1 // Locale support -*- C++ -*-
3 // Copyright (C) 1997-2015 Free Software Foundation, Inc.
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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}
31 // ISO C++ 14882: 22.1 Locales
34 #ifndef _LOCALE_CLASSES_H
35 #define _LOCALE_CLASSES_H 1
37 #pragma GCC system_header
39 #include <bits/localefwd.h>
41 #include <ext/atomicity.h>
43 namespace std _GLIBCXX_VISIBILITY(default)
45 _GLIBCXX_BEGIN_NAMESPACE_VERSION
47 // 22.1.1 Class locale
49 * @brief Container class for localization functionality.
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.
57 * Constructing C++ locales does not change the C library locale.
59 * This library supports efficient construction and copying of locales
60 * through a reference counting implementation of the locale class.
66 /// Definition of locale::category.
69 // Forward decls and friends:
77 template<typename _Facet>
79 has_facet(const locale&) throw();
81 template<typename _Facet>
83 use_facet(const locale&);
85 template<typename _Cache>
86 friend struct __use_cache;
90 * @brief Category values.
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.
96 * NB: Order must match _S_facet_categories definition in locale.cc
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);
109 // Construct/copy/destroy:
112 * @brief Default constructor.
114 * Constructs a copy of the global locale. If no locale has been
115 * explicitly set, this is the C locale.
120 * @brief Copy constructor.
122 * Constructs a copy of @a other.
124 * @param __other The locale to copy.
126 locale(const locale& __other) throw();
129 * @brief Named locale constructor.
131 * Constructs a copy of the named C library locale.
133 * @param __s Name of the locale to construct.
134 * @throw std::runtime_error if __s is null or an undefined locale.
137 locale(const char* __s);
140 * @brief Construct locale with facets from another locale.
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.
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.
151 locale(const locale& __base, const char* __s, category __cat);
153 #if __cplusplus >= 201103L
155 * @brief Named locale constructor.
157 * Constructs a copy of the named C library locale.
159 * @param __s Name of the locale to construct.
160 * @throw std::runtime_error if __s is an undefined locale.
163 locale(const std::string& __s) : locale(__s.c_str()) { }
166 * @brief Construct locale with facets from another locale.
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.
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.
177 locale(const locale& __base, const std::string& __s, category __cat)
178 : locale(__base, __s.c_str(), __cat) { }
182 * @brief Construct locale with facets from another locale.
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.
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.
192 locale(const locale& __base, const locale& __add, category __cat);
195 * @brief Construct locale with another facet.
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.
202 * @param __other The locale to copy.
203 * @param __f The facet to add in.
205 template<typename _Facet>
206 locale(const locale& __other, _Facet* __f);
208 /// Locale destructor.
212 * @brief Assignment operator.
214 * Set this locale to be a copy of @a other.
216 * @param __other The locale to copy.
217 * @return A reference to this locale.
220 operator=(const locale& __other) throw();
223 * @brief Construct locale with another facet.
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
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.
234 template<typename _Facet>
236 combine(const locale& __other) const;
238 // Locale operations:
240 * @brief Return locale name.
241 * @return Locale name or "*" if unnamed.
243 _GLIBCXX_DEFAULT_ABI_TAG
248 * @brief Locale equality.
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.
255 operator==(const locale& __other) const throw();
258 * @brief Locale inequality.
260 * @param __other The locale to compare against.
261 * @return ! (*this == __other)
264 operator!=(const locale& __other) const throw()
265 { return !(this->operator==(__other)); }
268 * @brief Compare two strings according to collate.
270 * Template operator to compare two strings using the compare function of
271 * the collate facet in this locale. One use is to provide the locale to
272 * the sort function. For example, a vector v of strings could be sorted
273 * according to locale loc by doing:
275 * std::sort(v.begin(), v.end(), loc);
278 * @param __s1 First string to compare.
279 * @param __s2 Second string to compare.
280 * @return True if collate<_Char> facet compares __s1 < __s2, else false.
282 template<typename _Char, typename _Traits, typename _Alloc>
284 operator()(const basic_string<_Char, _Traits, _Alloc>& __s1,
285 const basic_string<_Char, _Traits, _Alloc>& __s2) const;
287 // Global locale objects:
289 * @brief Set global locale
291 * This function sets the global locale to the argument and returns a
292 * copy of the previous global locale. If the argument has a name, it
293 * will also call std::setlocale(LC_ALL, loc.name()).
