1 // Locale support -*- C++ -*-
2
3 // Copyright (C) 1997-2021 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
_GLIBCXX_VISIBILITY(default)43 namespace std _GLIBCXX_VISIBILITY(default)
44 {
45 _GLIBCXX_BEGIN_NAMESPACE_VERSION
46
47 // 22.1.1 Class locale
48 /**
49 * @brief Container class for localization functionality.
50 * @ingroup locales
51 *
52 * The locale class is first a class wrapper for C library locales. It is
53 * also an extensible container for user-defined localization. A locale is
54 * a collection of facets that implement various localization features such
55 * as money, time, and number printing.
56 *
57 * Constructing C++ locales does not change the C library locale.
58 *
59 * This library supports efficient construction and copying of locales
60 * through a reference counting implementation of the locale class.
61 */
62 class locale
63 {
64 public:
65 // Types:
66 /// Definition of locale::category.
67 typedef int category;
68
69 // Forward decls and friends:
70 class facet;
71 class id;
72 class _Impl;
73
74 friend class facet;
75 friend class _Impl;
76
77 template<typename _Facet>
78 friend bool
79 has_facet(const locale&) throw();
80
81 template<typename _Facet>
82 friend const _Facet&
83 use_facet(const locale&);
84
85 template<typename _Cache>
86 friend struct __use_cache;
87
88 ///@{
89 /**
90 * @brief Category values.
91 *
92 * The standard category values are none, ctype, numeric, collate, time,
93 * monetary, and messages. They form a bitmask that supports union and
94 * intersection. The category all is the union of these values.
95 *
96 * NB: Order must match _S_facet_categories definition in locale.cc
97 */
98 static const category none = 0;
99 static const category ctype = 1L << 0;
100 static const category numeric = 1L << 1;
101 static const category collate = 1L << 2;
102 static const category time = 1L << 3;
103 static const category monetary = 1L << 4;
104 static const category messages = 1L << 5;
105 static const category all = (ctype | numeric | collate |
106 time | monetary | messages);
107 ///@}
108
109 // Construct/copy/destroy:
110
111 /**
112 * @brief Default constructor.
113 *
114 * Constructs a copy of the global locale. If no locale has been
115 * explicitly set, this is the C locale.
116 */
117 locale() throw();
118
119 /**
120 * @brief Copy constructor.
121 *
122 * Constructs a copy of @a other.
123 *
124 * @param __other The locale to copy.
125 */
126 locale(const locale& __other) throw();
127
128 /**
129 * @brief Named locale constructor.
130 *
131 * Constructs a copy of the named C library locale.
132 *
133 * @param __s Name of the locale to construct.
134 * @throw std::runtime_error if __s is null or an undefined locale.
135 */
136 explicit
137 locale(const char* __s);
138
139 /**
140 * @brief Construct locale with facets from another locale.
141 *
142 * Constructs a copy of the locale @a base. The facets specified by @a
143 * cat are replaced with those from the locale named by @a s. If base is
144 * named, this locale instance will also be named.
145 *
146 * @param __base The locale to copy.
147 * @param __s Name of the locale to use facets from.
148 * @param __cat Set of categories defining the facets to use from __s.
149 * @throw std::runtime_error if __s is null or an undefined locale.
150 */
151 locale(const locale& __base, const char* __s, category __cat);
152
153 #if __cplusplus >= 201103L
154 /**
155 * @brief Named locale constructor.
156 *
157 * Constructs a copy of the named C library locale.
158 *
159 * @param __s Name of the locale to construct.
160 * @throw std::runtime_error if __s is an undefined locale.
161 */
162 explicit
163 locale(const std::string& __s) : locale(__s.c_str()) { }
164
165 /**
166 * @brief Construct locale with facets from another locale.
167 *
168 * Constructs a copy of the locale @a base. The facets specified by @a
169 * cat are replaced with those from the locale named by @a s. If base is
170 * named, this locale instance will also be named.
171 *
172 * @param __base The locale to copy.
173 * @param __s Name of the locale to use facets from.
174 * @param __cat Set of categories defining the facets to use from __s.
