libstdc++

sstream.tcc
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1 // String based streams -*- C++ -*-
2
3 // Copyright (C) 1997-2013 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
39 namespace 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 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->setg(this->eback(), this->eback() + __newoffi,
180 this->egptr());
181 __ret = pos_type(__newoffi);
182 }
183 if ((__testout || __testboth)
184 && __newoffo >= 0
185 && this->egptr() - __beg >= __newoffo)
186 {
187 _M_pbump(this->pbase(), this->epptr(), __newoffo);
188 __ret = pos_type(__newoffo);
189 }
190 }
191 return __ret;
192 }
193
194 template <class _CharT, class _Traits, class _Alloc>
195 typename basic_stringbuf<_CharT, _Traits, _Alloc>::pos_type
196 basic_stringbuf<_CharT, _Traits, _Alloc>::
197 seekpos(pos_type __sp, ios_base::openmode __mode)
198 {
199 pos_type __ret = pos_type(off_type(-1));
200 const bool __testin = (ios_base::in & this->_M_mode & __mode) != 0;
201 const bool __testout = (ios_base::out & this->_M_mode & __mode) != 0;
202
203 const char_type* __beg = __testin ? this->eback() : this->pbase();
204 if ((__beg || !off_type(__sp)) && (__testin || __testout))
205 {
206 _M_update_egptr();
207
208 const off_type __pos(__sp);
209 const bool __testpos = (0 <= __pos
210 && __pos <= this->egptr() - __beg);
211 if (__testpos)
212 {
213 if (__testin)
214 this->setg(this->eback(), this->eback() + __pos,
215 this->egptr());
216 if (__testout)
217 _M_pbump(this->pbase(), this->epptr(), __pos);
218 __ret = __sp;
219 }
220 }
221 return __ret;
222 }
223
224 template <class _CharT, class _Traits, class _Alloc>
225 void
226 basic_stringbuf<_CharT, _Traits, _Alloc>::
227 _M_sync(char_type* __base, __size_type __i, __size_type __o)
228 {
229 const bool __testin = _M_mode & ios_base::in;
230 const bool __testout = _M_mode & ios_base::out;
231 char_type* __endg = __base + _M_string.size();
232 char_type* __endp = __base + _M_string.capacity();
233
234 if (__base != _M_string.data())
235 {
236 // setbuf: __i == size of buffer area (_M_string.size() == 0).
237 __endg += __i;
238 __i = 0;
239 __endp = __endg;
240 }
241
242 if (__testin)
243 this->setg(__base, __base + __i, __endg);
244 if (__testout)
245 {
246 _M_pbump(__base, __endp, __o);
247 // egptr() always tracks the string end. When !__testin,
248 // for the correct functioning of the streambuf inlines
249 // the other get area pointers are identical.
250 if (!__testin)
251 this->setg(__endg, __endg, __endg);
252 }
253 }
254
255 template <class _CharT, class _Traits, class _Alloc>
256 void
257 basic_stringbuf<_CharT, _Traits, _Alloc>::
258 _M_pbump(char_type* __pbeg, char_type* __pend, off_type __off)
259 {
260 this->setp(__pbeg, __pend);
261 while (__off > __gnu_cxx::__numeric_traits<int>::__max)
262 {
263 this->pbump(__gnu_cxx::__numeric_traits<int>::__max);
264 __off -= __gnu_cxx::__numeric_traits<int>::__max;
265 }
266 this->pbump(__off);
267 }
268
269 // Inhibit implicit instantiations for required instantiations,
270 // which are defined via explicit instantiations elsewhere.
271 #if _GLIBCXX_EXTERN_TEMPLATE
272 extern template class basic_stringbuf<char>;
273 extern template class basic_istringstream<char>;
274 extern template class basic_ostringstream<char>;
275 extern template class basic_stringstream<char>;
276
277 #ifdef _GLIBCXX_USE_WCHAR_T
278 extern template class basic_stringbuf<wchar_t>;
279 extern template class basic_istringstream<wchar_t>;
280 extern template class basic_ostringstream<wchar_t>;
281 extern template class basic_stringstream<wchar_t>;
282 #endif
283 #endif
284
285 _GLIBCXX_END_NAMESPACE_VERSION
286 } // namespace std
287
288 #endif