1// Locale support -*- C++ -*-
2
3// Copyright (C) 1997-2024 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#pragma GCC system_header
38
39#include <bits/localefwd.h>
40#include <string>
41#include <ext/atomicity.h>
42
43#ifdef __glibcxx_text_encoding
44#include <text_encoding>
45#endif
46
47namespace std _GLIBCXX_VISIBILITY(default)
48{
49_GLIBCXX_BEGIN_NAMESPACE_VERSION
50
51 // 22.1.1 Class locale
52 /**
53 * @brief Container class for localization functionality.
54 * @ingroup locales
55 *
56 * The locale class is first a class wrapper for C library locales. It is
57 * also an extensible container for user-defined localization. A locale is
58 * a collection of facets that implement various localization features such
59 * as money, time, and number printing.
60 *
61 * Constructing C++ locales does not change the C library locale.
62 *
63 * This library supports efficient construction and copying of locales
64 * through a reference counting implementation of the locale class.
65 */
66 class locale
67 {
68 public:
69 // Types:
70 /// Definition of locale::category.
71 typedef int category;
72
73 // Forward decls and friends:
74 class facet;
75 class id;
76 class _Impl;
77
78 friend class facet;
79 friend class _Impl;
80
81 template<typename _Facet>
82 friend bool
83 has_facet(const locale&) throw();
84
85 template<typename _Facet>
86 friend const _Facet&
87 use_facet(const locale&);
88
89 template<typename _Facet>
90 friend const _Facet*
91 __try_use_facet(const locale&) _GLIBCXX_NOTHROW;
92
93 template<typename _Cache>
94 friend struct __use_cache;
95
96 ///@{
97 /**
98 * @brief Category values.
99 *
100 * The standard category values are none, ctype, numeric, collate, time,
101 * monetary, and messages. They form a bitmask that supports union and
102 * intersection. The category all is the union of these values.
103 *
104 * NB: Order must match _S_facet_categories definition in locale.cc
105 */
106 static const category none = 0;
107 static const category ctype = 1L << 0;
108 static const category numeric = 1L << 1;
109 static const category collate = 1L << 2;
110 static const category time = 1L << 3;
111 static const category monetary = 1L << 4;
112 static const category messages = 1L << 5;
113 static const category all = (ctype | numeric | collate |
114 time | monetary | messages);
115 ///@}
116
117 // Construct/copy/destroy:
118
119 /**
120 * @brief Default constructor.
121 *
122 * Constructs a copy of the global locale. If no locale has been
123 * explicitly set, this is the C locale.
124 */
125 locale() throw();
126
127 /**
128 * @brief Copy constructor.
129 *
130 * Constructs a copy of @a other.
131 *
132 * @param __other The locale to copy.
133 */
134 locale(const locale& __other) throw();
135
136 /**
137 * @brief Named locale constructor.
138 *
139 * Constructs a copy of the named C library locale.
140 *
141 * @param __s Name of the locale to construct.
142 * @throw std::runtime_error if __s is null or an undefined locale.
143 */
144 explicit
145 locale(const char* __s);
146
147 /**
148 * @brief Construct locale with facets from another locale.
149 *
150 * Constructs a copy of the locale @a base. The facets specified by @a
151 * cat are replaced with those from the locale named by @a s. If base is
152 * named, this locale instance will also be named.
153 *
154 * @param __base The locale to copy.
155 * @param __s Name of the locale to use facets from.
156 * @param __cat Set of categories defining the facets to use from __s.
157 * @throw std::runtime_error if __s is null or an undefined locale.
158 */
159 locale(const locale& __base, const char* __s, category __cat);
160
161#if __cplusplus >= 201103L
162 /**
163 * @brief Named locale constructor.
164 *
165 * Constructs a copy of the named C library locale.
166 *
167 * @param __s Name of the locale to construct.
168 * @throw std::runtime_error if __s is an undefined locale.
169 */
170 explicit
171 locale(const std::string& __s) : locale(__s.c_str()) { }
172
173 /**
174 * @brief Construct locale with facets from another locale.
175 *
176 * Constructs a copy of the locale @a base. The facets specified by @a
177 * cat are replaced with those from the locale named by @a s. If base is
178 * named, this locale instance will also be named.
179 *
180 * @param __base The locale to copy.