175 * @throw std::runtime_error if __s is an undefined locale.
176 */
177 locale(const locale& __base, const std::string& __s, category __cat)
178 : locale(__base, __s.c_str(), __cat) { }
179 #endif
180
181 /**
182 * @brief Construct locale with facets from another locale.
183 *
184 * Constructs a copy of the locale @a base. The facets specified by @a
185 * cat are replaced with those from the locale @a add. If @a base and @a
186 * add are named, this locale instance will also be named.
187 *
188 * @param __base The locale to copy.
189 * @param __add The locale to use facets from.
190 * @param __cat Set of categories defining the facets to use from add.
191 */
192 locale(const locale& __base, const locale& __add, category __cat);
193
194 /**
195 * @brief Construct locale with another facet.
196 *
197 * Constructs a copy of the locale @a __other. The facet @a __f
198 * is added to @a __other, replacing an existing facet of type
199 * Facet if there is one. If @a __f is null, this locale is a
200 * copy of @a __other.
201 *
202 * @param __other The locale to copy.
203 * @param __f The facet to add in.
204 */
205 template<typename _Facet>
206 locale(const locale& __other, _Facet* __f);
207
208 /// Locale destructor.
209 ~locale() throw();
210
211 /**
212 * @brief Assignment operator.
213 *
214 * Set this locale to be a copy of @a other.
215 *
216 * @param __other The locale to copy.
217 * @return A reference to this locale.
218 */
219 const locale&
220 operator=(const locale& __other) throw();
221
222 /**
223 * @brief Construct locale with another facet.
224 *
225 * Constructs and returns a new copy of this locale. Adds or replaces an
226 * existing facet of type Facet from the locale @a other into the new
227 * locale.
228 *
229 * @tparam _Facet The facet type to copy from other
230 * @param __other The locale to copy from.
231 * @return Newly constructed locale.
232 * @throw std::runtime_error if __other has no facet of type _Facet.
233 */
234 template<typename _Facet>
235 locale
236 combine(const locale& __other) const;
237
238 // Locale operations:
239 /**
240 * @brief Return locale name.
241 * @return Locale name or "*" if unnamed.
242 */
243 _GLIBCXX_DEFAULT_ABI_TAG
244 string
245 name() const;
246
247 /**
248 * @brief Locale equality.
249 *
250 * @param __other The locale to compare against.
251 * @return True if other and this refer to the same locale instance, are
252 * copies, or have the same name. False otherwise.
253 */
254 bool
255 operator==(const locale& __other) const throw();
256
257 #if __cpp_impl_three_way_comparison < 201907L
258 /**
259 * @brief Locale inequality.
260 *
261 * @param __other The locale to compare against.
262 * @return ! (*this == __other)
263 */
264 bool
265 operator!=(const locale& __other) const throw()
266 { return !(this->operator==(__other)); }
267 #endif
268
269 /**
270 * @brief Compare two strings according to collate.
271 *
272 * Template operator to compare two strings using the compare function of
273 * the collate facet in this locale. One use is to provide the locale to
274 * the sort function. For example, a vector v of strings could be sorted
275 * according to locale loc by doing:
276 * @code
277 * std::sort(v.begin(), v.end(), loc);
278 * @endcode
279 *
280 * @param __s1 First string to compare.
281 * @param __s2 Second string to compare.
282 * @return True if collate<_Char> facet compares __s1 < __s2, else false.
283 */
284 template<typename _Char, typename _Traits, typename _Alloc>
285 bool
286 operator()(const basic_string<_Char, _Traits, _Alloc>& __s1,
287 const basic_string<_Char, _Traits, _Alloc>& __s2) const;
288
289 // Global locale objects:
290 /**
291 * @brief Set global locale
292 *
293 * This function sets the global locale to the argument and returns a
294 * copy of the previous global locale. If the argument has a name, it
295 * will also call std::setlocale(LC_ALL, loc.name()).
296 *
297 * @param __loc The new locale to make global.
298 * @return Copy of the old global locale.
299 */
300 static locale
301 global(const locale& __loc);
302
303 /**
304 * @brief Return reference to the C locale.
