libstdc++
locale_classes.h
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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
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7 // terms of the GNU General Public License as published by the
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9 // any later version.
10 
11 // This library is distributed in the hope that it will be useful,
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15 
16 // Under Section 7 of GPL version 3, you are granted additional
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19 
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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 
47 namespace 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  */
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(&_M_refcount, 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(&_M_refcount, -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  */
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(&_M_refcount, 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(&_M_refcount, -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;
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
784  { _S_destroy_c_locale(_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;
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
ISO C++ entities toplevel namespace is std.
~locale()
Locale destructor.
static const locale & classic()
Return reference to the C locale.
virtual ~facet()
Facet destructor.
Localization functionality base class.The facet class is the base class for a localization feature...
static const category none
Category values.
string name() const
Return locale name.
_CharT char_type
Public typedefs.
constexpr _Iterator __base(_Iterator __it)
static const category time
Category values.
static locale global(const locale &__loc)
Set global locale.
string_type transform(const _CharT *__lo, const _CharT *__hi) const
Transform string to comparable form.
Container class for localization functionality.The locale class is first a class wrapper for C librar...
static const category messages
Category values.
int category
Definition of locale::category.
friend const _Facet & use_facet(const locale &)
Return a facet.use_facet looks for and returns a reference to a facet of type Facet where Facet is th...
static const category monetary
Category values.
Primary class template ctype facet.This template class defines classification and conversion function...
locale(const locale &__base, const std::string &__s, category __cat)
Construct locale with facets from another locale.
class collate_byname [22.2.4.2].
Primary class template messages.This facet encapsulates the code to retrieve messages from message ca...
bool operator()(const basic_string< _Char, _Traits, _Alloc > &__s1, const basic_string< _Char, _Traits, _Alloc > &__s2) const
Compare two strings according to collate.
_CharT char_type
Public typedefs.
locale()
Default constructor.
friend const _Facet & use_facet(const locale &)
Return a facet.use_facet looks for and returns a reference to a facet of type Facet where Facet is th...
friend bool has_facet(const locale &)
Test for the presence of a facet.has_facet tests the locale argument for the presence of the facet ty...
basic_string< _CharT > string_type
Public typedefs.
static const category all
Category values.
virtual ~collate()
Destructor.
static locale::id id
Numpunct facet id.
int compare(const _CharT *__lo1, const _CharT *__hi1, const _CharT *__lo2, const _CharT *__hi2) const
Compare two strings.
id()
Constructor.
friend bool has_facet(const locale &)
Test for the presence of a facet.has_facet tests the locale argument for the presence of the facet ty...
bool operator==(const locale &__other) const
Locale equality.
locale(const std::string &__s)
Named locale constructor.
long hash(const _CharT *__lo, const _CharT *__hi) const
Return hash of a string.
facet(size_t __refs=0)
Facet constructor.
static const category numeric
Category values.
Facet ID class.The ID class provides facets with an index used to identify them. Every facet class mu...
basic_string< _CharT > string_type
Public typedefs.
collate(__c_locale __cloc, size_t __refs=0)
Internal constructor. Not for general use.
Facet for localized string comparison.
collate(size_t __refs=0)
Constructor performs initialization.
locale combine(const locale &__other) const
Construct locale with another facet.