295 * @param __loc The new locale to make global.
296 * @return Copy of the old global locale.
299 global(const locale& __loc);
302 * @brief Return reference to the C locale.
308 // The (shared) implementation
311 // The "C" reference locale
312 static _Impl* _S_classic;
314 // Current global locale
315 static _Impl* _S_global;
317 // Names of underlying locale categories.
318 // NB: locale::global() has to know how to modify all the
319 // underlying categories, not just the ones required by the C++
321 static const char* const* const _S_categories;
323 // Number of standard categories. For C++, these categories are
324 // collate, ctype, monetary, numeric, time, and messages. These
325 // directly correspond to ISO C99 macros LC_COLLATE, LC_CTYPE,
326 // LC_MONETARY, LC_NUMERIC, and LC_TIME. In addition, POSIX (IEEE
327 // 1003.1-2001) specifies LC_MESSAGES.
328 // In addition to the standard categories, the underlying
329 // operating system is allowed to define extra LC_*
330 // macros. For GNU systems, the following are also valid:
331 // LC_PAPER, LC_NAME, LC_ADDRESS, LC_TELEPHONE, LC_MEASUREMENT,
332 // and LC_IDENTIFICATION.
333 enum { _S_categories_size = 6 + _GLIBCXX_NUM_CATEGORIES };
336 static __gthread_once_t _S_once;
340 locale(_Impl*) throw();
346 _S_initialize_once() throw();
349 _S_normalize_category(category);
352 _M_coalesce(const locale& __base, const locale& __add, category __cat);
354 #if _GLIBCXX_USE_CXX11_ABI
355 static const id* const _S_twinned_facets[];
360 // 22.1.1.1.2 Class locale::facet
362 * @brief Localization functionality base class.
365 * The facet class is the base class for a localization feature, such as
366 * money, time, and number printing. It provides common support for facets
367 * and reference management.
369 * Facets may not be copied or assigned.
375 friend class locale::_Impl;
377 mutable _Atomic_word _M_refcount;
379 // Contains data from the underlying "C" library for the classic locale.
380 static __c_locale _S_c_locale;
382 // String literal for the name of the classic locale.
383 static const char _S_c_name[2];
386 static __gthread_once_t _S_once;
390 _S_initialize_once();
394 * @brief Facet constructor.
396 * This is the constructor provided by the standard. If refs is 0, the
397 * facet is destroyed when the last referencing locale is destroyed.
398 * Otherwise the facet will never be destroyed.
400 * @param __refs The initial value for reference count.
403 facet(size_t __refs = 0) throw() : _M_refcount(__refs ? 1 : 0)
406 /// Facet destructor.
411 _S_create_c_locale(__c_locale& __cloc, const char* __s,
412 __c_locale __old = 0);
415 _S_clone_c_locale(__c_locale& __cloc) throw();
418 _S_destroy_c_locale(__c_locale& __cloc);
421 _S_lc_ctype_c_locale(__c_locale __cloc, const char* __s);
423 // Returns data from the underlying "C" library data for the
428 _GLIBCXX_CONST static const char*
429 _S_get_c_name() throw();
433 _M_add_reference() const throw()
434 { __gnu_cxx::__atomic_add_dispatch(&_M_refcount, 1); }
437 _M_remove_reference() const throw()
439 // Be race-detector-friendly. For more info see bits/c++config.
440 _GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_M_refcount);
441 if (__gnu_cxx::__exchange_and_add_dispatch(&_M_refcount, -1) == 1)
443 _GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_M_refcount);
451 facet(const facet&); // Not defined.
454 operator=(const facet&); // Not defined.
458 const facet* _M_sso_shim(const id*) const;
459 const facet* _M_cow_shim(const id*) const;
463 // 22.1.1.1.3 Class locale::id
465 * @brief Facet ID class.
468 * The ID class provides facets with an index used to identify them.
469 * Every facet class must define a public static member locale::id, or be
470 * derived from a facet that provides this member, otherwise the facet
471 * cannot be used in a locale. The locale::id ensures that each class
472 * type gets a unique identifier.