305 */
306 static const locale&
307 classic();
308
309 private:
310 // The (shared) implementation
311 _Impl* _M_impl;
312
313 // The "C" reference locale
314 static _Impl* _S_classic;
315
316 // Current global locale
317 static _Impl* _S_global;
318
319 // Names of underlying locale categories.
320 // NB: locale::global() has to know how to modify all the
321 // underlying categories, not just the ones required by the C++
322 // standard.
323 static const char* const* const _S_categories;
324
325 // Number of standard categories. For C++, these categories are
326 // collate, ctype, monetary, numeric, time, and messages. These
327 // directly correspond to ISO C99 macros LC_COLLATE, LC_CTYPE,
328 // LC_MONETARY, LC_NUMERIC, and LC_TIME. In addition, POSIX (IEEE
329 // 1003.1-2001) specifies LC_MESSAGES.
330 // In addition to the standard categories, the underlying
331 // operating system is allowed to define extra LC_*
332 // macros. For GNU systems, the following are also valid:
333 // LC_PAPER, LC_NAME, LC_ADDRESS, LC_TELEPHONE, LC_MEASUREMENT,
334 // and LC_IDENTIFICATION.
335 enum { _S_categories_size = 6 + _GLIBCXX_NUM_CATEGORIES };
336
337 #ifdef __GTHREADS
338 static __gthread_once_t _S_once;
339 #endif
340
341 explicit
342 locale(_Impl*) throw();
343
344 static void
345 _S_initialize();
346
347 static void
348 _S_initialize_once() throw();
349
350 static category
351 _S_normalize_category(category);
352
353 void
354 _M_coalesce(const locale& __base, const locale& __add, category __cat);
355
356 #if _GLIBCXX_USE_CXX11_ABI
357 static const id* const _S_twinned_facets[];
358 #endif
359 };
360
361
362 // 22.1.1.1.2 Class locale::facet
363 /**
364 * @brief Localization functionality base class.
365 * @ingroup locales
366 *
367 * The facet class is the base class for a localization feature, such as
368 * money, time, and number printing. It provides common support for facets
369 * and reference management.
370 *
371 * Facets may not be copied or assigned.
372 */
373 class locale::facet
374 {
375 private:
376 friend class locale;
377 friend class locale::_Impl;
378
379 mutable _Atomic_word _M_refcount;
380
381 // Contains data from the underlying "C" library for the classic locale.
382 static __c_locale _S_c_locale;
383
384 // String literal for the name of the classic locale.
385 static const char _S_c_name[2];
386
387 #ifdef __GTHREADS
388 static __gthread_once_t _S_once;
389 #endif
390
391 static void
392 _S_initialize_once();
393
394 protected:
395 /**
396 * @brief Facet constructor.
397 *
398 * This is the constructor provided by the standard. If refs is 0, the
399 * facet is destroyed when the last referencing locale is destroyed.
400 * Otherwise the facet will never be destroyed.
401 *
402 * @param __refs The initial value for reference count.
403 */
404 explicit
405 facet(size_t __refs = 0) throw() : _M_refcount(__refs ? 1 : 0)
406 { }
407
408 /// Facet destructor.
409 virtual
410 ~facet();
411
412 static void
413 _S_create_c_locale(__c_locale& __cloc, const char* __s,
414 __c_locale __old = 0);
415
416 static __c_locale
417 _S_clone_c_locale(__c_locale& __cloc) throw();
418
419 static void
420 _S_destroy_c_locale(__c_locale& __cloc);
421
422 static __c_locale
423 _S_lc_ctype_c_locale(__c_locale __cloc, const char* __s);
424
425 // Returns data from the underlying "C" library data for the
426 // classic locale.
427 static __c_locale
428 _S_get_c_locale();
429
430 _GLIBCXX_CONST static const char*
431 _S_get_c_name() throw();
432
433 #if __cplusplus < 201103L
434 private:
435 facet(const facet&); // Not defined.
436
437 facet&
438 operator=(const facet&); // Not defined.
