1// String based streams -*- C++ -*-
2
3// Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006
4// Free Software Foundation, Inc.
5//
6// This file is part of the GNU ISO C++ Library.  This library is free
7// software; you can redistribute it and/or modify it under the
8// terms of the GNU General Public License as published by the
9// Free Software Foundation; either version 2, or (at your option)
10// any later version.
11
12// This library is distributed in the hope that it will be useful,
13// but WITHOUT ANY WARRANTY; without even the implied warranty of
14// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15// GNU General Public License for more details.
16
17// You should have received a copy of the GNU General Public License along
18// with this library; see the file COPYING.  If not, write to the Free
19// Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
20// USA.
21
22// As a special exception, you may use this file as part of a free software
23// library without restriction.  Specifically, if other files instantiate
24// templates or use macros or inline functions from this file, or you compile
25// this file and link it with other files to produce an executable, this
26// file does not by itself cause the resulting executable to be covered by
27// the GNU General Public License.  This exception does not however
28// invalidate any other reasons why the executable file might be covered by
29// the GNU General Public License.
30
31/** @file sstream.tcc
32 *  This is an internal header file, included by other library headers.
33 *  You should not attempt to use it directly.
34 */
35
36//
37// ISO C++ 14882: 27.7  String-based streams
38//
39
40#ifndef _SSTREAM_TCC
41#define _SSTREAM_TCC 1
42
43#pragma GCC system_header
44
45#include <sstream>
46
47namespace std
48{
49  template <class _CharT, class _Traits, class _Alloc>
50    typename basic_stringbuf<_CharT, _Traits, _Alloc>::int_type
51    basic_stringbuf<_CharT, _Traits, _Alloc>::
52    pbackfail(int_type __c)
53    {
54      int_type __ret = traits_type::eof();
55      if (this->eback() < this->gptr())
56	{
57	  // Try to put back __c into input sequence in one of three ways.
58	  // Order these tests done in is unspecified by the standard.
59	  const bool __testeof = traits_type::eq_int_type(__c, __ret);
60	  if (!__testeof)
61	    {
62	      const bool __testeq = traits_type::eq(traits_type::
63						    to_char_type(__c),
64						    this->gptr()[-1]);	  
65	      const bool __testout = this->_M_mode & ios_base::out;
66	      if (__testeq || __testout)
67		{
68		  this->gbump(-1);
69		  if (!__testeq)
70		    *this->gptr() = traits_type::to_char_type(__c);
71		  __ret = __c;
72		}
73	    }
74	  else
75	    {
76	      this->gbump(-1);
77	      __ret = traits_type::not_eof(__c);
78	    }
79	}
80      return __ret;
81    }
82
83  template <class _CharT, class _Traits, class _Alloc>
84    typename basic_stringbuf<_CharT, _Traits, _Alloc>::int_type
85    basic_stringbuf<_CharT, _Traits, _Alloc>::
86    overflow(int_type __c)
87    {
88      const bool __testout = this->_M_mode & ios_base::out;
89      if (__builtin_expect(!__testout, false))
90	return traits_type::eof();
91
92      const bool __testeof = traits_type::eq_int_type(__c, traits_type::eof());
93      if (__builtin_expect(__testeof, false))
94	return traits_type::not_eof(__c);
95
96      const __size_type __capacity = _M_string.capacity();
97      const __size_type __max_size = _M_string.max_size();
98      const bool __testput = this->pptr() < this->epptr();
99      if (__builtin_expect(!__testput && __capacity == __max_size, false))
100	return traits_type::eof();
101
102      // Try to append __c into output sequence in one of two ways.
103      // Order these tests done in is unspecified by the standard.
104      if (!__testput)
105	{
106	  // NB: Start ostringstream buffers at 512 chars. This is an
107	  // experimental value (pronounced "arbitrary" in some of the
108	  // hipper english-speaking countries), and can be changed to
109	  // suit particular needs.
110	  // Then, in virtue of DR 169 (TC) we are allowed to grow more
111	  // than one char.
112	  const __size_type __opt_len = std::max(__size_type(2 * __capacity),
113						 __size_type(512));
114	  const __size_type __len = std::min(__opt_len, __max_size);
115	  __string_type __tmp;
116	  __tmp.reserve(__len);
117	  if (this->pbase())
118	    __tmp.assign(this->pbase(), this->epptr() - this->pbase());
119	  _M_string.swap(__tmp);
120	  _M_sync(const_cast<char_type*>(_M_string.data()),
121		  this->gptr() - this->eback(), this->pptr() - this->pbase());
122	}
123      return this->sputc(traits_type::to_char_type(__c));
124    }
125
126  template <class _CharT, class _Traits, class _Alloc>
127    typename basic_stringbuf<_CharT, _Traits, _Alloc>::int_type
128    basic_stringbuf<_CharT, _Traits, _Alloc>::
129    underflow()
130    {
131      int_type __ret = traits_type::eof();
132      const bool __testin = this->_M_mode & ios_base::in;
133      if (__testin)
134	{
135	  // Update egptr() to match the actual string end.
