libstdc++
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00001 // String based streams -*- C++ -*- 00002 00003 // Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 00004 // 2006, 2007, 2009 00005 // Free Software Foundation, Inc. 00006 // 00007 // This file is part of the GNU ISO C++ Library. This library is free 00008 // software; you can redistribute it and/or modify it under the 00009 // terms of the GNU General Public License as published by the 00010 // Free Software Foundation; either version 3, or (at your option) 00011 // any later version. 00012 00013 // This library is distributed in the hope that it will be useful, 00014 // but WITHOUT ANY WARRANTY; without even the implied warranty of 00015 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00016 // GNU General Public License for more details. 00017 00018 // Under Section 7 of GPL version 3, you are granted additional 00019 // permissions described in the GCC Runtime Library Exception, version 00020 // 3.1, as published by the Free Software Foundation. 00021 00022 // You should have received a copy of the GNU General Public License and 00023 // a copy of the GCC Runtime Library Exception along with this program; 00024 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 00025 // <http://www.gnu.org/licenses/>. 00026 00027 /** @file sstream.tcc 00028 * This is an internal header file, included by other library headers. 00029 * You should not attempt to use it directly. 00030 */ 00031 00032 // 00033 // ISO C++ 14882: 27.7 String-based streams 00034 // 00035 00036 #ifndef _SSTREAM_TCC 00037 #define _SSTREAM_TCC 1 00038 00039 #pragma GCC system_header 00040 00041 _GLIBCXX_BEGIN_NAMESPACE(std) 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 const __size_type __max_size = _M_string.max_size(); 00092 const bool __testput = this->pptr() < this->epptr(); 00093 if (__builtin_expect(!__testput && __capacity == __max_size, false)) 00094 return traits_type::eof(); 00095 00096 // Try to append __c into output sequence in one of two ways. 00097 // Order these tests done in is unspecified by the standard. 00098 const char_type __conv = traits_type::to_char_type(__c); 00099 if (!__testput) 00100 { 00101 // NB: Start ostringstream buffers at 512 chars. This is an 00102 // experimental value (pronounced "arbitrary" in some of the 00103 // hipper English-speaking countries), and can be changed to 00104 // suit particular needs. 00105 // 00106 // _GLIBCXX_RESOLVE_LIB_DEFECTS 00107 // 169. Bad efficiency of overflow() mandated 00108 // 432. stringbuf::overflow() makes only one write position 00109 // available 00110 const __size_type __opt_len = std::max(__size_type(2 * __capacity), 00111 __size_type(512)); 00112 const __size_type __len = std::min(__opt_len, __max_size); 00113 __string_type __tmp; 00114 __tmp.reserve(__len); 00115 if (this->pbase()) 00116 __tmp.assign(this->pbase(), this->epptr() - this->pbase()); 00117 __tmp.push_back(__conv); 00118 _M_string.swap(__tmp); 00119 _M_sync(const_cast<char_type*>(_M_string.data()), 00120 this->gptr() - this->eback(), this->pptr() - this->pbase()); 00121 } 00122 else 00123 *this->pptr() = __conv; 00124 this->pbump(1); 00125 return __c; 00126 } 00127 00128 template <class _CharT, class _Traits, class _Alloc> 00129 typename basic_stringbuf<_CharT, _Traits, _Alloc>::int_type 00130 basic_stringbuf<_CharT, _Traits, _Alloc>:: 00131 underflow() 00132 { 00133 int_type __ret = traits_type::eof(); 00134 const bool __testin = this->_M_mode & ios_base::in; 00135 if (__testin) 00136 { 00137 // Update egptr() to match the actual string end. 00138 _M_update_egptr(); 00139 00140 if (this->gptr() < this->egptr()) 00141 __ret = traits_type::to_int_type(*this->gptr()); 00142 } 00143 return __ret; 00144 } 00145 00146 template <class _CharT, class _Traits, class _Alloc> 00147 typename basic_stringbuf<_CharT, _Traits, _Alloc>::pos_type 00148 basic_stringbuf<_CharT, _Traits, _Alloc>:: 00149 seekoff(off_type __off, ios_base::seekdir __way, ios_base::openmode __mode) 00150 { 00151 pos_type __ret = pos_type(off_type(-1)); 00152 bool __testin = (ios_base::in & this->_M_mode & __mode) != 0; 00153 bool __testout = (ios_base::out & this->_M_mode & __mode) != 0; 00154 const bool __testboth = __testin && __testout && __way != ios_base::cur; 00155 __testin &= !