08</p>
28218<p><b>View other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index-open.html#meta.unary.prop">active issues</a> in [meta.unary.prop].</p>
28219<p><b>View all other</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-index.html#meta.unary.prop">issues</a> in [meta.unary.prop].</p>
28220<p><b>View all issues with</b> <a href="http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-status.html#New">New</a> status.</p>
28221<p><b>Discussion:</b></p>
28222<p>
28223The specification of <tt>is_constructible&lt;T,Args...&gt;</tt> in
28224<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n3000.pdf">N3000</a>
28225uses
28226</p>
28227
28228<blockquote><pre>static_cast&lt;T&gt;(create&lt;Args&gt;()...)
28229</pre></blockquote>
28230
28231<p>
28232for the one-argument case, but <tt>static_cast</tt> also permits
28233unwanted conversions such as <tt>void*</tt> to <tt>T*</tt> and
28234<tt>Base*</tt> to <tt>Derived*</tt>.
28235</p>
28236
28237
28238<p><b>Proposed resolution:</b></p>
28239<p>
28240Change 20.6.4.3 [meta.unary.prop], p6:
28241</p>
28242
28243<blockquote>
28244<p>
28245the predicate condition for a template specialization
28246<tt>is_constructible&lt;T, Args&gt;</tt> shall be satisfied, if and only
28247if the following <del>expression <i>CE</i></del> <ins>variable
28248definition</ins> would be well-formed:
28249</p>
28250
28251<ul>
28252<li>
28253<p>
28254if <tt>sizeof...(Args) == <ins>0</ins> <del>1</del></tt><del>, the expression</del>:
28255</p>
28256<blockquote><pre><del>static_cast&lt;T&gt;(create&lt;Args&gt;()...)</del>
28257<ins>T t;</ins>
28258</pre></blockquote>
28259</li>
28260<li>
28261<p>
28262otherwise <del>the expression</del>:
28263</p>
28264<blockquote><pre>T<ins> t</ins>(create&lt;Args&gt;()...);
28265</pre></blockquote>
28266</li>
28267</ul>
28268</blockquote>
28269
28270
28271
28272
28273
28274</body></html>