439 #else
440 facet(const facet&) = delete;
441
442 facet&
443 operator=(const facet&) = delete;
444 #endif
445
446 private:
447 void
448 _M_add_reference() const throw()
449 { __gnu_cxx::__atomic_add_dispatch(&_M_refcount, 1); }
450
451 void
452 _M_remove_reference() const throw()
453 {
454 // Be race-detector-friendly. For more info see bits/c++config.
455 _GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_M_refcount);
456 if (__gnu_cxx::__exchange_and_add_dispatch(&_M_refcount, -1) == 1)
457 {
458 _GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_M_refcount);
459 __try
460 { delete this; }
461 __catch(...)
462 { }
463 }
464 }
465
466 const facet* _M_sso_shim(const id*) const;
467 const facet* _M_cow_shim(const id*) const;
468
469 protected:
470 class __shim; // For internal use only.
471 };
472
473
474 // 22.1.1.1.3 Class locale::id
475 /**
476 * @brief Facet ID class.
477 * @ingroup locales
478 *
479 * The ID class provides facets with an index used to identify them.
480 * Every facet class must define a public static member locale::id, or be
481 * derived from a facet that provides this member, otherwise the facet
482 * cannot be used in a locale. The locale::id ensures that each class
483 * type gets a unique identifier.
484 */
485 class locale::id
486 {
487 private:
488 friend class locale;
489 friend class locale::_Impl;
490
491 template<typename _Facet>
492 friend const _Facet&
493 use_facet(const locale&);
494
495 template<typename _Facet>
496 friend bool
497 has_facet(const locale&) throw();
498
499 // NB: There is no accessor for _M_index because it may be used
500 // before the constructor is run; the effect of calling a member
501 // function (even an inline) would be undefined.
502 mutable size_t _M_index;
503
504 // Last id number assigned.
505 static _Atomic_word _S_refcount;
506
507 void
508 operator=(const id&); // Not defined.
509
510 id(const id&); // Not defined.
511
512 public:
513 // NB: This class is always a static data member, and thus can be
514 // counted on to be zero-initialized.
515 /// Constructor.
516 id() { }
517
518 size_t
519 _M_id() const throw();
520 };
521
522
523 // Implementation object for locale.
524 class locale::_Impl
525 {
526 public:
527 // Friends.
528 friend class locale;
529 friend class locale::facet;
530
531 template<typename _Facet>
532 friend bool
533 has_facet(const locale&) throw();
534
535 template<typename _Facet>
536 friend const _Facet&
537 use_facet(const locale&);
538
539 template<typename _Cache>
540 friend struct __use_cache;
541
542 private:
543 // Data Members.
544 _Atomic_word _M_refcount;
545 const facet** _M_facets;
546 size_t _M_facets_size;
547 const facet** _M_caches;
548 char** _M_names;
549 static const locale::id* const _S_id_ctype[];
550 static const locale::id* const _S_id_numeric[];
551 static const locale::id* const _S_id_collate[];
552 static const locale::id* const _S_id_time[];
553 static const locale::id* const _S_id_monetary[];
554 static const locale::id* const _S_id_messages[];
555 static const locale::id* const* const _S_facet_categories[];
556
557 void
558 _M_add_reference() throw()
559 { __gnu_cxx::__atomic_add_dispatch(&_M_refcount, 1); }
560
561 void
562 _M_remove_reference() throw()
563 {
564 // Be race-detector-friendly. For more info see bits/c++config.
565 _GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_M_refcount);
566 if (__gnu_cxx::__exchange_and_add_dispatch(&_M_refcount, -1) == 1)
567 {
568 _GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_M_refcount);
569 __try
570 { delete this; }
571 __catch(...)
572 { }
573 }
574 }
575
576 _Impl(const _Impl&, size_t);
577 _Impl(const char*, size_t);
578 _Impl(size_t) throw();
579
580 ~_Impl() throw();
581
582 _Impl(const _Impl&); // Not defined.
583
584 void
585 operator=(const _Impl&); // Not defined.
586
587 bool
588 _M_check_same_name()
589 {
590 bool __ret = true;
591 if (_M_names[1])
592 // We must actually compare all the _M_names: can be all equal!
