1 // String based streams -*- C++ -*- 2 3 // Copyright (C) 1997-2022 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>:: pbackfail(int_type __c)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>:: overflow(int_type __c)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(__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>:: underflow()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>:: seekoff(off_type __off,ios_base::seekdir __way,ios_base::openmode __mode)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>:: seekpos(pos_type __sp,ios_base::openmode __mode)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>:: _M_sync(char_type * __base,__size_type __i,__size_type __o)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>:: _M_pbump(char_type * __pbeg,char_type * __pend,off_type __off)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