1 // String based streams -*- C++ -*- 2 3 // Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 4 // 2006, 2007, 2009 5 // Free Software Foundation, Inc. 6 // 7 // This file is part of the GNU ISO C++ Library. This library is free 8 // software; you can redistribute it and/or modify it under the 9 // terms of the GNU General Public License as published by the 10 // Free Software Foundation; either version 3, or (at your option) 11 // any later version. 12 13 // This library is distributed in the hope that it will be useful, 14 // but WITHOUT ANY WARRANTY; without even the implied warranty of 15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 // GNU General Public License for more details. 17 18 // Under Section 7 of GPL version 3, you are granted additional 19 // permissions described in the GCC Runtime Library Exception, version 20 // 3.1, as published by the Free Software Foundation. 21 22 // You should have received a copy of the GNU General Public License and 23 // a copy of the GCC Runtime Library Exception along with this program; 24 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 25 // <http://www.gnu.org/licenses/>. 26 27 /** @file sstream.tcc 28 * This is an internal header file, included by other library headers. 29 * You should not attempt to use it directly. 30 */ 31 32 // 33 // ISO C++ 14882: 27.7 String-based streams 34 // 35 36 #ifndef _SSTREAM_TCC 37 #define _SSTREAM_TCC 1 38 39 #pragma GCC system_header 40 41 _GLIBCXX_BEGIN_NAMESPACE(std) 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->gbump((__beg + __newoffi) - this->gptr()); 180 __ret = pos_type(__newoffi); 181 } 182 if ((__testout || __testboth) 183 && __newoffo >= 0 184 && this->egptr() - __beg >= __newoffo) 185 { 186 this->pbump((__beg + __newoffo) - this->pptr()); 187 __ret = pos_type(__newoffo); 188 } 189 } 190 return __ret; 191 } 192 193 template <class _CharT, class _Traits, class _Alloc> 194 typename basic_stringbuf<_CharT, _Traits, _Alloc>::pos_type 195 basic_stringbuf<_CharT, _Traits, _Alloc>:: 196 seekpos(pos_type __sp, ios_base::openmode __mode) 197 { 198 pos_type __ret = pos_type(off_type(-1)); 199 const bool __testin = (ios_base::in & this->_M_mode & __mode) != 0; 200 const bool __testout = (ios_base::out & this->_M_mode & __mode) != 0; 201 202 const char_type* __beg = __testin ? this->eback() : this->pbase(); 203 if ((__beg || !off_type(__sp)) && (__testin || __testout)) 204 { 205 _M_update_egptr(); 206 207 const off_type __pos(__sp); 208 const bool __testpos = (0 <= __pos 209 && __pos <= this->egptr() - __beg); 210 if (__testpos) 211 { 212 if (__testin) 213 this->gbump((__beg + __pos) - this->gptr()); 214 if (__testout) 215 this->pbump((__beg + __pos) - this->pptr()); 216 __ret = __sp; 217 } 218 } 219 return __ret; 220 } 221 222 template <class _CharT, class _Traits, class _Alloc> 223 void 224 basic_stringbuf<_CharT, _Traits, _Alloc>:: 225 _M_sync(char_type* __base, __size_type __i, __size_type __o) 226 { 227 const bool __testin = _M_mode & ios_base::in; 228 const bool __testout = _M_mode & ios_base::out; 229 char_type* __endg = __base + _M_string.size(); 230 char_type* __endp = __base + _M_string.capacity(); 231 232 if (__base != _M_string.data()) 233 { 234 // setbuf: __i == size of buffer area (_M_string.size() == 0). 235 __endg += __i; 236 __i = 0; 237 __endp = __endg; 238 } 239 240 if (__testin) 241 this->setg(__base, __base + __i, __endg); 242 if (__testout) 243 { 244 this->setp(__base, __endp); 245 this->pbump(__o); 246 // egptr() always tracks the string end. When !__testin, 247 // for the correct functioning of the streambuf inlines 248 // the other get area pointers are identical. 249 if (!__testin) 250 this->setg(__endg, __endg, __endg); 251 } 252 } 253 254 // Inhibit implicit instantiations for required instantiations, 255 // which are defined via explicit instantiations elsewhere. 256 // NB: This syntax is a GNU extension. 257 #if _GLIBCXX_EXTERN_TEMPLATE 258 extern template class basic_stringbuf<char>; 259 extern template class basic_istringstream<char>; 260 extern template class basic_ostringstream<char>; 261 extern template class basic_stringstream<char>; 262 263 #ifdef _GLIBCXX_USE_WCHAR_T 264 extern template class basic_stringbuf<wchar_t>; 265 extern template class basic_istringstream<wchar_t>; 266 extern template class basic_ostringstream<wchar_t>; 267 extern template class basic_stringstream<wchar_t>; 268 #endif 269 #endif 270 271 _GLIBCXX_END_NAMESPACE 272 273 #endif 274