181 * @param __s Name of the locale to use facets from.
182 * @param __cat Set of categories defining the facets to use from __s.
183 * @throw std::runtime_error if __s is an undefined locale.
184 */
185 locale(const locale& __base, const std::string& __s, category __cat)
186 : locale(__base, __s.c_str(), __cat) { }
187#endif
188
189 /**
190 * @brief Construct locale with facets from another locale.
191 *
192 * Constructs a copy of the locale @a base. The facets specified by @a
193 * cat are replaced with those from the locale @a add. If @a base and @a
194 * add are named, this locale instance will also be named.
195 *
196 * @param __base The locale to copy.
197 * @param __add The locale to use facets from.
198 * @param __cat Set of categories defining the facets to use from add.
199 */
200 locale(const locale& __base, const locale& __add, category __cat);
201
202 /**
203 * @brief Construct locale with another facet.
204 *
205 * Constructs a copy of the locale @a __other. The facet @a __f
206 * is added to @a __other, replacing an existing facet of type
207 * Facet if there is one. If @a __f is null, this locale is a
208 * copy of @a __other.
209 *
210 * @param __other The locale to copy.
211 * @param __f The facet to add in.
212 */
213 template<typename _Facet>
214 locale(const locale& __other, _Facet* __f);
215
216 /// Locale destructor.
217 ~locale() throw();
218
219 /**
220 * @brief Assignment operator.
221 *
222 * Set this locale to be a copy of @a other.
223 *
224 * @param __other The locale to copy.
225 * @return A reference to this locale.
226 */
227 const locale&
228 operator=(const locale& __other) throw();
229
230 /**
231 * @brief Construct locale with another facet.
232 *
233 * Constructs and returns a new copy of this locale. Adds or replaces an
234 * existing facet of type Facet from the locale @a other into the new
235 * locale.
236 *
237 * @tparam _Facet The facet type to copy from other
238 * @param __other The locale to copy from.
239 * @return Newly constructed locale.
240 * @throw std::runtime_error if __other has no facet of type _Facet.
241 */
242 template<typename _Facet>
243 _GLIBCXX_NODISCARD
244 locale
245 combine(const locale& __other) const;
246
247 // Locale operations:
248 /**
249 * @brief Return locale name.
250 * @return Locale name or "*" if unnamed.
251 */
252 _GLIBCXX_NODISCARD _GLIBCXX_DEFAULT_ABI_TAG
253 string
254 name() const;
255
256#ifdef __glibcxx_text_encoding
257# if __CHAR_BIT__ == 8
258 text_encoding
259 encoding() const;
260# else
261 text_encoding
262 encoding() const = delete;
263# endif
264#endif
265
266 /**
267 * @brief Locale equality.
268 *
269 * @param __other The locale to compare against.
270 * @return True if other and this refer to the same locale instance, are
271 * copies, or have the same name. False otherwise.
272 */
273 _GLIBCXX_NODISCARD
274 bool
275 operator==(const locale& __other) const throw();
276
277#if __cpp_impl_three_way_comparison < 201907L
278 /**
279 * @brief Locale inequality.
280 *
281 * @param __other The locale to compare against.
282 * @return ! (*this == __other)
283 */
284 _GLIBCXX_NODISCARD
285 bool
286 operator!=(const locale& __other) const throw()
287 { return !(this->operator==(__other)); }
288#endif
289
290 /**
291 * @brief Compare two strings according to collate.
292 *
293 * Template operator to compare two strings using the compare function of
294 * the collate facet in this locale. One use is to provide the locale to
295 * the sort function. For example, a vector v of strings could be sorted
296 * according to locale loc by doing:
297 * @code
298 * std::sort(v.begin(), v.end(), loc);
299 * @endcode
300 *
301 * @param __s1 First string to compare.
302 * @param __s2 Second string to compare.
303 * @return True if collate<_Char> facet compares __s1 < __s2, else false.
304 */
305 template<typename _Char, typename _Traits, typename _Alloc>
306 _GLIBCXX_NODISCARD
307 bool
308 operator()(const basic_string<_Char, _Traits, _Alloc>& __s1,
309 const basic_string<_Char, _Traits, _Alloc>& __s2) const;
310
311 // Global locale objects:
312 /**
313 * @brief Set global locale
314 *
315 * This function sets the global locale to the argument and returns a
316 * copy of the previous global locale. If the argument has a name, it
317 * will also call std::setlocale(LC_ALL, loc.name()).
