1// String based streams -*- C++ -*-
2
3// Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
4// 2006, 2007, 2009
5// Free Software Foundation, Inc.
6//
7// This file is part of the GNU ISO C++ Library.  This library is free
8// software; you can redistribute it and/or modify it under the
9// terms of the GNU General Public License as published by the
10// Free Software Foundation; either version 3, or (at your option)
11// any later version.
12
13// This library is distributed in the hope that it will be useful,
14// but WITHOUT ANY WARRANTY; without even the implied warranty of
15// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16// GNU General Public License for more details.
17
18// Under Section 7 of GPL version 3, you are granted additional
19// permissions described in the GCC Runtime Library Exception, version
20// 3.1, as published by the Free Software Foundation.
21
22// You should have received a copy of the GNU General Public License and
23// a copy of the GCC Runtime Library Exception along with this program;
24// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
25// <http://www.gnu.org/licenses/>.
26
27/** @file sstream.tcc
28 *  This is an internal header file, included by other library headers.
29 *  You should not attempt to use it directly.
30 */
31
32//
33// ISO C++ 14882: 27.7  String-based streams
34//
35
36#ifndef _SSTREAM_TCC
37#define _SSTREAM_TCC 1
38
39#pragma GCC system_header
40
41_GLIBCXX_BEGIN_NAMESPACE(std)
42
43  template <class _CharT, class _Traits, class _Alloc>
44    typename basic_stringbuf<_CharT, _Traits, _Alloc>::int_type
45    basic_stringbuf<_CharT, _Traits, _Alloc>::
46    pbackfail(int_type __c)
47    {
48      int_type __ret = traits_type::eof();
49      if (this->eback() < this->gptr())
50	{
51	  // Try to put back __c into input sequence in one of three ways.
52	  // Order these tests done in is unspecified by the standard.
53	  const bool __testeof = traits_type::eq_int_type(__c, __ret);
54	  if (!__testeof)
55	    {
56	      const bool __testeq = traits_type::eq(traits_type::
57						    to_char_type(__c),
58						    this->gptr()[-1]);	  
59	      const bool __testout = this->_M_mode & ios_base::out;
60	      if (__testeq || __testout)
61		{
62		  this->gbump(-1);
63		  if (!__testeq)
64		    *this->gptr() = traits_type::to_char_type(__c);
65		  __ret = __c;
66		}
67	    }
68	  else
69	    {
70	      this->gbump(-1);
71	      __ret = traits_type::not_eof(__c);
72	    }
73	}
74      return __ret;
75    }
76
77  template <class _CharT, class _Traits, class _Alloc>
78    typename basic_stringbuf<_CharT, _Traits, _Alloc>::int_type
79    basic_stringbuf<_CharT, _Traits, _Alloc>::
80    overflow(int_type __c)
81    {
82      const bool __testout = this->_M_mode & ios_base::out;
83      if (__builtin_expect(!__testout, false))
84	return traits_type::eof();
85
86      const bool __testeof = traits_type::eq_int_type(__c, traits_type::eof());
87      if (__builtin_expect(__testeof, false))
88	return traits_type::not_eof(__c);
89
90      const __size_type __capacity = _M_string.capacity();
91      const __size_type __max_size = _M_string.max_size();
92      const bool __testput = this->pptr() < this->epptr();
93      if (__builtin_expect(!__testput && __capacity == __max_size, false))
94	return traits_type::eof();
95
96      // Try to append __c into output sequence in one of two ways.
97      // Order these tests done in is unspecified by the standard.
98      const char_type __conv = traits_type::to_char_type(__c);
99      if (!__testput)
100	{
101	  // NB: Start ostringstream buffers at 512 chars.  This is an
102	  // experimental value (pronounced "arbitrary" in some of the
103	  // hipper English-speaking countries), and can be changed to
104	  // suit particular needs.
105	  //
106	  // _GLIBCXX_RESOLVE_LIB_DEFECTS
107	  // 169. Bad efficiency of overflow() mandated
108	  // 432. stringbuf::overflow() makes only one write position
109	  //      available
110	  const __size_type __opt_len = std::max(__size_type(2 * __capacity),
111						 __size_type(512));
112	  const __size_type __len = std::min(__opt_len, __max_size);
113	  __string_type __tmp;
114	  __tmp.reserve(__len);
115	  if (this->pbase())
116	    __tmp.assign(this->pbase(), this->epptr() - this->pbase());
117	  __tmp.push_back(__conv);
118	  _M_string.swap(__tmp);
119	  _M_sync(const_cast<char_type*>(_M_string.data()),
120		  this->gptr() - this->eback(), this->pptr() - this->pbase());
121	}
122      else
123	*this->pptr() = __conv;
124      this->pbump(1);
125      return __c;
126    }
127
128  template <class _CharT, class _Traits, class _Alloc>
129    typename basic_stringbuf<_CharT, _Traits, _Alloc>::int_type
130    basic_stringbuf<_CharT, _Traits, _Alloc>::
131    underflow()
132    {
133      int_type __ret = traits_type::eof();
134      const bool __testin = this->_M_mode & ios_base::in;
135      if (__testin)
136	{
137	  // Update egptr() to match the actual string end.