593 for (size_t __i = 0; __ret && __i < _S_categories_size - 1; ++__i)
594 __ret = __builtin_strcmp(_M_names[__i], _M_names[__i + 1]) == 0;
595 return __ret;
596 }
597
598 void
599 _M_replace_categories(const _Impl*, category);
600
601 void
602 _M_replace_category(const _Impl*, const locale::id* const*);
603
604 void
605 _M_replace_facet(const _Impl*, const locale::id*);
606
607 void
608 _M_install_facet(const locale::id*, const facet*);
609
610 template<typename _Facet>
611 void
612 _M_init_facet(_Facet* __facet)
613 { _M_install_facet(&_Facet::id, __facet); }
614
615 template<typename _Facet>
616 void
617 _M_init_facet_unchecked(_Facet* __facet)
618 {
619 __facet->_M_add_reference();
620 _M_facets[_Facet::id._M_id()] = __facet;
621 }
622
623 void
624 _M_install_cache(const facet*, size_t);
625
626 void _M_init_extra(facet**);
627 void _M_init_extra(void*, void*, const char*, const char*);
628
629 #ifdef _GLIBCXX_LONG_DOUBLE_ALT128_COMPAT
630 void _M_init_extra_ldbl128(bool);
631 #endif
632 };
633
634
635 /**
636 * @brief Facet for localized string comparison.
637 *
638 * This facet encapsulates the code to compare strings in a localized
639 * manner.
640 *
641 * The collate template uses protected virtual functions to provide
642 * the actual results. The public accessors forward the call to
643 * the virtual functions. These virtual functions are hooks for
644 * developers to implement the behavior they require from the
645 * collate facet.
646 */
647 template<typename _CharT>
648 class _GLIBCXX_NAMESPACE_CXX11 collate : public locale::facet
649 {
650 public:
651 // Types:
652 ///@{
653 /// Public typedefs
654 typedef _CharT char_type;
655 typedef basic_string<_CharT> string_type;
656 ///@}
657
658 protected:
659 // Underlying "C" library locale information saved from
660 // initialization, needed by collate_byname as well.
661 __c_locale _M_c_locale_collate;
662
663 public:
664 /// Numpunct facet id.
665 static locale::id id;
666
667 /**
668 * @brief Constructor performs initialization.
669 *
670 * This is the constructor provided by the standard.
671 *
672 * @param __refs Passed to the base facet class.
673 */
674 explicit
675 collate(size_t __refs = 0)
676 : facet(__refs), _M_c_locale_collate(_S_get_c_locale())
677 { }
678
679 /**
680 * @brief Internal constructor. Not for general use.
681 *
682 * This is a constructor for use by the library itself to set up new
683 * locales.
684 *
685 * @param __cloc The C locale.
686 * @param __refs Passed to the base facet class.
687 */
688 explicit
689 collate(__c_locale __cloc, size_t __refs = 0)
690 : facet(__refs), _M_c_locale_collate(_S_clone_c_locale(__cloc))
691 { }
692
693 /**
694 * @brief Compare two strings.
695 *
696 * This function compares two strings and returns the result by calling
697 * collate::do_compare().
698 *
699 * @param __lo1 Start of string 1.
700 * @param __hi1 End of string 1.
701 * @param __lo2 Start of string 2.
702 * @param __hi2 End of string 2.
703 * @return 1 if string1 > string2, -1 if string1 < string2, else 0.
704 */
705 int
706 compare(const _CharT* __lo1, const _CharT* __hi1,
707 const _CharT* __lo2, const _CharT* __hi2) const
708 { return this->do_compare(__lo1, __hi1, __lo2, __hi2); }
709
710 /**
711 * @brief Transform string to comparable form.
712 *
713 * This function is a wrapper for strxfrm functionality. It takes the
714 * input string and returns a modified string that can be directly
715 * compared to other transformed strings. In the C locale, this
716 * function just returns a copy of the input string. In some other
717 * locales, it may replace two chars with one, change a char for
718 * another, etc. It does so by returning collate::do_transform().
719 *
720 * @param __lo Start of string.
721 * @param __hi End of string.
722 * @return Transformed string_type.