318 *
319 * @param __loc The new locale to make global.
320 * @return Copy of the old global locale.
321 */
322 static locale
323 global(const locale& __loc);
324
325 /**
326 * @brief Return reference to the C locale.
327 */
328 _GLIBCXX_NODISCARD
329 static const locale&
330 classic();
331
332 private:
333 // The (shared) implementation
334 _Impl* _M_impl;
335
336 // The "C" reference locale
337 static _Impl* _S_classic;
338
339 // Current global locale
340 static _Impl* _S_global;
341
342 // Names of underlying locale categories.
343 // NB: locale::global() has to know how to modify all the
344 // underlying categories, not just the ones required by the C++
345 // standard.
346 static const char* const* const _S_categories;
347
348 // Number of standard categories. For C++, these categories are
349 // collate, ctype, monetary, numeric, time, and messages. These
350 // directly correspond to ISO C99 macros LC_COLLATE, LC_CTYPE,
351 // LC_MONETARY, LC_NUMERIC, and LC_TIME. In addition, POSIX (IEEE
352 // 1003.1-2001) specifies LC_MESSAGES.
353 // In addition to the standard categories, the underlying
354 // operating system is allowed to define extra LC_*
355 // macros. For GNU systems, the following are also valid:
356 // LC_PAPER, LC_NAME, LC_ADDRESS, LC_TELEPHONE, LC_MEASUREMENT,
357 // and LC_IDENTIFICATION.
358 enum { _S_categories_size = 6 + _GLIBCXX_NUM_CATEGORIES };
359
360#ifdef __GTHREADS
361 static __gthread_once_t _S_once;
362#endif
363
364 explicit
365 locale(_Impl*) throw();
366
367 static void
368 _S_initialize();
369
370 static void
371 _S_initialize_once() throw();
372
373 static category
374 _S_normalize_category(category);
375
376 void
377 _M_coalesce(const locale& __base, const locale& __add, category __cat);
378
379#if _GLIBCXX_USE_CXX11_ABI
380 static const id* const _S_twinned_facets[];
381#endif
382 };
383
384
385 // 22.1.1.1.2 Class locale::facet
386 /**
387 * @brief Localization functionality base class.
388 * @ingroup locales
389 *
390 * The facet class is the base class for a localization feature, such as
391 * money, time, and number printing. It provides common support for facets
392 * and reference management.
393 *
394 * Facets may not be copied or assigned.
395 */
396 class locale::facet
397 {
398 private:
399 friend class locale;
400 friend class locale::_Impl;
401
402 mutable _Atomic_word _M_refcount;
403
404 // Contains data from the underlying "C" library for the classic locale.
405 static __c_locale _S_c_locale;
406
407 // String literal for the name of the classic locale.
408 static const char _S_c_name[2];
409
410#ifdef __GTHREADS
411 static __gthread_once_t _S_once;
412#endif
413
414 static void
415 _S_initialize_once();
416
417 protected:
418 /**
419 * @brief Facet constructor.
420 *
421 * This is the constructor provided by the standard. If refs is 0, the
422 * facet is destroyed when the last referencing locale is destroyed.
423 * Otherwise the facet will never be destroyed.
424 *
425 * @param __refs The initial value for reference count.
426 */
427 explicit
428 facet(size_t __refs = 0) throw() : _M_refcount(__refs ? 1 : 0)
429 { }
430
431 /// Facet destructor.
432 virtual
433 ~facet();
434
435 static void
436 _S_create_c_locale(__c_locale& __cloc, const char* __s,
437 __c_locale __old = 0);
438
439 static __c_locale
440 _S_clone_c_locale(__c_locale& __cloc) throw();
441
442 static void
443 _S_destroy_c_locale(__c_locale& __cloc);
444
445 static __c_locale
446 _S_lc_ctype_c_locale(__c_locale __cloc, const char* __s);
447
448 // Returns data from the underlying "C" library data for the
449 // classic locale.
450 static __c_locale
451 _S_get_c_locale();
452
453 _GLIBCXX_CONST static const char*
454 _S_get_c_name() throw();
455
456#if __cplusplus < 201103L
457 private:
458 facet(const facet&); // Not defined.