478 friend class locale::_Impl;
480 template<typename _Facet>
482 use_facet(const locale&);
484 template<typename _Facet>
486 has_facet(const locale&) throw();
488 // NB: There is no accessor for _M_index because it may be used
489 // before the constructor is run; the effect of calling a member
490 // function (even an inline) would be undefined.
491 mutable size_t _M_index;
493 // Last id number assigned.
494 static _Atomic_word _S_refcount;
497 operator=(const id&); // Not defined.
499 id(const id&); // Not defined.
502 // NB: This class is always a static data member, and thus can be
503 // counted on to be zero-initialized.
508 _M_id() const throw();
512 // Implementation object for locale.
518 friend class locale::facet;
520 template<typename _Facet>
522 has_facet(const locale&) throw();
524 template<typename _Facet>
526 use_facet(const locale&);
528 template<typename _Cache>
529 friend struct __use_cache;
533 _Atomic_word _M_refcount;
534 const facet** _M_facets;
535 size_t _M_facets_size;
536 const facet** _M_caches;
538 static const locale::id* const _S_id_ctype[];
539 static const locale::id* const _S_id_numeric[];
540 static const locale::id* const _S_id_collate[];
541 static const locale::id* const _S_id_time[];
542 static const locale::id* const _S_id_monetary[];
543 static const locale::id* const _S_id_messages[];
544 static const locale::id* const* const _S_facet_categories[];
547 _M_add_reference() throw()
548 { __gnu_cxx::__atomic_add_dispatch(&_M_refcount, 1); }
551 _M_remove_reference() throw()
553 // Be race-detector-friendly. For more info see bits/c++config.
554 _GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_M_refcount);
555 if (__gnu_cxx::__exchange_and_add_dispatch(&_M_refcount, -1) == 1)
557 _GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_M_refcount);
565 _Impl(const _Impl&, size_t);
566 _Impl(const char*, size_t);
567 _Impl(size_t) throw();
571 _Impl(const _Impl&); // Not defined.
574 operator=(const _Impl&); // Not defined.
581 // We must actually compare all the _M_names: can be all equal!
582 for (size_t __i = 0; __ret && __i < _S_categories_size - 1; ++__i)
583 __ret = __builtin_strcmp(_M_names[__i], _M_names[__i + 1]) == 0;
588 _M_replace_categories(const _Impl*, category);
591 _M_replace_category(const _Impl*, const locale::id* const*);
594 _M_replace_facet(const _Impl*, const locale::id*);
597 _M_install_facet(const locale::id*, const facet*);
599 template<typename _Facet>
601 _M_init_facet(_Facet* __facet)
602 { _M_install_facet(&_Facet::id, __facet); }
604 template<typename _Facet>
606 _M_init_facet_unchecked(_Facet* __facet)
608 __facet->_M_add_reference();
609 _M_facets[_Facet::id._M_id()] = __facet;
613 _M_install_cache(const facet*, size_t);
615 void _M_init_extra(facet**);
616 void _M_init_extra(void*, void*, const char*, const char*);
621 * @brief Facet for localized string comparison.
623 * This facet encapsulates the code to compare strings in a localized
626 * The collate template uses protected virtual functions to provide
627 * the actual results. The public accessors forward the call to
628 * the virtual functions. These virtual functions are hooks for
629 * developers to implement the behavior they require from the
632 template<typename _CharT>
633 class _GLIBCXX_NAMESPACE_CXX11 collate : public locale::facet
639 typedef _CharT char_type;
640 typedef basic_string<_CharT> string_type;
644 // Underlying "C" library locale information saved from
645 // initialization, needed by collate_byname as well.
646 __c_locale _M_c_locale_collate;
649 /// Numpunct facet id.
650 static locale::id id;
653 * @brief Constructor performs initialization.
655 * This is the constructor provided by the standard.
657 * @param __refs Passed to the base facet class.
660 collate(size_t __refs = 0)
661 : facet(__refs), _M_c_locale_collate(_S_get_c_locale())
665 * @brief Internal constructor. Not for general use.
667 * This is a constructor for use by the library itself to set up new
670 * @param __cloc The C locale.
671 * @param __refs Passed to the base facet class.
674 collate(__c_locale __cloc, size_t __refs = 0)
675 : facet(__refs), _M_c_locale_collate(_S_clone_c_locale(__cloc))
679 * @brief Compare two strings.
