1// String based streams -*- C++ -*-
2
3// Copyright (C) 1997-2021 Free Software Foundation, Inc.
4//
5// This file is part of the GNU ISO C++ Library. This library is free
6// software; you can redistribute it and/or modify it under the
7// terms of the GNU General Public License as published by the
8// Free Software Foundation; either version 3, or (at your option)
9// any later version.
10
11// This library is distributed in the hope that it will be useful,
12// but WITHOUT ANY WARRANTY; without even the implied warranty of
13// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14// GNU General Public License for more details.
15
16// Under Section 7 of GPL version 3, you are granted additional
17// permissions described in the GCC Runtime Library Exception, version
18// 3.1, as published by the Free Software Foundation.
19
20// You should have received a copy of the GNU General Public License and
21// a copy of the GCC Runtime Library Exception along with this program;
22// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23// <http://www.gnu.org/licenses/>.
24
25/** @file bits/sstream.tcc
26 * This is an internal header file, included by other library headers.
27 * Do not attempt to use it directly. @headername{sstream}
28 */
29
30//
31// ISO C++ 14882: 27.7 String-based streams
32//
33
34#ifndef _SSTREAM_TCC
35#define _SSTREAM_TCC 1
36
37#pragma GCC system_header
38
39namespace std _GLIBCXX_VISIBILITY(default)
40{
41_GLIBCXX_BEGIN_NAMESPACE_VERSION
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
92#if _GLIBCXX_USE_CXX11_ABI
93 if (size_t(this->epptr() - this->pbase()) < __capacity)
94 {
95 // There is additional capacity in _M_string that can be used.
96 char_type* __base = const_cast<char_type*>(_M_string.data());
97 _M_pbump(pbeg: __base, pend: __base + __capacity, off: this->pptr() - this->pbase());
98 if (_M_mode & ios_base::in)
99 {
100 const __size_type __nget = this->gptr() - this->eback();
101 const __size_type __eget = this->egptr() - this->eback();
102 this->setg(__base, __base + __nget, __base + __eget + 1);
103 }
104 *this->pptr() = traits_type::to_char_type(__c);
105 this->pbump(1);
106 return __c;
107 }
108#endif
109
110 const __size_type __max_size = _M_string.max_size();
111 const bool __testput = this->pptr() < this->epptr();
112 if (__builtin_expect(!__testput && __capacity == __max_size, false))
113 return traits_type::eof();
114
115 // Try to append __c into output sequence in one of two ways.
116 // Order these tests done in is unspecified by the standard.
117 const char_type __conv = traits_type::to_char_type(__c);
118 if (!__testput)
119 {
120 // NB: Start ostringstream buffers at 512 chars. This is an
121 // experimental value (pronounced "arbitrary" in some of the
122 // hipper English-speaking countries), and can be changed to
123 // suit particular needs.
124 //
125 // _GLIBCXX_RESOLVE_LIB_DEFECTS
126 // 169. Bad efficiency of overflow() mandated
127 // 432. stringbuf::overflow() makes only one write position
128 // available
129 const __size_type __opt_len = std::max(__size_type(2 * __capacity),
130 __size_type(512));
131 const __size_type __len = std::min(__opt_len, __max_size);
132 __string_type __tmp(_M_string.get_allocator());
133 __tmp.reserve(__len);
134 if (this->pbase())
135 __tmp.assign(this->pbase(), this->epptr() - this->pbase());
136 __tmp.push_back(__conv);
137 _M_string.swap(__tmp);
138 _M_sync(base: const_cast<char_type*>(_M_string.data()),
139 i: this->gptr() - this->eback(), o: this->pptr() - this->pbase());
140 }
141 else
142 *this->pptr() = __conv;
143 this->pbump(1);
144 return __c;
145 }
146
147 template <class _CharT, class _Traits, class _Alloc>
148 typename basic_stringbuf<_CharT, _Traits, _Alloc>::int_type
149 basic_stringbuf<_CharT, _Traits, _Alloc>::
150 underflow()
151 {
152 int_type __ret = traits_type::eof();
153 const bool __testin = this->_M_mode & ios_base::in;
154 if (__testin)
155 {
156 // Update egptr() to match the actual string end.
157 _M_update_egptr();
158
159 if (this->gptr() < this->egptr())
160 __ret = traits_type::to_int_type(*this->gptr());
161 }
162 return __ret;
163 }
164
165 template <class _CharT, class _Traits, class _Alloc>
166 typename basic_stringbuf<_CharT, _Traits, _Alloc>::pos_type
167 basic_stringbuf<_CharT, _Traits, _Alloc>::
168 seekoff(off_type __off, ios_base::seekdir __way, ios_base::openmode __mode)
169 {
170 pos_type __ret = pos_type(off_type(-1));
171 bool __testin = (ios_base::in & this->_M_mode & __mode) != 0;
172 bool __testout = (ios_base::out & this->_M_mode & __mode) != 0;
173 const bool __testboth = __testin && __testout && __way != ios_base::cur;
174 __testin &= !(__mode & ios_base::out);
175 __testout &= !(__mode & ios_base::in);
176
177 // _GLIBCXX_RESOLVE_LIB_DEFECTS
178 // 453. basic_stringbuf::seekoff need not always fail for an empty stream.
