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1 // Locale support -*- C++ -*- 2 3 // Copyright (C) 1997-2025 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.h 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_H 35 #define _LOCALE_CLASSES_H 1 36 37 #ifdef _GLIBCXX_SYSHDR 38 #pragma GCC system_header 39 #endif 40 41 #include <bits/localefwd.h> 42 #include <string> 43 #include <ext/atomicity.h> 44 45 #ifdef __glibcxx_text_encoding 46 #include <text_encoding> 47 #endif 48 49 namespace std _GLIBCXX_VISIBILITY(default) 50 { 51 _GLIBCXX_BEGIN_NAMESPACE_VERSION 52 53 // 22.1.1 Class locale 54 /** 55 * @brief Container class for localization functionality. 56 * @ingroup locales 57 * 58 * The locale class is first a class wrapper for C library locales. It is 59 * also an extensible container for user-defined localization. A locale is 60 * a collection of facets that implement various localization features such 61 * as money, time, and number printing. 62 * 63 * Constructing C++ locales does not change the C library locale. 64 * 65 * This library supports efficient construction and copying of locales 66 * through a reference counting implementation of the locale class. 67 */ 68 class locale 69 { 70 public: 71 // Types: 72 /// Definition of locale::category. 73 typedef int category; 74 75 // Forward decls and friends: 76 class facet; 77 class id; 78 class _Impl; 79 80 friend class facet; 81 friend class _Impl; 82 83 template<typename _Facet> 84 friend bool 85 has_facet(const locale&) throw(); 86 87 template<typename _Facet> 88 friend const _Facet& 89 use_facet(const locale&); 90 91 template<typename _Facet> 92 friend const _Facet* 93 __try_use_facet(const locale&) _GLIBCXX_NOTHROW; 94 95 template<typename _Cache> 96 friend struct __use_cache; 97 98 ///@{ 99 /** 100 * @brief Category values. 101 * 102 * The standard category values are none, ctype, numeric, collate, time, 103 * monetary, and messages. They form a bitmask that supports union and 104 * intersection. The category all is the union of these values. 105 * 106 * NB: Order must match _S_facet_categories definition in locale.cc 107 */ 108 static const category none = 0; 109 static const category ctype = 1L << 0; 110 static const category numeric = 1L << 1; 111 static const category collate = 1L << 2; 112 static const category time = 1L << 3; 113 static const category monetary = 1L << 4; 114 static const category messages = 1L << 5; 115 static const category all = (ctype | numeric | collate | 116 time | monetary | messages); 117 ///@} 118 119 // Construct/copy/destroy: 120 121 /** 122 * @brief Default constructor. 123 * 124 * Constructs a copy of the global locale. If no locale has been 125 * explicitly set, this is the C locale. 126 */ 127 locale() throw(); 128 129 /** 130 * @brief Copy constructor. 131 * 132 * Constructs a copy of @a other. 133 * 134 * @param __other The locale to copy. 135 */ 136 locale(const locale& __other) throw(); 137 138 /** 139 * @brief Named locale constructor. 140 * 141 * Constructs a copy of the named C library locale. 142 * 143 * @param __s Name of the locale to construct. 144 * @throw std::runtime_error if __s is null or an undefined locale. 145 */ 146 explicit 147 locale(const char* __s); 148 149 /** 150 * @brief Construct locale with facets from another locale. 151 * 152 * Constructs a copy of the locale @a base. The facets specified by @a 153 * cat are replaced with those from the locale named by @a s. If base is 154 * named, this locale instance will also be named. 155 * 156 * @param __base The locale to copy. 157 * @param __s Name of the locale to use facets from. 158 * @param __cat Set of categories defining the facets to use from __s. 159 * @throw std::runtime_error if __s is null or an undefined locale. 160 */ 161 locale(const locale& __base, const char* __s, category __cat); 162 163 #if __cplusplus >= 201103L 164 /** 165 * @brief Named locale constructor. 166 * 167 * Constructs a copy of the named C library locale. 168 * 169 * @param __s Name of the locale to construct. 170 * @throw std::runtime_error if __s is an undefined locale. 