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The C and C++ Include Header Files
cat -n /usr/include/c++/15/bits/locale_classes.tcc
1 // Locale support -*- C++ -*- 2 3 // Copyright (C) 2007-2025 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/locale_classes.tcc 26 * This is an internal header file, included by other library headers. 27 * Do not attempt to use it directly. @headername{locale} 28 */ 29 30 // 31 // ISO C++ 14882: 22.1 Locales 32 // 33 34 #ifndef _LOCALE_CLASSES_TCC 35 #define _LOCALE_CLASSES_TCC 1 36 37 #ifdef _GLIBCXX_SYSHDR 38 #pragma GCC system_header 39 #endif 40 41 #include <cerrno> 42 43 #pragma GCC diagnostic push 44 #pragma GCC diagnostic ignored "-Wc++11-extensions" // extern template 45 #pragma GCC diagnostic ignored "-Wvariadic-macros" 46 47 namespace std _GLIBCXX_VISIBILITY(default) 48 { 49 _GLIBCXX_BEGIN_NAMESPACE_VERSION 50 51 template<typename _Facet> 52 locale:: 53 locale(const locale& __other, _Facet* __f) 54 { 55 // _GLIBCXX_RESOLVE_LIB_DEFECTS 56 // 2295. Locale name when the provided Facet is a nullptr 57 if (__builtin_expect(!__f, 0)) 58 { 59 _M_impl = __other._M_impl; 60 _M_impl->_M_add_reference(); 61 return; 62 } 63 64 _M_impl = new _Impl(*__other._M_impl, 1); 65 66 __try 67 { _M_impl->_M_install_facet(&_Facet::id, __f); } 68 __catch(...) 69 { 70 _M_impl->_M_remove_reference(); 71 __throw_exception_again; 72 } 73 delete [] _M_impl->_M_names[0]; 74 _M_impl->_M_names[0] = 0; // Unnamed. 75 } 76 77 template<typename _Facet> 78 locale 79 locale:: 80 combine(const locale& __other) const 81 { 82 #if __cpp_lib_type_trait_variable_templates // C++ >= 17 83 static_assert(__is_facet<_Facet>, "Template argument must be a facet"); 84 #endif 85 86 _Impl* __tmp = new _Impl(*_M_impl, 1); 87 __try 88 { 89 __tmp->_M_replace_facet(__other._M_impl, &_Facet::id); 90 } 91 __catch(...) 92 { 93 __tmp->_M_remove_reference(); 94 __throw_exception_again; 95 } 96 delete[] __tmp->_M_names[0]; 97 __tmp->_M_names[0] = 0; // Unnamed. 98 return locale(__tmp); 99 } 100 101 template<typename _CharT, typename _Traits, typename _Alloc> 102 bool 103 locale:: 104 operator()(const basic_string<_CharT, _Traits, _Alloc>& __s1, 105 const basic_string<_CharT, _Traits, _Alloc>& __s2) const 106 { 107 typedef std::collate<_CharT> __collate_type; 108 const __collate_type& __collate = use_facet<__collate_type>(*this); 109 return (__collate.compare(__s1.data(), __s1.data() + __s1.length(), 110 __s2.data(), __s2.data() + __s2.length()) < 0); 111 } 112 113 #pragma GCC diagnostic push 114 #pragma GCC diagnostic ignored "-Wc++17-extensions" 115 template<typename _Facet> 116 inline const _Facet* 117 __try_use_facet(const locale& __loc) _GLIBCXX_NOTHROW 118 { 119 const size_t __i = _Facet::id._M_id(); 120 const locale::facet** __facets = __loc._M_impl->_M_facets; 121 122 // We know these standard facets are always installed in every locale 123 // so dynamic_cast always succeeds, just use static_cast instead. 124 #define _GLIBCXX_STD_FACET(...) \ 125 if _GLIBCXX_CONSTEXPR (__is_same(const _Facet, const __VA_ARGS__)) \ 126 return static_cast<const _Facet*>(__facets[__i]) 127 128 _GLIBCXX_STD_FACET(ctype<char>); 129 _GLIBCXX_STD_FACET(num_get<char>); 130 _GLIBCXX_STD_FACET(num_put<char>); 131 _GLIBCXX_STD_FACET(codecvt<char, char, mbstate_t>); 132 _GLIBCXX_STD_FACET(collate<char>); 133 _GLIBCXX_STD_FACET(moneypunct<char>); 134 _GLIBCXX_STD_FACET(moneypunct<char, true>); 135 _GLIBCXX_STD_FACET(money_get<char>); 136 _GLIBCXX_STD_FACET(money_put<char>); 137 _GLIBCXX_STD_FACET(numpunct<char>); 138 _GLIBCXX_STD_FACET(time_get<char>); 139 _GLIBCXX_STD_FACET(time_put<char>); 140 _GLIBCXX_STD_FACET(messages<char>); 141 142 #ifdef _GLIBCXX_USE_WCHAR_T 143 _GLIBCXX_STD_FACET(ctype<wchar_t>); 144 _GLIBCXX_STD_FACET(num_get<wchar_t>); 145 _GLIBCXX_STD_FACET(num_put<wchar_t>); 146 _GLIBCXX_STD_FACET(codecvt<wchar_t, char, mbstate_t>); 147 _GLIBCXX_STD_FACET(collate<wchar_t>); 148 _GLIBCXX_STD_FACET(moneypunct<wchar_t>); 149 _GLIBCXX_STD_FACET(moneypunct<wchar_t, true>); 150 _GLIBCXX_STD_FACET(money_get<wchar_t>); 151 _GLIBCXX_STD_FACET(money_put<wchar_t>); 152 _GLIBCXX_STD_FACET(numpunct<wchar_t>); 153 _GLIBCXX_STD_FACET(time_get<wchar_t>); 154 _GLIBCXX_STD_FACET(time_put<wchar_t>); 155 _GLIBCXX_STD_FACET(messages<wchar_t>); 156 #endif 157 #if __cplusplus >= 201103L 158 _GLIBCXX_STD_FACET(codecvt<char16_t, char, mbstate_t>); 159 _GLIBCXX_STD_FACET(codecvt<char32_t, char, mbstate_t>); 160 #endif 161 162 #undef _GLIBCXX_STD_FACET 163 164 if (__i >= __loc._M_impl->_M_facets_size || !