459
460 facet&
461 operator=(const facet&); // Not defined.
462#else
463 facet(const facet&) = delete;
464
465 facet&
466 operator=(const facet&) = delete;
467#endif
468
469 private:
470 void
471 _M_add_reference() const throw()
472 { __gnu_cxx::__atomic_add_dispatch(mem: &_M_refcount, val: 1); }
473
474 void
475 _M_remove_reference() const throw()
476 {
477 // Be race-detector-friendly. For more info see bits/c++config.
478 _GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_M_refcount);
479 if (__gnu_cxx::__exchange_and_add_dispatch(mem: &_M_refcount, val: -1) == 1)
480 {
481 _GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_M_refcount);
482 __try
483 { delete this; }
484 __catch(...)
485 { }
486 }
487 }
488
489 const facet* _M_sso_shim(const id*) const;
490 const facet* _M_cow_shim(const id*) const;
491
492 protected:
493 class __shim; // For internal use only.
494 };
495
496
497 // 22.1.1.1.3 Class locale::id
498 /**
499 * @brief Facet ID class.
500 * @ingroup locales
501 *
502 * The ID class provides facets with an index used to identify them.
503 * Every facet class must define a public static member locale::id, or be
504 * derived from a facet that provides this member, otherwise the facet
505 * cannot be used in a locale. The locale::id ensures that each class
506 * type gets a unique identifier.
507 */
508 class locale::id
509 {
510 private:
511 friend class locale;
512 friend class locale::_Impl;
513
514 template<typename _Facet>
515 friend const _Facet&
516 use_facet(const locale&);
517
518 template<typename _Facet>
519 friend bool
520 has_facet(const locale&) throw();
521
522 template<typename _Facet>
523 friend const _Facet*
524 __try_use_facet(const locale&) _GLIBCXX_NOTHROW;
525
526 // NB: There is no accessor for _M_index because it may be used
527 // before the constructor is run; the effect of calling a member
528 // function (even an inline) would be undefined.
529 mutable size_t _M_index;
530
531 // Last id number assigned.
532 static _Atomic_word _S_refcount;
533
534 void
535 operator=(const id&); // Not defined.
536
537 id(const id&); // Not defined.
538
539 public:
540 // NB: This class is always a static data member, and thus can be
541 // counted on to be zero-initialized.
542 /// Constructor.
543 id() { }
544
545 size_t
546 _M_id() const throw();
547 };
548
549
550 // Implementation object for locale.
551 class locale::_Impl
552 {
553 public:
554 // Friends.
555 friend class locale;
556 friend class locale::facet;
557
558 template<typename _Facet>
559 friend bool
560 has_facet(const locale&) throw();
561
562 template<typename _Facet>
563 friend const _Facet&
564 use_facet(const locale&);
565
566 template<typename _Facet>
567 friend const _Facet*
568 __try_use_facet(const locale&) _GLIBCXX_NOTHROW;
569
570 template<typename _Cache>
571 friend struct __use_cache;
572
573 private:
574 // Data Members.
575 _Atomic_word _M_refcount;
576 const facet** _M_facets;
577 size_t _M_facets_size;
578 const facet** _M_caches;
579 char** _M_names;
580 static const locale::id* const _S_id_ctype[];
581 static const locale::id* const _S_id_numeric[];
582 static const locale::id* const _S_id_collate[];
583 static const locale::id* const _S_id_time[];
584 static const locale::id* const _S_id_monetary[];
585 static const locale::id* const _S_id_messages[];
586 static const locale::id* const* const _S_facet_categories[];
587
588 void
589 _M_add_reference() throw()
590 { __gnu_cxx::__atomic_add_dispatch(mem: &_M_refcount, val: 1); }
591
592 void
593 _M_remove_reference() throw()
594 {
595 // Be race-detector-friendly. For more info see bits/c++config.
596 _GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_M_refcount);
597 if (__gnu_cxx::__exchange_and_add_dispatch(mem: &_M_refcount, val: -1) == 1)
598 {
599 _GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_M_refcount);
600 __try
601 { delete this; }
602 __catch(...)
603 { }
604 }
605 }
606
607 _Impl(const _Impl&, size_t);
608 _Impl(const char*, size_t);
609 _Impl(size_t) throw();
610
611 ~_Impl() throw();
612
613 _Impl(const _Impl&); // Not defined.