171 */ 172 explicit 173 locale(const std::string& __s) : locale(__s.c_str()) { } 174 175 /** 176 * @brief Construct locale with facets from another locale. 177 * 178 * Constructs a copy of the locale @a base. The facets specified by @a 179 * cat are replaced with those from the locale named by @a s. If base is 180 * named, this locale instance will also be named. 181 * 182 * @param __base The locale to copy. 183 * @param __s Name of the locale to use facets from. 184 * @param __cat Set of categories defining the facets to use from __s. 185 * @throw std::runtime_error if __s is an undefined locale. 186 */ 187 locale(const locale& __base, const std::string& __s, category __cat) 188 : locale(__base, __s.c_str(), __cat) { } 189 #endif 190 191 /** 192 * @brief Construct locale with facets from another locale. 193 * 194 * Constructs a copy of the locale @a base. The facets specified by @a 195 * cat are replaced with those from the locale @a add. If @a base and @a 196 * add are named, this locale instance will also be named. 197 * 198 * @param __base The locale to copy. 199 * @param __add The locale to use facets from. 200 * @param __cat Set of categories defining the facets to use from add. 201 */ 202 locale(const locale& __base, const locale& __add, category __cat); 203 204 /** 205 * @brief Construct locale with another facet. 206 * 207 * Constructs a copy of the locale @a __other. The facet @a __f 208 * is added to @a __other, replacing an existing facet of type 209 * Facet if there is one. If @a __f is null, this locale is a 210 * copy of @a __other. 211 * 212 * @param __other The locale to copy. 213 * @param __f The facet to add in. 214 */ 215 template<typename _Facet> 216 locale(const locale& __other, _Facet* __f); 217 218 /// Locale destructor. 219 ~locale() throw(); 220 221 /** 222 * @brief Assignment operator. 223 * 224 * Set this locale to be a copy of @a other. 225 * 226 * @param __other The locale to copy. 227 * @return A reference to this locale. 228 */ 229 const locale& 230 operator=(const locale& __other) throw(); 231 232 /** 233 * @brief Construct locale with another facet. 234 * 235 * Constructs and returns a new copy of this locale. Adds or replaces an 236 * existing facet of type Facet from the locale @a other into the new 237 * locale. 238 * 239 * @tparam _Facet The facet type to copy from other 240 * @param __other The locale to copy from. 241 * @return Newly constructed locale. 242 * @throw std::runtime_error if __other has no facet of type _Facet. 243 */ 244 template<typename _Facet> 245 _GLIBCXX_NODISCARD 246 locale 247 combine(const locale& __other) const; 248 249 // Locale operations: 250 /** 251 * @brief Return locale name. 252 * @return Locale name or "*" if unnamed. 253 */ 254 _GLIBCXX_NODISCARD _GLIBCXX_DEFAULT_ABI_TAG 255 string 256 name() const; 257 258 #ifdef __glibcxx_text_encoding 259 # if __CHAR_BIT__ == 8 260 text_encoding 261 encoding() const; 262 # else 263 text_encoding 264 encoding() const = delete; 265 # endif 266 #endif 267 268 /** 269 * @brief Locale equality. 270 * 271 * @param __other The locale to compare against. 272 * @return True if other and this refer to the same locale instance, are 273 * copies, or have the same name. False otherwise. 274 */ 275 _GLIBCXX_NODISCARD 276 bool 277 operator==(const locale& __other) const throw(); 278 279 #if __cpp_impl_three_way_comparison < 201907L 280 /** 281 * @brief Locale inequality. 282 * 283 * @param __other The locale to compare against. 284 * @return ! (*this == __other) 285 */ 286 _GLIBCXX_NODISCARD 287 bool 288 operator!=(const locale& __other) const throw() 289 { return !(this->operator==(__other)); } 290 #endif 291 292 /** 293 * @brief Compare two strings according to collate. 294 * 295 * Template operator to compare two strings using the compare function of 296 * the collate facet in this locale. One use is to provide the locale to 297 * the sort function. For example, a vector v of strings could be sorted 298 * according to locale loc by doing: 299 * @code 300 * std::sort(v.begin(), v.end(), loc); 301 * @endcode 302 * 303 * @param __s1 First string to compare. 