1// String based streams -*- C++ -*- 
2 
3// Copyright (C) 1997-2019 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 ((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(__base, __base + __capacity, 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(const_cast<char_type*>(_M_string.data()), 
139 this->gptr() - this->eback(), 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(this->pbase(), this->epptr(), __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(this->pbase(), this->epptr(), __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(__base, __endp, __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