138	  _M_update_egptr();
139
140	  if (this->gptr() < this->egptr())
141	    __ret = traits_type::to_int_type(*this->gptr());
142	}
143      return __ret;
144    }
145
146  template <class _CharT, class _Traits, class _Alloc>
147    typename basic_stringbuf<_CharT, _Traits, _Alloc>::pos_type
148    basic_stringbuf<_CharT, _Traits, _Alloc>::
149    seekoff(off_type __off, ios_base::seekdir __way, ios_base::openmode __mode)
150    {
151      pos_type __ret =  pos_type(off_type(-1));
152      bool __testin = (ios_base::in & this->_M_mode & __mode) != 0;
153      bool __testout = (ios_base::out & this->_M_mode & __mode) != 0;
154      const bool __testboth = __testin && __testout && __way != ios_base::cur;
155      __testin &= !(__mode & ios_base::out);
156      __testout &= !(__mode & ios_base::in);
157
158      // _GLIBCXX_RESOLVE_LIB_DEFECTS
159      // 453. basic_stringbuf::seekoff need not always fail for an empty stream.
160      const char_type* __beg = __testin ? this->eback() : this->pbase();
161      if ((__beg || !__off) && (__testin || __testout || __testboth))
162	{
163	  _M_update_egptr();
164
165	  off_type __newoffi = __off;
166	  off_type __newoffo = __newoffi;
167	  if (__way == ios_base::cur)
168	    {
169	      __newoffi += this->gptr() - __beg;
170	      __newoffo += this->pptr() - __beg;
171	    }
172	  else if (__way == ios_base::end)
173	    __newoffo = __newoffi += this->egptr() - __beg;
174
175	  if ((__testin || __testboth)
176	      && __newoffi >= 0
177	      && this->egptr() - __beg >= __newoffi)
178	    {
179	      this->gbump((__beg + __newoffi) - this->gptr());
180	      __ret = pos_type(__newoffi);
181	    }
182	  if ((__testout || __testboth)
183	      && __newoffo >= 0
184	      && this->egptr() - __beg >= __newoffo)
185	    {
186	      this->pbump((__beg + __newoffo) - this->pptr());
187	      __ret = pos_type(__newoffo);
188	    }
189	}
190      return __ret;
191    }
192
193  template <class _CharT, class _Traits, class _Alloc>
194    typename basic_stringbuf<_CharT, _Traits, _Alloc>::pos_type
195    basic_stringbuf<_CharT, _Traits, _Alloc>::
196    seekpos(pos_type __sp, ios_base::openmode __mode)
197    {
198      pos_type __ret =  pos_type(off_type(-1));
199      const bool __testin = (ios_base::in & this->_M_mode & __mode) != 0;
200      const bool __testout = (ios_base::out & this->_M_mode & __mode) != 0;
201
202      const char_type* __beg = __testin ? this->eback() : this->pbase();
203      if ((__beg || !off_type(__sp)) && (__testin || __testout))
204	{
205	  _M_update_egptr();
206
207	  const off_type __pos(__sp);
208	  const bool __testpos = (0 <= __pos
209				  && __pos <= this->egptr() - __beg);
210	  if (__testpos)
211	    {
212	      if (__testin)
213		this->gbump((__beg + __pos) - this->gptr());
214	      if (__testout)
215                this->pbump((__beg + __pos) - this->pptr());
216	      __ret = __sp;
217	    }
218	}
219      return __ret;
220    }
221
222  template <class _CharT, class _Traits, class _Alloc>
223    void
224    basic_stringbuf<_CharT, _Traits, _Alloc>::
225    _M_sync(char_type* __base, __size_type __i, __size_type __o)
226    {
227      const bool __testin = _M_mode & ios_base::in;
228      const bool __testout = _M_mode & ios_base::out;
229      char_type* __endg = __base + _M_string.size();
230      char_type* __endp = __base + _M_string.capacity();
231
232      if (__base != _M_string.data())
233	{
234	  // setbuf: __i == size of buffer area (_M_string.size() == 0).
235	  __endg += __i;
236	  __i = 0;
237	  __endp = __endg;
238	}
239
240      if (__testin)
241	this->setg(__base, __base + __i, __endg);
242      if (__testout)
243	{
244	  this->setp(__base, __endp);
245	  this->pbump(__o);
246	  // egptr() always tracks the string end.  When !__testin,
247	  // for the correct functioning of the streambuf inlines
248	  // the other get area pointers are identical.
249	  if (!__testin)
250	    this->setg(__endg, __endg, __endg);
251	}
252    }
253
254  // Inhibit implicit instantiations for required instantiations,
255  // which are defined via explicit instantiations elsewhere.
256  // NB:  This syntax is a GNU extension.
257#if _GLIBCXX_EXTERN_TEMPLATE
258  extern template class basic_stringbuf<char>;
259  extern template class basic_istringstream<char>;
260  extern template class basic_ostringstream<char>;
261  extern template class basic_stringstream<char>;
262
263#ifdef _GLIBCXX_USE_WCHAR_T
264  extern template class basic_stringbuf<wchar_t>;
265  extern template class basic_istringstream<wchar_t>;
266  extern template class basic_ostringstream<wchar_t>;
267  extern template class basic_stringstream<wchar_t>;
268#endif
269#endif
270
271_GLIBCXX_END_NAMESPACE
272
273#endif
274