304 * @param __s2 Second string to compare. 305 * @return True if collate<_Char> facet compares __s1 < __s2, else false. 306 */ 307 template<typename _Char, typename _Traits, typename _Alloc> 308 _GLIBCXX_NODISCARD 309 bool 310 operator()(const basic_string<_Char, _Traits, _Alloc>& __s1, 311 const basic_string<_Char, _Traits, _Alloc>& __s2) const; 312 313 // Global locale objects: 314 /** 315 * @brief Set global locale 316 * 317 * This function sets the global locale to the argument and returns a 318 * copy of the previous global locale. If the argument has a name, it 319 * will also call std::setlocale(LC_ALL, loc.name()). 320 * 321 * @param __loc The new locale to make global. 322 * @return Copy of the old global locale. 323 */ 324 static locale 325 global(const locale& __loc); 326 327 /** 328 * @brief Return reference to the C locale. 329 */ 330 _GLIBCXX_NODISCARD 331 static const locale& 332 classic(); 333 334 private: 335 // The (shared) implementation 336 _Impl* _M_impl; 337 338 // The "C" reference locale 339 static _Impl* _S_classic; 340 341 // Current global locale 342 static _Impl* _S_global; 343 344 // Names of underlying locale categories. 345 // NB: locale::global() has to know how to modify all the 346 // underlying categories, not just the ones required by the C++ 347 // standard. 348 static const char* const* const _S_categories; 349 350 // Number of standard categories. For C++, these categories are 351 // collate, ctype, monetary, numeric, time, and messages. These 352 // directly correspond to ISO C99 macros LC_COLLATE, LC_CTYPE, 353 // LC_MONETARY, LC_NUMERIC, and LC_TIME. In addition, POSIX (IEEE 354 // 1003.1-2001) specifies LC_MESSAGES. 355 // In addition to the standard categories, the underlying 356 // operating system is allowed to define extra LC_* 357 // macros. For GNU systems, the following are also valid: 358 // LC_PAPER, LC_NAME, LC_ADDRESS, LC_TELEPHONE, LC_MEASUREMENT, 359 // and LC_IDENTIFICATION. 360 enum { _S_categories_size = 6 + _GLIBCXX_NUM_CATEGORIES }; 361 362 #ifdef __GTHREADS 363 static __gthread_once_t _S_once; 364 #endif 365 366 explicit 367 locale(_Impl*) throw(); 368 369 static void 370 _S_initialize(); 371 372 static void 373 _S_initialize_once() throw(); 374 375 static category 376 _S_normalize_category(category); 377 378 void 379 _M_coalesce(const locale& __base, const locale& __add, category __cat); 380 381 #if _GLIBCXX_USE_CXX11_ABI 382 static const id* const _S_twinned_facets[]; 383 #endif 384 }; 385 386 #if __cpp_lib_type_trait_variable_templates // C++ >= 17 387 template<typename _Tp> 388 constexpr bool __is_facet = is_base_of_v<locale::facet, _Tp>; 389 template<typename _Tp> 390 constexpr bool __is_facet<volatile _Tp> = false; 391 #endif 392 393 // 22.1.1.1.2 Class locale::facet 394 /** 395 * @brief Localization functionality base class. 396 * @ingroup locales 397 * 398 * The facet class is the base class for a localization feature, such as 399 * money, time, and number printing. It provides common support for facets 400 * and reference management. 401 * 402 * Facets may not be copied or assigned. 403 */ 404 class locale::facet 405 { 406 private: 407 friend class locale; 408 friend class locale::_Impl; 409 410 mutable _Atomic_word _M_refcount; 411 412 // Contains data from the underlying "C" library for the classic locale. 413 static __c_locale _S_c_locale; 414 415 // String literal for the name of the classic locale. 416 static const char _S_c_name[2]; 417 418 #ifdef __GTHREADS 419 static __gthread_once_t _S_once; 420 #endif 421 422 static void 423 _S_initialize_once(); 424 425 protected: 426 /** 427 * @brief Facet constructor. 428 * 429 * This is the constructor provided by the standard. If refs is 0, the 430 * facet is destroyed when the last referencing locale is destroyed. 431 * Otherwise the facet will never be destroyed. 432 * 433 * @param __refs The initial value for reference count. 434 */ 435 explicit 436 facet(size_t __refs = 0) throw() : _M_refcount(__refs ? 1 : 0) 437 { } 438 439 /// Facet destructor. 