179 const char_type* __beg = __testin ? this->eback() : this->pbase();
180 if ((__beg || !__off) && (__testin || __testout || __testboth))
181 {
182 _M_update_egptr();
183
184 off_type __newoffi = __off;
185 off_type __newoffo = __newoffi;
186 if (__way == ios_base::cur)
187 {
188 __newoffi += this->gptr() - __beg;
189 __newoffo += this->pptr() - __beg;
190 }
191 else if (__way == ios_base::end)
192 __newoffo = __newoffi += this->egptr() - __beg;
193
194 if ((__testin || __testboth)
195 && __newoffi >= 0
196 && this->egptr() - __beg >= __newoffi)
197 {
198 this->setg(this->eback(), this->eback() + __newoffi,
199 this->egptr());
200 __ret = pos_type(__newoffi);
201 }
202 if ((__testout || __testboth)
203 && __newoffo >= 0
204 && this->egptr() - __beg >= __newoffo)
205 {
206 _M_pbump(pbeg: this->pbase(), pend: this->epptr(), off: __newoffo);
207 __ret = pos_type(__newoffo);
208 }
209 }
210 return __ret;
211 }
212
213 template <class _CharT, class _Traits, class _Alloc>
214 typename basic_stringbuf<_CharT, _Traits, _Alloc>::pos_type
215 basic_stringbuf<_CharT, _Traits, _Alloc>::
216 seekpos(pos_type __sp, ios_base::openmode __mode)
217 {
218 pos_type __ret = pos_type(off_type(-1));
219 const bool __testin = (ios_base::in & this->_M_mode & __mode) != 0;
220 const bool __testout = (ios_base::out & this->_M_mode & __mode) != 0;
221
222 const char_type* __beg = __testin ? this->eback() : this->pbase();
223 if ((__beg || !off_type(__sp)) && (__testin || __testout))
224 {
225 _M_update_egptr();
226
227 const off_type __pos(__sp);
228 const bool __testpos = (0 <= __pos
229 && __pos <= this->egptr() - __beg);
230 if (__testpos)
231 {
232 if (__testin)
233 this->setg(this->eback(), this->eback() + __pos,
234 this->egptr());
235 if (__testout)
236 _M_pbump(pbeg: this->pbase(), pend: this->epptr(), off: __pos);
237 __ret = __sp;
238 }
239 }
240 return __ret;
241 }
242
243 template <class _CharT, class _Traits, class _Alloc>
244 void
245 basic_stringbuf<_CharT, _Traits, _Alloc>::
246 _M_sync(char_type* __base, __size_type __i, __size_type __o)
247 {
248 const bool __testin = _M_mode & ios_base::in;
249 const bool __testout = _M_mode & ios_base::out;
250 char_type* __endg = __base + _M_string.size();
251 char_type* __endp = __base + _M_string.capacity();
252
253 if (__base != _M_string.data())
254 {
255 // setbuf: __i == size of buffer area (_M_string.size() == 0).
256 __endg += __i;
257 __i = 0;
258 __endp = __endg;
259 }
260
261 if (__testin)
262 this->setg(__base, __base + __i, __endg);
263 if (__testout)
264 {
265 _M_pbump(pbeg: __base, pend: __endp, off: __o);
266 // egptr() always tracks the string end. When !__testin,
267 // for the correct functioning of the streambuf inlines
268 // the other get area pointers are identical.
269 if (!__testin)
270 this->setg(__endg, __endg, __endg);
271 }
272 }
273
274 template <class _CharT, class _Traits, class _Alloc>
275 void
276 basic_stringbuf<_CharT, _Traits, _Alloc>::
277 _M_pbump(char_type* __pbeg, char_type* __pend, off_type __off)
278 {
279 this->setp(__pbeg, __pend);
280 while (__off > __gnu_cxx::__numeric_traits<int>::__max)
281 {
282 this->pbump(__gnu_cxx::__numeric_traits<int>::__max);
283 __off -= __gnu_cxx::__numeric_traits<int>::__max;
284 }
285 this->pbump(__off);
286 }
287
288 // Inhibit implicit instantiations for required instantiations,
289 // which are defined via explicit instantiations elsewhere.
290#if _GLIBCXX_EXTERN_TEMPLATE
291 extern template class basic_stringbuf<char>;
292 extern template class basic_istringstream<char>;
293 extern template class basic_ostringstream<char>;
294 extern template class basic_stringstream<char>;
295
296#ifdef _GLIBCXX_USE_WCHAR_T
297 extern template class basic_stringbuf<wchar_t>;
298 extern template class basic_istringstream<wchar_t>;
299 extern template class basic_ostringstream<wchar_t>;
300 extern template class basic_stringstream<wchar_t>;
301#endif
302#endif
303
304_GLIBCXX_END_NAMESPACE_VERSION
305} // namespace std
306
307#endif
308

source code of include/c++/11/bits/sstream.tcc