614
615 void
616 operator=(const _Impl&); // Not defined.
617
618 bool
619 _M_check_same_name()
620 {
621 bool __ret = true;
622 if (_M_names[1])
623 // We must actually compare all the _M_names: can be all equal!
624 for (size_t __i = 0; __ret && __i < _S_categories_size - 1; ++__i)
625 __ret = __builtin_strcmp(_M_names[__i], _M_names[__i + 1]) == 0;
626 return __ret;
627 }
628
629 void
630 _M_replace_categories(const _Impl*, category);
631
632 void
633 _M_replace_category(const _Impl*, const locale::id* const*);
634
635 void
636 _M_replace_facet(const _Impl*, const locale::id*);
637
638 void
639 _M_install_facet(const locale::id*, const facet*);
640
641 template<typename _Facet>
642 void
643 _M_init_facet(_Facet* __facet)
644 { _M_install_facet(&_Facet::id, __facet); }
645
646 template<typename _Facet>
647 void
648 _M_init_facet_unchecked(_Facet* __facet)
649 {
650 __facet->_M_add_reference();
651 _M_facets[_Facet::id._M_id()] = __facet;
652 }
653
654 void
655 _M_install_cache(const facet*, size_t);
656
657 void _M_init_extra(facet**);
658 void _M_init_extra(void*, void*, const char*, const char*);
659
660#ifdef _GLIBCXX_LONG_DOUBLE_ALT128_COMPAT
661 void _M_init_extra_ldbl128(bool);
662#endif
663 };
664
665
666 /**
667 * @brief Facet for localized string comparison.
668 *
669 * This facet encapsulates the code to compare strings in a localized
670 * manner.
671 *
672 * The collate template uses protected virtual functions to provide
673 * the actual results. The public accessors forward the call to
674 * the virtual functions. These virtual functions are hooks for
675 * developers to implement the behavior they require from the
676 * collate facet.
677 */
678 template<typename _CharT>
679 class _GLIBCXX_NAMESPACE_CXX11 collate : public locale::facet
680 {
681 public:
682 // Types:
683 ///@{
684 /// Public typedefs
685 typedef _CharT char_type;
686 typedef basic_string<_CharT> string_type;
687 ///@}
688
689 protected:
690 // Underlying "C" library locale information saved from
691 // initialization, needed by collate_byname as well.
692 __c_locale _M_c_locale_collate;
693
694 public:
695 /// Numpunct facet id.
696 static locale::id id;
697
698 /**
699 * @brief Constructor performs initialization.
700 *
701 * This is the constructor provided by the standard.
702 *
703 * @param __refs Passed to the base facet class.
704 */
705 explicit
706 collate(size_t __refs = 0)
707 : facet(__refs), _M_c_locale_collate(_S_get_c_locale())
708 { }
709
710 /**
711 * @brief Internal constructor. Not for general use.
712 *
713 * This is a constructor for use by the library itself to set up new
714 * locales.
715 *
716 * @param __cloc The C locale.
717 * @param __refs Passed to the base facet class.
718 */
719 explicit
720 collate(__c_locale __cloc, size_t __refs = 0)
721 : facet(__refs), _M_c_locale_collate(_S_clone_c_locale(__cloc))
722 { }
723
724 /**
725 * @brief Compare two strings.
726 *
727 * This function compares two strings and returns the result by calling
728 * collate::do_compare().
729 *
730 * @param __lo1 Start of string 1.
731 * @param __hi1 End of string 1.
732 * @param __lo2 Start of string 2.
733 * @param __hi2 End of string 2.
734 * @return 1 if string1 > string2, -1 if string1 < string2, else 0.
735 */
736 int
737 compare(const _CharT* __lo1, const _CharT* __hi1,
738 const _CharT* __lo2, const _CharT* __hi2) const
739 { return this->do_compare(__lo1, __hi1, __lo2, __hi2); }
740
741 /**
742 * @brief Transform string to comparable form.
743 *
744 * This function is a wrapper for strxfrm functionality. It takes the
745 * input string and returns a modified string that can be directly
746 * compared to other transformed strings. In the C locale, this
747 * function just returns a copy of the input string. In some other
748 * locales, it may replace two chars with one, change a char for
749 * another, etc. It does so by returning collate::do_transform().