136	  _M_update_egptr();
137
138	  if (this->gptr() < this->egptr())
139	    __ret = traits_type::to_int_type(*this->gptr());
140	}
141      return __ret;
142    }
143
144  template <class _CharT, class _Traits, class _Alloc>
145    typename basic_stringbuf<_CharT, _Traits, _Alloc>::pos_type
146    basic_stringbuf<_CharT, _Traits, _Alloc>::
147    seekoff(off_type __off, ios_base::seekdir __way, ios_base::openmode __mode)
148    {
149      pos_type __ret =  pos_type(off_type(-1));
150      bool __testin = (ios_base::in & this->_M_mode & __mode) != 0;
151      bool __testout = (ios_base::out & this->_M_mode & __mode) != 0;
152      const bool __testboth = __testin && __testout && __way != ios_base::cur;
153      __testin &= !(__mode & ios_base::out);
154      __testout &= !(__mode & ios_base::in);
155
156      // _GLIBCXX_RESOLVE_LIB_DEFECTS
157      // 453. basic_stringbuf::seekoff need not always fail for an empty stream.
158      const char_type* __beg = __testin ? this->eback() : this->pbase();
159      if ((__beg || !__off) && (__testin || __testout || __testboth))
160	{
161	  _M_update_egptr();
162
163	  off_type __newoffi = __off;
164	  off_type __newoffo = __newoffi;
165	  if (__way == ios_base::cur)
166	    {
167	      __newoffi += this->gptr() - __beg;
168	      __newoffo += this->pptr() - __beg;
169	    }
170	  else if (__way == ios_base::end)
171	    __newoffo = __newoffi += this->egptr() - __beg;
172
173	  if ((__testin || __testboth)
174	      && __newoffi >= 0
175	      && this->egptr() - __beg >= __newoffi)
176	    {
177	      this->gbump((__beg + __newoffi) - this->gptr());
178	      __ret = pos_type(__newoffi);
179	    }
180	  if ((__testout || __testboth)
181	      && __newoffo >= 0
182	      && this->egptr() - __beg >= __newoffo)
183	    {
184	      this->pbump((__beg + __newoffo) - this->pptr());
185	      __ret = pos_type(__newoffo);
186	    }
187	}
188      return __ret;
189    }
190
191  template <class _CharT, class _Traits, class _Alloc>
192    typename basic_stringbuf<_CharT, _Traits, _Alloc>::pos_type
193    basic_stringbuf<_CharT, _Traits, _Alloc>::
194    seekpos(pos_type __sp, ios_base::openmode __mode)
195    {
196      pos_type __ret =  pos_type(off_type(-1));
197      const bool __testin = (ios_base::in & this->_M_mode & __mode) != 0;
198      const bool __testout = (ios_base::out & this->_M_mode & __mode) != 0;
199
200      const char_type* __beg = __testin ? this->eback() : this->pbase();
201      if ((__beg || !off_type(__sp)) && (__testin || __testout))
202	{
203	  _M_update_egptr();
204
205	  const off_type __pos(__sp);
206	  const bool __testpos = 0 <= __pos
207	                         && __pos <=  this->egptr() - __beg;
208	  if (__testpos)
209	    {
210	      if (__testin)
211		this->gbump((__beg + __pos) - this->gptr());
212	      if (__testout)
213                this->pbump((__beg + __pos) - this->pptr());
214	      __ret = __sp;
215	    }
216	}
217      return __ret;
218    }
219
220  template <class _CharT, class _Traits, class _Alloc>
221    void
222    basic_stringbuf<_CharT, _Traits, _Alloc>::
223    _M_sync(char_type* __base, __size_type __i, __size_type __o)
224    {
225      const bool __testin = _M_mode & ios_base::in;
226      const bool __testout = _M_mode & ios_base::out;
227      char_type* __endg = __base + _M_string.size();
228      char_type* __endp = __base + _M_string.capacity();
229
230      if (__base != _M_string.data())
231	{
232	  // setbuf: __i == size of buffer area (_M_string.size() == 0).
233	  __endg += __i;
234	  __i = 0;
235	  __endp = __endg;
236	}
237
238      if (__testin)
239	this->setg(__base, __base + __i, __endg);
240      if (__testout)
241	{
242	  this->setp(__base, __endp);
243	  this->pbump(__o);
244	  // egptr() always tracks the string end.  When !__testin,
245	  // for the correct functioning of the streambuf inlines
246	  // the other get area pointers are identical.
247	  if (!__testin)
248	    this->setg(__endg, __endg, __endg);
249	}
250    }
251
252  // Inhibit implicit instantiations for required instantiations,
253  // which are defined via explicit instantiations elsewhere.
254  // NB:  This syntax is a GNU extension.
255#if _GLIBCXX_EXTERN_TEMPLATE
256  extern template class basic_stringbuf<char>;
257  extern template class basic_istringstream<char>;
258  extern template class basic_ostringstream<char>;
259  extern template class basic_stringstream<char>;
260
261#ifdef _GLIBCXX_USE_WCHAR_T
262  extern template class basic_stringbuf<wchar_t>;
263  extern template class basic_istringstream<wchar_t>;
264  extern template class basic_ostringstream<wchar_t>;
265  extern template class basic_stringstream<wchar_t>;
266#endif
267#endif
268} // namespace std
269
270#endif
271