__facets[__i]) 165 return 0; 166 167 #if __cpp_rtti 168 return dynamic_cast<const _Facet*>(__facets[__i]); 169 #else 170 return static_cast<const _Facet*>(__facets[__i]); 171 #endif 172 } 173 #pragma GCC diagnostic pop 174 175 /** 176 * @brief Test for the presence of a facet. 177 * @ingroup locales 178 * 179 * has_facet tests the locale argument for the presence of the facet type 180 * provided as the template parameter. Facets derived from the facet 181 * parameter will also return true. 182 * 183 * @tparam _Facet The facet type to test the presence of. 184 * @param __loc The locale to test. 185 * @return true if @p __loc contains a facet of type _Facet, else false. 186 */ 187 template<typename _Facet> 188 _GLIBCXX_NODISCARD 189 inline bool 190 has_facet(const locale& __loc) _GLIBCXX_USE_NOEXCEPT 191 { 192 #if __cplusplus >= 201103L 193 static_assert(__is_base_of(locale::facet, _Facet), 194 "template argument must be derived from locale::facet"); 195 #else 196 (void) static_cast<const _Facet*>(static_cast<const locale::facet*>(0)); 197 #endif 198 return std::__try_use_facet<_Facet>(__loc) != 0; 199 } 200 201 /** 202 * @brief Return a facet. 203 * @ingroup locales 204 * 205 * use_facet looks for and returns a reference to a facet of type Facet 206 * where Facet is the template parameter. If has_facet(locale) is true, 207 * there is a suitable facet to return. It throws std::bad_cast if the 208 * locale doesn't contain a facet of type Facet. 209 * 210 * @tparam _Facet The facet type to access. 211 * @param __loc The locale to use. 212 * @return Reference to facet of type Facet. 213 * @throw std::bad_cast if @p __loc doesn't contain a facet of type _Facet. 214 */ 215 #pragma GCC diagnostic push 216 #pragma GCC diagnostic ignored "-Wdangling-reference" 217 template<typename _Facet> 218 _GLIBCXX_NODISCARD 219 inline const _Facet& 220 use_facet(const locale& __loc) 221 { 222 #if __cplusplus >= 201103L 223 static_assert(__is_base_of(locale::facet, _Facet), 224 "template argument must be derived from locale::facet"); 225 #else 226 (void) static_cast<const _Facet*>(static_cast<const locale::facet*>(0)); 227 #endif 228 if (const _Facet* __f = std::__try_use_facet<_Facet>(__loc)) 229 return *__f; 230 __throw_bad_cast(); 231 } 232 #pragma GCC diagnostic pop 233 234 235 // Generic version does nothing. 236 template<typename _CharT> 237 int 238 collate<_CharT>::_M_compare(const _CharT*, const _CharT*) const throw () 239 { return 0; } 240 241 // Generic version does nothing. 242 template<typename _CharT> 243 size_t 244 collate<_CharT>::_M_transform(_CharT*, const _CharT*, size_t) const throw () 245 { return 0; } 246 247 template<typename _CharT> 248 int 249 collate<_CharT>:: 250 do_compare(const _CharT* __lo1, const _CharT* __hi1, 251 const _CharT* __lo2, const _CharT* __hi2) const 252 { 253 // strcoll assumes zero-terminated strings so we make a copy 254 // and then put a zero at the end. 255 const string_type __one(__lo1, __hi1); 256 const string_type __two(__lo2, __hi2); 257 258 const _CharT* __p = __one.c_str(); 259 const _CharT* __pend = __one.data() + __one.length(); 260 const _CharT* __q = __two.c_str(); 261 const _CharT* __qend = __two.data() + __two.length(); 262 263 // strcoll stops when it sees a nul character so we break 264 // the strings into zero-terminated substrings and pass those 265 // to strcoll. 