libstdc++
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00001 // String based streams -*- C++ -*- 00002 00003 // Copyright (C) 1997-2019 Free Software Foundation, Inc. 00004 // 00005 // This file is part of the GNU ISO C++ Library. This library is free 00006 // software; you can redistribute it and/or modify it under the 00007 // terms of the GNU General Public License as published by the 00008 // Free Software Foundation; either version 3, or (at your option) 00009 // any later version. 00010 00011 // This library is distributed in the hope that it will be useful, 00012 // but WITHOUT ANY WARRANTY; without even the implied warranty of 00013 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00014 // GNU General Public License for more details. 00015 00016 // Under Section 7 of GPL version 3, you are granted additional 00017 // permissions described in the GCC Runtime Library Exception, version 00018 // 3.1, as published by the Free Software Foundation. 00019 00020 // You should have received a copy of the GNU General Public License and 00021 // a copy of the GCC Runtime Library Exception along with this program; 00022 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 00023 // <http://www.gnu.org/licenses/>. 00024 00025 /** @file bits/sstream.tcc 00026 * This is an internal header file, included by other library headers. 00027 * Do not attempt to use it directly. @headername{sstream} 00028 */ 00029 00030 // 00031 // ISO C++ 14882: 27.7 String-based streams 00032 // 00033 00034 #ifndef _SSTREAM_TCC 00035 #define _SSTREAM_TCC 1 00036 00037 #pragma GCC system_header 00038 00039 namespace std _GLIBCXX_VISIBILITY(default) 00040 { 00041 _GLIBCXX_BEGIN_NAMESPACE_VERSION 00042 00043 template <class _CharT, class _Traits, class _Alloc> 00044 typename basic_stringbuf<_CharT, _Traits, _Alloc>::int_type 00045 basic_stringbuf<_CharT, _Traits, _Alloc>:: 00046 pbackfail(int_type __c) 00047 { 00048 int_type __ret = traits_type::eof(); 00049 if (this->eback() < this->gptr()) 00050 { 00051 // Try to put back __c into input sequence in one of three ways. 00052 // Order these tests done in is unspecified by the standard. 00053 const bool __testeof = traits_type::eq_int_type(__c, __ret); 00054 if (!__testeof) 00055 { 00056 const bool __testeq = traits_type::eq(traits_type:: 00057 to_char_type(__c), 00058 this->gptr()[-1]); 00059 const bool __testout = this->_M_mode & ios_base::out; 00060 if (__testeq || __testout) 00061 { 00062 this->gbump(-1); 00063 if (!__testeq) 00064 *this->gptr() = traits_type::to_char_type(__c); 00065 __ret = __c; 00066 } 00067 } 00068 else 00069 { 00070 this->gbump(-1); 00071 __ret = traits_type::not_eof(__c); 00072 } 00073 } 00074 return __ret; 00075 } 00076 00077 template <class _CharT, class _Traits, class _Alloc> 00078 typename basic_stringbuf<_CharT, _Traits, _Alloc>::int_type 00079 basic_stringbuf<_CharT, _Traits, _Alloc>:: 00080 overflow(int_type __c) 00081 { 00082 const bool __testout = this->_M_mode & ios_base::out; 00083 if (__builtin_expect(!__testout, false)) 00084 return traits_type::eof(); 00085 00086 const bool __testeof = traits_type::eq_int_type(__c, traits_type::eof()); 00087 if (__builtin_expect(__testeof, false)) 00088 return traits_type::not_eof(__c); 00089 00090 const __size_type __capacity = _M_string.capacity(); 00091 00092 #if _GLIBCXX_USE_CXX11_ABI 00093 if ((this->epptr() - this->pbase()) < __capacity) 00094 { 00095 // There is additional capacity in _M_string that can be used. 00096 char_type* __base = const_cast<char_type*>(_M_string.data()); 00097 _M_pbump(__base, __base + __capacity, this->pptr() - this->pbase()); 00098 if (_M_mode & ios_base::in) 00099 { 00100 const __size_type __nget = this->gptr() - this->eback(); 00101 const __size_type __eget = this->egptr() - this->eback(); 00102 this->setg(__base, __base + __nget, __base + __eget + 1); 00103 } 00104 *this->pptr() = traits_type::to_char_type(__c); 00105 this->pbump(1); 00106 return __c; 00107 } 00108 #endif 00109 00110 const __size_type __max_size = _M_string.max_size(); 00111 const bool __testput = this->pptr() < this->epptr(); 00112 if (__builtin_expect(!