681 * This function compares two strings and returns the result by calling
682 * collate::do_compare().
684 * @param __lo1 Start of string 1.
685 * @param __hi1 End of string 1.
686 * @param __lo2 Start of string 2.
687 * @param __hi2 End of string 2.
688 * @return 1 if string1 > string2, -1 if string1 < string2, else 0.
691 compare(const _CharT* __lo1, const _CharT* __hi1,
692 const _CharT* __lo2, const _CharT* __hi2) const
693 { return this->do_compare(__lo1, __hi1, __lo2, __hi2); }
696 * @brief Transform string to comparable form.
698 * This function is a wrapper for strxfrm functionality. It takes the
699 * input string and returns a modified string that can be directly
700 * compared to other transformed strings. In the C locale, this
701 * function just returns a copy of the input string. In some other
702 * locales, it may replace two chars with one, change a char for
703 * another, etc. It does so by returning collate::do_transform().
705 * @param __lo Start of string.
706 * @param __hi End of string.
707 * @return Transformed string_type.
710 transform(const _CharT* __lo, const _CharT* __hi) const
711 { return this->do_transform(__lo, __hi); }
714 * @brief Return hash of a string.
716 * This function computes and returns a hash on the input string. It
717 * does so by returning collate::do_hash().
719 * @param __lo Start of string.
720 * @param __hi End of string.
721 * @return Hash value.
724 hash(const _CharT* __lo, const _CharT* __hi) const
725 { return this->do_hash(__lo, __hi); }
727 // Used to abstract out _CharT bits in virtual member functions, below.
729 _M_compare(const _CharT*, const _CharT*) const throw();
732 _M_transform(_CharT*, const _CharT*, size_t) const throw();
738 { _S_destroy_c_locale(_M_c_locale_collate); }
741 * @brief Compare two strings.
743 * This function is a hook for derived classes to change the value
744 * returned. @see compare().
746 * @param __lo1 Start of string 1.
747 * @param __hi1 End of string 1.
748 * @param __lo2 Start of string 2.
749 * @param __hi2 End of string 2.
750 * @return 1 if string1 > string2, -1 if string1 < string2, else 0.
753 do_compare(const _CharT* __lo1, const _CharT* __hi1,
754 const _CharT* __lo2, const _CharT* __hi2) const;
757 * @brief Transform string to comparable form.
759 * This function is a hook for derived classes to change the value
764 * @return transformed string.
767 do_transform(const _CharT* __lo, const _CharT* __hi) const;
770 * @brief Return hash of a string.
772 * This function computes and returns a hash on the input string. This
773 * function is a hook for derived classes to change the value returned.
775 * @param __lo Start of string.
776 * @param __hi End of string.
777 * @return Hash value.
780 do_hash(const _CharT* __lo, const _CharT* __hi) const;
783 template<typename _CharT>
784 locale::id collate<_CharT>::id;
789 collate<char>::_M_compare(const char*, const char*) const throw();
793 collate<char>::_M_transform(char*, const char*, size_t) const throw();
795 #ifdef _GLIBCXX_USE_WCHAR_T
798 collate<wchar_t>::_M_compare(const wchar_t*, const wchar_t*) const throw();
802 collate<wchar_t>::_M_transform(wchar_t*, const wchar_t*, size_t) const throw();
805 /// class collate_byname [22.2.4.2].
806 template<typename _CharT>
807 class _GLIBCXX_NAMESPACE_CXX11 collate_byname : public collate<_CharT>
812 typedef _CharT char_type;
813 typedef basic_string<_CharT> string_type;
817 collate_byname(const char* __s, size_t __refs = 0)
818 : collate<_CharT>(__refs)
820 if (__builtin_strcmp(__s, "C") != 0
821 && __builtin_strcmp(__s, "POSIX") != 0)
823 this->_S_destroy_c_locale(this->_M_c_locale_collate);
824 this->_S_create_c_locale(this->_M_c_locale_collate, __s);
828 #if __cplusplus >= 201103L
830 collate_byname(const string& __s, size_t __refs = 0)
831 : collate_byname(__s.c_str(), __refs) { }
836 ~collate_byname() { }
839 _GLIBCXX_END_NAMESPACE_VERSION
842 # include <bits/locale_classes.tcc>