libstdc++
locale_classes.h
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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
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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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13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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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 
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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 #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
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&
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  */
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
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  */
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;
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
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;
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
ISO C++ entities toplevel namespace is std.
constexpr _Iterator __base(_Iterator __it)
Container class for localization functionality.
bool operator==(const locale &__other) const
Locale equality.
static locale global(const locale &__loc)
Set global locale.
static const category time
Category values.
string name() const
Return locale name.
static const category monetary
Category values.
~locale()
Locale destructor.
static const category numeric
Category values.
static const category none
Category values.
static const category messages
Category values.
locale(const std::string &__s)
Named locale constructor.
locale(const locale &__base, const std::string &__s, category __cat)
Construct locale with facets from another locale.
int category
Definition of locale::category.
locale combine(const locale &__other) const
Construct locale with another facet.
static const locale & classic()
Return reference to the C locale.
friend const _Facet & use_facet(const locale &)
Return a facet.
static const category all
Category values.
friend bool has_facet(const locale &)
Test for the presence of a facet.
bool operator()(const basic_string< _Char, _Traits, _Alloc > &__s1, const basic_string< _Char, _Traits, _Alloc > &__s2) const
Compare two strings according to collate.
locale(const locale &__base, const locale &__add, category __cat)
Construct locale with facets from another locale.
locale()
Default constructor.
Localization functionality base class.
facet(size_t __refs=0)
Facet constructor.
virtual ~facet()
Facet destructor.
Facet ID class.
id()
Constructor.
friend const _Facet & use_facet(const locale &)
Return a facet.
friend bool has_facet(const locale &)
Test for the presence of a facet.
Facet for localized string comparison.
virtual ~collate()
Destructor.
collate(__c_locale __cloc, size_t __refs=0)
Internal constructor. Not for general use.
_CharT char_type
Public typedefs.
static locale::id id
Numpunct facet id.
long hash(const _CharT *__lo, const _CharT *__hi) const
Return hash of a string.
int compare(const _CharT *__lo1, const _CharT *__hi1, const _CharT *__lo2, const _CharT *__hi2) const
Compare two strings.
string_type transform(const _CharT *__lo, const _CharT *__hi) const
Transform string to comparable form.
basic_string< _CharT > string_type
Public typedefs.
collate(size_t __refs=0)
Constructor performs initialization.
class collate_byname [22.2.4.2].
basic_string< _CharT > string_type
Public typedefs.
_CharT char_type
Public typedefs.
Primary class template ctype facet.
Primary class template messages.