__testput && __capacity == __max_size, false)) 00113 return traits_type::eof(); 00114 00115 // Try to append __c into output sequence in one of two ways. 00116 // Order these tests done in is unspecified by the standard. 00117 const char_type __conv = traits_type::to_char_type(__c); 00118 if (!__testput) 00119 { 00120 // NB: Start ostringstream buffers at 512 chars. This is an 00121 // experimental value (pronounced "arbitrary" in some of the 00122 // hipper English-speaking countries), and can be changed to 00123 // suit particular needs. 00124 // 00125 // _GLIBCXX_RESOLVE_LIB_DEFECTS 00126 // 169. Bad efficiency of overflow() mandated 00127 // 432. stringbuf::overflow() makes only one write position 00128 // available 00129 const __size_type __opt_len = std::max(__size_type(2 * __capacity), 00130 __size_type(512)); 00131 const __size_type __len = std::min(__opt_len, __max_size); 00132 __string_type __tmp(_M_string.get_allocator()); 00133 __tmp.reserve(__len); 00134 if (this->pbase()) 00135 __tmp.assign(this->pbase(), this->epptr() - this->pbase()); 00136 __tmp.push_back(__conv); 00137 _M_string.swap(__tmp); 00138 _M_sync(const_cast<char_type*>(_M_string.data()), 00139 this->gptr() - this->eback(), this->pptr() - this->pbase()); 00140 } 00141 else 00142 *this->pptr() = __conv; 00143 this->pbump(1); 00144 return __c; 00145 } 00146 00147 template <class _CharT, class _Traits, class _Alloc> 00148 typename basic_stringbuf<_CharT, _Traits, _Alloc>::int_type 00149 basic_stringbuf<_CharT, _Traits, _Alloc>:: 00150 underflow() 00151 { 00152 int_type __ret = traits_type::eof(); 00153 const bool __testin = this->_M_mode & ios_base::in; 00154 if (__testin) 00155 { 00156 // Update egptr() to match the actual string end. 00157 _M_update_egptr(); 00158 00159 if (this->gptr() < this->egptr()) 00160 __ret = traits_type::to_int_type(*this->gptr()); 00161 } 00162 return __ret; 00163 } 00164 00165 template <class _CharT, class _Traits, class _Alloc> 00166 typename basic_stringbuf<_CharT, _Traits, _Alloc>::pos_type 00167 basic_stringbuf<_CharT, _Traits, _Alloc>:: 00168 seekoff(off_type __off, ios_base::seekdir __way, ios_base::openmode __mode) 00169 { 00170 pos_type __ret = pos_type(off_type(-1)); 00171 bool __testin = (ios_base::in & this->_M_mode & __mode) != 0; 00172 bool __testout = (ios_base::out & this->_M_mode & __mode) != 0; 00173 const bool __testboth = __testin && __testout && __way != ios_base::cur; 00174 __testin &= !(__mode & ios_base::out); 00175 __testout &= !(__mode & ios_base::in); 00176 00177 // _GLIBCXX_RESOLVE_LIB_DEFECTS 00178 // 453. basic_stringbuf::seekoff need not always fail for an empty stream. 00179 const char_type* __beg = __testin ? this->eback() : this->pbase(); 00180 if ((__beg || !