750 *
751 * @param __lo Start of string.
752 * @param __hi End of string.
753 * @return Transformed string_type.
754 */
755 string_type
756 transform(const _CharT* __lo, const _CharT* __hi) const
757 { return this->do_transform(__lo, __hi); }
758
759 /**
760 * @brief Return hash of a string.
761 *
762 * This function computes and returns a hash on the input string. It
763 * does so by returning collate::do_hash().
764 *
765 * @param __lo Start of string.
766 * @param __hi End of string.
767 * @return Hash value.
768 */
769 long
770 hash(const _CharT* __lo, const _CharT* __hi) const
771 { return this->do_hash(__lo, __hi); }
772
773 // Used to abstract out _CharT bits in virtual member functions, below.
774 int
775 _M_compare(const _CharT*, const _CharT*) const throw();
776
777 size_t
778 _M_transform(_CharT*, const _CharT*, size_t) const throw();
779
780 protected:
781 /// Destructor.
782 virtual
783 ~collate()
784 { _S_destroy_c_locale(cloc&: _M_c_locale_collate); }
785
786 /**
787 * @brief Compare two strings.
788 *
789 * This function is a hook for derived classes to change the value
790 * returned. @see compare().
791 *
792 * @param __lo1 Start of string 1.
793 * @param __hi1 End of string 1.
794 * @param __lo2 Start of string 2.
795 * @param __hi2 End of string 2.
796 * @return 1 if string1 > string2, -1 if string1 < string2, else 0.
797 */
798 virtual int
799 do_compare(const _CharT* __lo1, const _CharT* __hi1,
800 const _CharT* __lo2, const _CharT* __hi2) const;
801
802 /**
803 * @brief Transform string to comparable form.
804 *
805 * This function is a hook for derived classes to change the value
806 * returned.
807 *
808 * @param __lo Start.
809 * @param __hi End.
810 * @return transformed string.
811 */
812 virtual string_type
813 do_transform(const _CharT* __lo, const _CharT* __hi) const;
814
815 /**
816 * @brief Return hash of a string.
817 *
818 * This function computes and returns a hash on the input string. This
819 * function is a hook for derived classes to change the value returned.
820 *
821 * @param __lo Start of string.
822 * @param __hi End of string.
823 * @return Hash value.
824 */
825 virtual long
826 do_hash(const _CharT* __lo, const _CharT* __hi) const;
827 };
828
829 template<typename _CharT>
830 locale::id collate<_CharT>::id;
831
832 // Specializations.
833 template<>
834 int
835 collate<char>::_M_compare(const char*, const char*) const throw();
836
837 template<>
838 size_t
839 collate<char>::_M_transform(char*, const char*, size_t) const throw();
840
841#ifdef _GLIBCXX_USE_WCHAR_T
842 template<>
843 int
844 collate<wchar_t>::_M_compare(const wchar_t*, const wchar_t*) const throw();
845
846 template<>
847 size_t
848 collate<wchar_t>::_M_transform(wchar_t*, const wchar_t*, size_t) const throw();
849#endif
850
851 /// class collate_byname [22.2.4.2].
852 template<typename _CharT>
853 class _GLIBCXX_NAMESPACE_CXX11 collate_byname : public collate<_CharT>
854 {
855 public:
856 ///@{
857 /// Public typedefs
858 typedef _CharT char_type;
859 typedef basic_string<_CharT> string_type;
860 ///@}
861
862 explicit
863 collate_byname(const char* __s, size_t __refs = 0)
864 : collate<_CharT>(__refs)
865 {
866 if (__builtin_strcmp(__s, "C") != 0
867 && __builtin_strcmp(__s, "POSIX") != 0)
868 {
869 this->_S_destroy_c_locale(this->_M_c_locale_collate);
870 this->_S_create_c_locale(this->_M_c_locale_collate, __s);
871 }
872 }
873
874#if __cplusplus >= 201103L
875 explicit
876 collate_byname(const string& __s, size_t __refs = 0)
877 : collate_byname(__s.c_str(), __refs) { }
878#endif
879
880 protected:
881 virtual
882 ~collate_byname() { }
883 };
884
885_GLIBCXX_END_NAMESPACE_VERSION
886} // namespace
887
888# include <bits/locale_classes.tcc>
889
890#endif
891