266 for (;;) 267 { 268 const int __res = _M_compare(__p, __q); 269 if (__res) 270 return __res; 271 272 __p += char_traits<_CharT>::length(__p); 273 __q += char_traits<_CharT>::length(__q); 274 if (__p == __pend && __q == __qend) 275 return 0; 276 else if (__p == __pend) 277 return -1; 278 else if (__q == __qend) 279 return 1; 280 281 __p++; 282 __q++; 283 } 284 } 285 286 template<typename _CharT> 287 typename collate<_CharT>::string_type 288 collate<_CharT>:: 289 do_transform(const _CharT* __lo, const _CharT* __hi) const 290 { 291 string_type __ret; 292 293 // strxfrm assumes zero-terminated strings so we make a copy 294 const string_type __str(__lo, __hi); 295 296 const _CharT* __p = __str.c_str(); 297 const _CharT* __pend = __str.data() + __str.length(); 298 299 size_t __len = (__hi - __lo) * 2; 300 301 struct _Buf 302 { 303 _Buf(size_t __n, void* __buf, int __e) 304 : _M_c(__buf ? (_CharT*)__buf : new _CharT[__n]), 305 _M_stackbuf(__buf), 306 _M_errno(__e) 307 { } 308 309 ~_Buf() 310 { 311 if (_M_c != _M_stackbuf) 312 delete[] _M_c; 313 if (errno == 0) 314 errno = _M_errno; 315 } 316 317 void _M_realloc(size_t __len) 318 { 319 _CharT* __p = new _CharT[__len]; 320 if (_M_c != _M_stackbuf) 321 delete[] _M_c; 322 _M_c = __p; 323 } 324 325 _CharT* _M_c; 326 void* const _M_stackbuf; 327 int _M_errno; 328 }; 329 330 const size_t __bytes = __len * sizeof(_CharT); 331 _Buf __buf(__len, __bytes <= 256 ? __builtin_alloca(__bytes) : 0, errno); 332 errno = 0; 333 334 // strxfrm stops when it sees a nul character so we break 335 // the string into zero-terminated substrings and pass those 336 // to strxfrm. 337 for (;;) 338 { 339 // First try a buffer perhaps big enough. 340 size_t __res = _M_transform(__buf._M_c, __p, __len); 341 // If the buffer was not large enough, try again with the 342 // correct size. 343 if (__res >= __len) 344 { 345 if (__builtin_expect(errno, 0)) 346 { 347 #if __cpp_exceptions 348 __throw_system_error(errno); 349 #else 350 // std::regex can call this function internally with 351 // char values that always fail, so we don't want to 352 // use _GLIBCXX_THROW_OR_ABORT here. 353 __ret.clear(); 354 break; 355 #endif 356 } 357 358 __len = __res + 1; 359 __buf._M_realloc(__len); 360 __res = _M_transform(__buf._M_c, __p, __len); 361 } 362 363 __ret.append(__buf._M_c, __res); 364 __p += char_traits<_CharT>::length(__p); 365 if (__p == __pend) 366 break; 367 368 __p++; 369 __ret.push_back(_CharT()); 370 } 371 372 return __ret; 373 } 374 375 template<typename _CharT> 376 long 377 collate<_CharT>:: 378 do_hash(const _CharT* __lo, const _CharT* __hi) const 379 { 380 unsigned long __val = 0; 381 for (; __lo < __hi; ++__lo) 382 __val = 383 *__lo + ((__val << 7) 384 | (__val >> (__gnu_cxx::__numeric_traits<unsigned long>:: 385 __digits - 7))); 386 return static_cast<long>(__val); 387 } 388 389 // Inhibit implicit instantiations for required instantiations, 390 // which are defined via explicit instantiations elsewhere. 391 #if _GLIBCXX_EXTERN_TEMPLATE 392 extern template class collate<char>; 393 extern template class collate_byname<char>; 394 395 extern template 396 const collate<char>* 397 __try_use_facet<collate<char> >(const locale&) _GLIBCXX_NOTHROW; 398 399 extern template 400 const collate<char>& 401 use_facet<collate<char> >(const locale&); 402 403 extern template 404 bool 405 has_facet<collate<char> >(const locale&); 406 407 #ifdef _GLIBCXX_USE_WCHAR_T 408 extern template class collate<wchar_t>; 409 extern template class collate_byname<wchar_t>; 410 411 extern template 412 const collate<wchar_t>* 413 __try_use_facet<collate<wchar_t> >(const locale&) _GLIBCXX_NOTHROW; 414 415 extern template 416 const collate<wchar_t>& 417 use_facet<collate<wchar_t> >(const locale&); 418 419 extern template 420 bool 421 has_facet<collate<wchar_t> >(const locale&); 422 #endif 423 #endif 424 425 _GLIBCXX_END_NAMESPACE_VERSION 426 } // namespace std 427 428 #pragma GCC diagnostic pop 429 #endif