440 virtual 441 ~facet(); 442 443 static void 444 _S_create_c_locale(__c_locale& __cloc, const char* __s, 445 __c_locale __old = 0); 446 447 static __c_locale 448 _S_clone_c_locale(__c_locale& __cloc) throw(); 449 450 static void 451 _S_destroy_c_locale(__c_locale& __cloc); 452 453 static __c_locale 454 _S_lc_ctype_c_locale(__c_locale __cloc, const char* __s); 455 456 // Returns data from the underlying "C" library data for the 457 // classic locale. 458 static __c_locale 459 _S_get_c_locale(); 460 461 _GLIBCXX_CONST static const char* 462 _S_get_c_name() throw(); 463 464 #if __cplusplus < 201103L 465 private: 466 facet(const facet&); // Not defined. 467 468 facet& 469 operator=(const facet&); // Not defined. 470 #else 471 facet(const facet&) = delete; 472 473 facet& 474 operator=(const facet&) = delete; 475 #endif 476 477 private: 478 void 479 _M_add_reference() const throw() 480 { __gnu_cxx::__atomic_add_dispatch(&_M_refcount, 1); } 481 482 void 483 _M_remove_reference() const throw() 484 { 485 // Be race-detector-friendly. For more info see bits/c++config. 486 _GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_M_refcount); 487 if (__gnu_cxx::__exchange_and_add_dispatch(&_M_refcount, -1) == 1) 488 { 489 _GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_M_refcount); 490 __try 491 { delete this; } 492 __catch(...) 493 { } 494 } 495 } 496 497 const facet* _M_sso_shim(const id*) const; 498 const facet* _M_cow_shim(const id*) const; 499 500 protected: 501 class __shim; // For internal use only. 502 }; 503 504 505 // 22.1.1.1.3 Class locale::id 506 /** 507 * @brief Facet ID class. 508 * @ingroup locales 509 * 510 * The ID class provides facets with an index used to identify them. 511 * Every facet class must define a public static member locale::id, or be 512 * derived from a facet that provides this member, otherwise the facet 513 * cannot be used in a locale. The locale::id ensures that each class 514 * type gets a unique identifier. 515 */ 516 class locale::id 517 { 518 private: 519 friend class locale; 520 friend class locale::_Impl; 521 522 template<typename _Facet> 523 friend const _Facet& 524 use_facet(const locale&); 525 526 template<typename _Facet> 527 friend bool 528 has_facet(const locale&) throw(); 529 530 template<typename _Facet> 531 friend const _Facet* 532 __try_use_facet(const locale&) _GLIBCXX_NOTHROW; 533 534 // NB: There is no accessor for _M_index because it may be used 535 // before the constructor is run; the effect of calling a member 536 // function (even an inline) would be undefined. 537 mutable size_t _M_index; 538 539 // Last id number assigned. 540 static _Atomic_word _S_refcount; 541 542 void 543 operator=(const id&); // Not defined. 544 545 id(const id&); // Not defined. 546 547 public: 548 // NB: This class is always a static data member, and thus can be 549 // counted on to be zero-initialized. 550 /// Constructor. 551 id() { } 552 553 size_t 554 _M_id() const throw(); 555 }; 556 557 558 // Implementation object for locale. 559 class locale::_Impl 560 { 561 public: 562 // Friends. 563 friend class locale; 564 friend class locale::facet; 565 566 template<typename _Facet> 567 friend bool 568 has_facet(const locale&) throw(); 569 570 template<typename _Facet> 571 friend const _Facet& 572 use_facet(const locale&); 573 574 template<typename _Facet> 575 friend const _Facet* 576 __try_use_facet(const locale&) _GLIBCXX_NOTHROW; 577 578 template<typename _Cache> 579 friend struct __use_cache; 580 581 private: 582 // Data Members. 583 _Atomic_word _M_refcount; 584 const facet** _M_facets; 585 size_t _M_facets_size; 586 const facet** _M_caches; 587 char** _M_names; 588 static const locale::id* const _S_id_ctype[]; 589 static const locale::id* const _S_id_numeric[]; 590 static const locale::id* const _S_id_collate[]; 591 static const locale::id* const _S_id_time[]; 592 static const locale::id* const _S_id_monetary[]; 593 static const locale::id* const _S_id_messages[]; 594 static const locale::id* const* const _S_facet_categories[]; 595 596 void 597 _M_add_reference() throw() 598 { __gnu_cxx::__atomic_add_dispatch(&_M_refcount, 1); } 599 600 void 601 _M_remove_reference() throw() 602 { 603 // Be race-detector-friendly. For more info see bits/c++config. 