(__mode & ios_base::out); 00156 __testout &= !(__mode & ios_base::in); 00157 00158 // _GLIBCXX_RESOLVE_LIB_DEFECTS 00159 // 453. basic_stringbuf::seekoff need not always fail for an empty stream. 00160 const char_type* __beg = __testin ? this->eback() : this->pbase(); 00161 if ((__beg || !__off) && (__testin || __testout || __testboth)) 00162 { 00163 _M_update_egptr(); 00164 00165 off_type __newoffi = __off; 00166 off_type __newoffo = __newoffi; 00167 if (__way == ios_base::cur) 00168 { 00169 __newoffi += this->gptr() - __beg; 00170 __newoffo += this->pptr() - __beg; 00171 } 00172 else if (__way == ios_base::end) 00173 __newoffo = __newoffi += this->egptr() - __beg; 00174 00175 if ((__testin || __testboth) 00176 && __newoffi >= 0 00177 && this->egptr() - __beg >= __newoffi) 00178 { 00179 this->gbump((__beg + __newoffi) - this->gptr()); 00180 __ret = pos_type(__newoffi); 00181 } 00182 if ((__testout || __testboth) 00183 && __newoffo >= 0 00184 && this->egptr() - __beg >= __newoffo) 00185 { 00186 this->pbump((__beg + __newoffo) - this->pptr()); 00187 __ret = pos_type(__newoffo); 00188 } 00189 } 00190 return __ret; 00191 } 00192 00193 template <class _CharT, class _Traits, class _Alloc> 00194 typename basic_stringbuf<_CharT, _Traits, _Alloc>::pos_type 00195 basic_stringbuf<_CharT, _Traits, _Alloc>:: 00196 seekpos(pos_type __sp, ios_base::openmode __mode) 00197 { 00198 pos_type __ret = pos_type(off_type(-1)); 00199 const bool __testin = (ios_base::in & this->_M_mode & __mode) != 0; 00200 const bool __testout = (ios_base::out & this->_M_mode & __mode) != 0; 00201 00202 const char_type* __beg = __testin ? this->eback() : this->pbase(); 00203 if ((__beg || !off_type(__sp)) && (__testin || __testout)) 00204 { 00205 _M_update_egptr(); 00206 00207 const off_type __pos(__sp); 00208 const bool __testpos = (0 <= __pos 00209 && __pos <= this->egptr() - __beg); 00210 if (__testpos) 00211 { 00212 if (__testin) 00213 this->gbump((__beg + __pos) - this->gptr()); 00214 if (__testout) 00215 this->pbump((__beg + __pos) - this->pptr()); 00216 __ret = __sp; 00217 } 00218 } 00219 return __ret; 00220 } 00221 00222 template <class _CharT, class _Traits, class _Alloc> 00223 void 00224 basic_stringbuf<_CharT, _Traits, _Alloc>:: 00225 _M_sync(char_type* __base, __size_type __i, __size_type __o) 00226 { 00227 const bool __testin = _M_mode & ios_base::in; 00228 const bool __testout = _M_mode & ios_base::out; 00229 char_type* __endg = __base + _M_string.size(); 00230 char_type* __endp = __base + _M_string.capacity(); 00231 00232 if (__base != _M_string.data()) 00233 { 00234 // setbuf: __i == size of buffer area (_M_string.size() == 0). 00235 __endg += __i; 00236 __i = 0; 00237 __endp = __endg; 00238 } 00239 00240 if (__testin) 00241 this->setg(__base, __base + __i, __endg); 00242 if (__testout) 00243 { 00244 this->setp(__base, __endp); 00245 this->pbump(__o); 00246 // egptr() always tracks the string end. When !__testin, 00247 // for the correct functioning of the streambuf inlines 00248 // the other get area pointers are identical. 00249 if (!__testin) 00250 this->setg(__endg, __endg, __endg); 00251 } 00252 } 00253 00254 // Inhibit implicit instantiations for required instantiations, 00255 // which are defined via explicit instantiations elsewhere. 00256 // NB: This syntax is a GNU extension. 00257 #if _GLIBCXX_EXTERN_TEMPLATE 00258 extern template class basic_stringbuf<char>; 00259 extern template class basic_istringstream<char>; 00260 extern template class basic_ostringstream<char>; 00261 extern template class basic_stringstream<char>; 00262 00263 #ifdef _GLIBCXX_USE_WCHAR_T 00264 extern template class basic_stringbuf<wchar_t>; 00265 extern template class basic_istringstream<wchar_t>; 00266 extern template class basic_ostringstream<wchar_t>; 00267 extern template class basic_stringstream<wchar_t>; 00268 #endif 00269 #endif 00270 00271 _GLIBCXX_END_NAMESPACE 00272 00273 #endif