__off) && (__testin || __testout || __testboth)) 00181 { 00182 _M_update_egptr(); 00183 00184 off_type __newoffi = __off; 00185 off_type __newoffo = __newoffi; 00186 if (__way == ios_base::cur) 00187 { 00188 __newoffi += this->gptr() - __beg; 00189 __newoffo += this->pptr() - __beg; 00190 } 00191 else if (__way == ios_base::end) 00192 __newoffo = __newoffi += this->egptr() - __beg; 00193 00194 if ((__testin || __testboth) 00195 && __newoffi >= 0 00196 && this->egptr() - __beg >= __newoffi) 00197 { 00198 this->setg(this->eback(), this->eback() + __newoffi, 00199 this->egptr()); 00200 __ret = pos_type(__newoffi); 00201 } 00202 if ((__testout || __testboth) 00203 && __newoffo >= 0 00204 && this->egptr() - __beg >= __newoffo) 00205 { 00206 _M_pbump(this->pbase(), this->epptr(), __newoffo); 00207 __ret = pos_type(__newoffo); 00208 } 00209 } 00210 return __ret; 00211 } 00212 00213 template <class _CharT, class _Traits, class _Alloc> 00214 typename basic_stringbuf<_CharT, _Traits, _Alloc>::pos_type 00215 basic_stringbuf<_CharT, _Traits, _Alloc>:: 00216 seekpos(pos_type __sp, ios_base::openmode __mode) 00217 { 00218 pos_type __ret = pos_type(off_type(-1)); 00219 const bool __testin = (ios_base::in & this->_M_mode & __mode) != 0; 00220 const bool __testout = (ios_base::out & this->_M_mode & __mode) != 0; 00221 00222 const char_type* __beg = __testin ? this->eback() : this->pbase(); 00223 if ((__beg || !off_type(__sp)) && (__testin || __testout)) 00224 { 00225 _M_update_egptr(); 00226 00227 const off_type __pos(__sp); 00228 const bool __testpos = (0 <= __pos 00229 && __pos <= this->egptr() - __beg); 00230 if (__testpos) 00231 { 00232 if (__testin) 00233 this->setg(this->eback(), this->eback() + __pos, 00234 this->egptr()); 00235 if (__testout) 00236 _M_pbump(this->pbase(), this->epptr(), __pos); 00237 __ret = __sp; 00238 } 00239 } 00240 return __ret; 00241 } 00242 00243 template <class _CharT, class _Traits, class _Alloc> 00244 void 00245 basic_stringbuf<_CharT, _Traits, _Alloc>:: 00246 _M_sync(char_type* __base, __size_type __i, __size_type __o) 00247 { 00248 const bool __testin = _M_mode & ios_base::in; 00249 const bool __testout = _M_mode & ios_base::out; 00250 char_type* __endg = __base + _M_string.size(); 00251 char_type* __endp = __base + _M_string.capacity(); 00252 00253 if (__base != _M_string.data()) 00254 { 00255 // setbuf: __i == size of buffer area (_M_string.size() == 0). 00256 __endg += __i; 00257 __i = 0; 00258 __endp = __endg; 00259 } 00260 00261 if (__testin) 00262 this->setg(__base, __base + __i, __endg); 00263 if (__testout) 00264 { 00265 _M_pbump(__base, __endp, __o); 00266 // egptr() always tracks the string end. When !__testin, 00267 // for the correct functioning of the streambuf inlines 00268 // the other get area pointers are identical. 00269 if (!__testin) 00270 this->setg(__endg, __endg, __endg); 00271 } 00272 } 00273 00274 template <class _CharT, class _Traits, class _Alloc> 00275 void 00276 basic_stringbuf<_CharT, _Traits, _Alloc>:: 00277 _M_pbump(char_type* __pbeg, char_type* __pend, off_type __off) 00278 { 00279 this->setp(__pbeg, __pend); 00280 while (__off > __gnu_cxx::__numeric_traits<int>::__max) 00281 { 00282 this->pbump(__gnu_cxx::__numeric_traits<int>::__max); 00283 __off -= __gnu_cxx::__numeric_traits<int>::__max; 00284 } 00285 this->pbump(__off); 00286 } 00287 00288 // Inhibit implicit instantiations for required instantiations, 00289 // which are defined via explicit instantiations elsewhere. 00290 #if _GLIBCXX_EXTERN_TEMPLATE 00291 extern template class basic_stringbuf<char>; 00292 extern template class basic_istringstream<char>; 00293 extern template class basic_ostringstream<char>; 00294 extern template class basic_stringstream<char>; 00295 00296 #ifdef _GLIBCXX_USE_WCHAR_T 00297 extern template class basic_stringbuf<wchar_t>; 00298 extern template class basic_istringstream<wchar_t>; 00299 extern template class basic_ostringstream<wchar_t>; 00300 extern template class basic_stringstream<wchar_t>; 00301 #endif 00302 #endif 00303 00304 _GLIBCXX_END_NAMESPACE_VERSION 00305 } // namespace std 00306 00307 #endif