604 _GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_M_refcount); 605 if (__gnu_cxx::__exchange_and_add_dispatch(&_M_refcount, -1) == 1) 606 { 607 _GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_M_refcount); 608 __try 609 { delete this; } 610 __catch(...) 611 { } 612 } 613 } 614 615 _Impl(const _Impl&, size_t); 616 _Impl(const char*, size_t); 617 _Impl(size_t) throw(); 618 619 ~_Impl() throw(); 620 621 _Impl(const _Impl&); // Not defined. 622 623 void 624 operator=(const _Impl&); // Not defined. 625 626 bool 627 _M_check_same_name() 628 { 629 bool __ret = true; 630 if (_M_names[1]) 631 // We must actually compare all the _M_names: can be all equal! 632 for (size_t __i = 0; __ret && __i < _S_categories_size - 1; ++__i) 633 __ret = __builtin_strcmp(_M_names[__i], _M_names[__i + 1]) == 0; 634 return __ret; 635 } 636 637 void 638 _M_replace_categories(const _Impl*, category); 639 640 void 641 _M_replace_category(const _Impl*, const locale::id* const*); 642 643 void 644 _M_replace_facet(const _Impl*, const locale::id*); 645 646 void 647 _M_install_facet(const locale::id*, const facet*); 648 649 template<typename _Facet> 650 void 651 _M_init_facet(_Facet* __facet) 652 { _M_install_facet(&_Facet::id, __facet); } 653 654 template<typename _Facet> 655 void 656 _M_init_facet_unchecked(_Facet* __facet) 657 { 658 __facet->_M_add_reference(); 659 _M_facets[_Facet::id._M_id()] = __facet; 660 } 661 662 void 663 _M_install_cache(const facet*, size_t); 664 665 void _M_init_extra(facet**); 666 void _M_init_extra(void*, void*, const char*, const char*); 667 668 #ifdef _GLIBCXX_LONG_DOUBLE_ALT128_COMPAT 669 void _M_init_extra_ldbl128(bool); 670 #endif 671 }; 672 673 674 /** 675 * @brief Facet for localized string comparison. 676 * 677 * This facet encapsulates the code to compare strings in a localized 678 * manner. 679 * 680 * The collate template uses protected virtual functions to provide 681 * the actual results. The public accessors forward the call to 682 * the virtual functions. These virtual functions are hooks for 683 * developers to implement the behavior they require from the 684 * collate facet. 685 */ 686 template<typename _CharT> 687 class _GLIBCXX_NAMESPACE_CXX11 collate : public locale::facet 688 { 689 public: 690 // Types: 691 ///@{ 692 /// Public typedefs 693 typedef _CharT char_type; 694 typedef basic_string<_CharT> string_type; 695 ///@} 696 697 protected: 698 // Underlying "C" library locale information saved from 699 // initialization, needed by collate_byname as well. 700 __c_locale _M_c_locale_collate; 701 702 public: 703 /// Numpunct facet id. 704 static locale::id id; 705 706 /** 707 * @brief Constructor performs initialization. 708 * 709 * This is the constructor provided by the standard. 710 * 711 * @param __refs Passed to the base facet class. 712 */ 713 explicit 714 collate(size_t __refs = 0) 715 : facet(__refs), _M_c_locale_collate(_S_get_c_locale()) 716 { } 717 718 /** 719 * @brief Internal constructor. Not for general use. 720 * 721 * This is a constructor for use by the library itself to set up new 722 * locales. 723 * 724 * @param __cloc The C locale. 725 * @param __refs Passed to the base facet class. 726 */ 727 explicit 728 collate(__c_locale __cloc, size_t __refs = 0) 729 : facet(__refs), _M_c_locale_collate(_S_clone_c_locale(__cloc)) 730 { } 731 732 /** 733 * @brief Compare two strings. 734 * 735 * This function compares two strings and returns the result by calling 736 * collate::do_compare(). 737 * 738 * @param __lo1 Start of string 1. 739 * @param __hi1 End of string 1. 740 * @param __lo2 Start of string 2. 741 * @param __hi2 End of string 2. 742 * @return 1 if string1 > string2, -1 if string1 < string2, else 0. 