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 289