723 */
724 string_type
725 transform(const _CharT* __lo, const _CharT* __hi) const
726 { return this->do_transform(__lo, __hi); }
727
728 /**
729 * @brief Return hash of a string.
730 *
731 * This function computes and returns a hash on the input string. It
732 * does so by returning collate::do_hash().
733 *
734 * @param __lo Start of string.
735 * @param __hi End of string.
736 * @return Hash value.
737 */
738 long
739 hash(const _CharT* __lo, const _CharT* __hi) const
740 { return this->do_hash(__lo, __hi); }
741
742 // Used to abstract out _CharT bits in virtual member functions, below.
743 int
744 _M_compare(const _CharT*, const _CharT*) const throw();
745
746 size_t
747 _M_transform(_CharT*, const _CharT*, size_t) const throw();
748
749 protected:
750 /// Destructor.
751 virtual
752 ~collate()
753 { _S_destroy_c_locale(_M_c_locale_collate); }
754
755 /**
756 * @brief Compare two strings.
757 *
758 * This function is a hook for derived classes to change the value
759 * returned. @see compare().
760 *
761 * @param __lo1 Start of string 1.
762 * @param __hi1 End of string 1.
763 * @param __lo2 Start of string 2.
764 * @param __hi2 End of string 2.
765 * @return 1 if string1 > string2, -1 if string1 < string2, else 0.
766 */
767 virtual int
768 do_compare(const _CharT* __lo1, const _CharT* __hi1,
769 const _CharT* __lo2, const _CharT* __hi2) const;
770
771 /**
772 * @brief Transform string to comparable form.
773 *
774 * This function is a hook for derived classes to change the value
775 * returned.
776 *
777 * @param __lo Start.
778 * @param __hi End.
779 * @return transformed string.
780 */
781 virtual string_type
782 do_transform(const _CharT* __lo, const _CharT* __hi) const;
783
784 /**
785 * @brief Return hash of a string.
786 *
787 * This function computes and returns a hash on the input string. This
788 * function is a hook for derived classes to change the value returned.
789 *
790 * @param __lo Start of string.
791 * @param __hi End of string.
792 * @return Hash value.
793 */
794 virtual long
795 do_hash(const _CharT* __lo, const _CharT* __hi) const;
796 };
797
798 template<typename _CharT>
799 locale::id collate<_CharT>::id;
800
801 // Specializations.
802 template<>
803 int
804 collate<char>::_M_compare(const char*, const char*) const throw();
805
806 template<>
807 size_t
808 collate<char>::_M_transform(char*, const char*, size_t) const throw();
809
810 #ifdef _GLIBCXX_USE_WCHAR_T
811 template<>
812 int
813 collate<wchar_t>::_M_compare(const wchar_t*, const wchar_t*) const throw();
814
815 template<>
816 size_t
817 collate<wchar_t>::_M_transform(wchar_t*, const wchar_t*, size_t) const throw();
818 #endif
819
820 /// class collate_byname [22.2.4.2].
821 template<typename _CharT>
822 class _GLIBCXX_NAMESPACE_CXX11 collate_byname : public collate<_CharT>
823 {
824 public:
825 ///@{
826 /// Public typedefs
827 typedef _CharT char_type;
828 typedef basic_string<_CharT> string_type;
829 ///@}
830
831 explicit
832 collate_byname(const char* __s, size_t __refs = 0)
833 : collate<_CharT>(__refs)
834 {
835 if (__builtin_strcmp(__s, "C") != 0
836 && __builtin_strcmp(__s, "POSIX") != 0)
837 {
838 this->_S_destroy_c_locale(this->_M_c_locale_collate);
839 this->_S_create_c_locale(this->_M_c_locale_collate, __s);
840 }
841 }
842
843 #if __cplusplus >= 201103L
844 explicit
845 collate_byname(const string& __s, size_t __refs = 0)
846 : collate_byname(__s.c_str(), __refs) { }
847 #endif
848
849 protected:
850 virtual
851 ~collate_byname() { }
852 };
853
854 _GLIBCXX_END_NAMESPACE_VERSION
855 } // namespace
856
857 # include <bits/locale_classes.tcc>
858
859 #endif
860