743 */ 744 int 745 compare(const _CharT* __lo1, const _CharT* __hi1, 746 const _CharT* __lo2, const _CharT* __hi2) const 747 { return this->do_compare(__lo1, __hi1, __lo2, __hi2); } 748 749 /** 750 * @brief Transform string to comparable form. 751 * 752 * This function is a wrapper for strxfrm functionality. It takes the 753 * input string and returns a modified string that can be directly 754 * compared to other transformed strings. In the C locale, this 755 * function just returns a copy of the input string. In some other 756 * locales, it may replace two chars with one, change a char for 757 * another, etc. It does so by returning collate::do_transform(). 758 * 759 * @param __lo Start of string. 760 * @param __hi End of string. 761 * @return Transformed string_type. 762 */ 763 string_type 764 transform(const _CharT* __lo, const _CharT* __hi) const 765 { return this->do_transform(__lo, __hi); } 766 767 /** 768 * @brief Return hash of a string. 769 * 770 * This function computes and returns a hash on the input string. It 771 * does so by returning collate::do_hash(). 772 * 773 * @param __lo Start of string. 774 * @param __hi End of string. 775 * @return Hash value. 776 */ 777 long 778 hash(const _CharT* __lo, const _CharT* __hi) const 779 { return this->do_hash(__lo, __hi); } 780 781 // Used to abstract out _CharT bits in virtual member functions, below. 782 int 783 _M_compare(const _CharT*, const _CharT*) const throw(); 784 785 size_t 786 _M_transform(_CharT*, const _CharT*, size_t) const throw(); 787 788 protected: 789 /// Destructor. 790 virtual 791 ~collate() 792 { _S_destroy_c_locale(_M_c_locale_collate); } 793 794 /** 795 * @brief Compare two strings. 796 * 797 * This function is a hook for derived classes to change the value 798 * returned. @see compare(). 799 * 800 * @param __lo1 Start of string 1. 801 * @param __hi1 End of string 1. 802 * @param __lo2 Start of string 2. 803 * @param __hi2 End of string 2. 804 * @return 1 if string1 > string2, -1 if string1 < string2, else 0. 805 */ 806 virtual int 807 do_compare(const _CharT* __lo1, const _CharT* __hi1, 808 const _CharT* __lo2, const _CharT* __hi2) const; 809 810 /** 811 * @brief Transform string to comparable form. 812 * 813 * This function is a hook for derived classes to change the value 814 * returned. 815 * 816 * @param __lo Start. 817 * @param __hi End. 818 * @return transformed string. 819 */ 820 virtual string_type 821 do_transform(const _CharT* __lo, const _CharT* __hi) const; 822 823 /** 824 * @brief Return hash of a string. 825 * 826 * This function computes and returns a hash on the input string. This 827 * function is a hook for derived classes to change the value returned. 828 * 829 * @param __lo Start of string. 830 * @param __hi End of string. 831 * @return Hash value. 832 */ 833 virtual long 834 do_hash(const _CharT* __lo, const _CharT* __hi) const; 835 }; 836 837 template<typename _CharT> 838 locale::id collate<_CharT>::id; 839 840 // Specializations. 841 template<> 842 int 843 collate<char>::_M_compare(const char*, const char*) const throw(); 844 845 template<> 846 size_t 847 collate<char>::_M_transform(char*, const char*, size_t) const throw(); 848 849 #ifdef _GLIBCXX_USE_WCHAR_T 850 template<> 851 int 852 collate<wchar_t>::_M_compare(const wchar_t*, const wchar_t*) const throw(); 853 854 template<> 855 size_t 856 collate<wchar_t>::_M_transform(wchar_t*, const wchar_t*, size_t) const throw(); 857 #endif 858 859 /// class collate_byname [22.2.4.2]. 860 template<typename _CharT> 861 class _GLIBCXX_NAMESPACE_CXX11 collate_byname : public collate<_CharT> 862 { 863 public: 864 ///@{ 865 /// Public typedefs 866 typedef _CharT char_type; 867 typedef basic_string<_CharT> string_type; 868 ///@} 869 870 explicit 871 collate_byname(const char* __s, size_t __refs = 0) 872 : collate<_CharT>(__refs) 873 { 874 if (__builtin_strcmp(__s, "C") != 0 875 && __builtin_strcmp(__s, "POSIX") != 0) 876 { 877 this->_S_destroy_c_locale(this->_M_c_locale_collate); 878 this->_S_create_c_locale(this->_M_c_locale_collate, __s); 879 } 880 } 881 882 #if __cplusplus >= 201103L 883 explicit 884 collate_byname(const string& __s, size_t __refs = 0) 885 : collate_byname(__s.c_str(), __refs) { } 886 #endif 887 888 protected: 889 virtual 890 ~collate_byname() { } 891 }; 892 893 _GLIBCXX_END_NAMESPACE_VERSION 894 } // namespace 895 896 # include <bits/locale_classes.tcc> 897 898 #endif
