1 // Locale support -*- C++ -*-
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4 // 2006, 2007, 2008, 2009, 2010, 2011
5 // Free Software Foundation, Inc.
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27 /** @file bits/locale_classes.h
28 * This is an internal header file, included by other library headers.
29 * Do not attempt to use it directly. @headername{locale}
33 // ISO C++ 14882: 22.1 Locales
36 #ifndef _LOCALE_CLASSES_H
37 #define _LOCALE_CLASSES_H 1
39 #pragma GCC system_header
41 #include <bits/localefwd.h>
43 #include <ext/atomicity.h>
45 namespace std _GLIBCXX_VISIBILITY(default)
47 _GLIBCXX_BEGIN_NAMESPACE_VERSION
49 // 22.1.1 Class locale
51 * @brief Container class for localization functionality.
54 * The locale class is first a class wrapper for C library locales. It is
55 * also an extensible container for user-defined localization. A locale is
56 * a collection of facets that implement various localization features such
57 * as money, time, and number printing.
59 * Constructing C++ locales does not change the C library locale.
61 * This library supports efficient construction and copying of locales
62 * through a reference counting implementation of the locale class.
68 /// Definition of locale::category.
71 // Forward decls and friends:
79 template<typename _Facet>
81 has_facet(const locale&) throw();
83 template<typename _Facet>
85 use_facet(const locale&);
87 template<typename _Cache>
88 friend struct __use_cache;
92 * @brief Category values.
94 * The standard category values are none, ctype, numeric, collate, time,
95 * monetary, and messages. They form a bitmask that supports union and
96 * intersection. The category all is the union of these values.
98 * NB: Order must match _S_facet_categories definition in locale.cc
100 static const category none = 0;
101 static const category ctype = 1L << 0;
102 static const category numeric = 1L << 1;
103 static const category collate = 1L << 2;
104 static const category time = 1L << 3;
105 static const category monetary = 1L << 4;
106 static const category messages = 1L << 5;
107 static const category all = (ctype | numeric | collate |
108 time | monetary | messages);
111 // Construct/copy/destroy:
114 * @brief Default constructor.
116 * Constructs a copy of the global locale. If no locale has been
117 * explicitly set, this is the C locale.
122 * @brief Copy constructor.
124 * Constructs a copy of @a other.
126 * @param other The locale to copy.
128 locale(const locale& __other) throw();
131 * @brief Named locale constructor.
133 * Constructs a copy of the named C library locale.
135 * @param s Name of the locale to construct.
136 * @throw std::runtime_error if s is null or an undefined locale.
139 locale(const char* __s);
142 * @brief Construct locale with facets from another locale.
144 * Constructs a copy of the locale @a base. The facets specified by @a
145 * cat are replaced with those from the locale named by @a s. If base is
146 * named, this locale instance will also be named.
148 * @param base The locale to copy.
149 * @param s Name of the locale to use facets from.
150 * @param cat Set of categories defining the facets to use from s.
151 * @throw std::runtime_error if s is null or an undefined locale.
153 locale(const locale& __base, const char* __s, category __cat);
156 * @brief Construct locale with facets from another locale.
158 * Constructs a copy of the locale @a base. The facets specified by @a
159 * cat are replaced with those from the locale @a add. If @a base and @a
160 * add are named, this locale instance will also be named.
162 * @param base The locale to copy.
163 * @param add The locale to use facets from.
164 * @param cat Set of categories defining the facets to use from add.
166 locale(const locale& __base, const locale& __add, category __cat);
169 * @brief Construct locale with another facet.
171 * Constructs a copy of the locale @a other. The facet @f is added to
172 * @other, replacing an existing facet of type Facet if there is one. If
173 * @f is null, this locale is a copy of @a other.
175 * @param other The locale to copy.
176 * @param f The facet to add in.
178 template<typename _Facet>
179 locale(const locale& __other, _Facet* __f);
181 /// Locale destructor.
185 * @brief Assignment operator.
187 * Set this locale to be a copy of @a other.
189 * @param other The locale to copy.
190 * @return A reference to this locale.
193 operator=(const locale& __other) throw();
196 * @brief Construct locale with another facet.
198 * Constructs and returns a new copy of this locale. Adds or replaces an
199 * existing facet of type Facet from the locale @a other into the new
202 * @param Facet The facet type to copy from other
203 * @param other The locale to copy from.
204 * @return Newly constructed locale.
205 * @throw std::runtime_error if other has no facet of type Facet.
207 template<typename _Facet>
209 combine(const locale& __other) const;
211 // Locale operations:
213 * @brief Return locale name.
214 * @return Locale name or "*" if unnamed.
220 * @brief Locale equality.
222 * @param other The locale to compare against.
223 * @return True if other and this refer to the same locale instance, are
224 * copies, or have the same name. False otherwise.
227 operator==(const locale& __other) const throw();
230 * @brief Locale inequality.
232 * @param other The locale to compare against.
233 * @return ! (*this == other)
236 operator!=(const locale& __other) const throw()
237 { return !(this->operator==(__other)); }
240 * @brief Compare two strings according to collate.
242 * Template operator to compare two strings using the compare function of
243 * the collate facet in this locale. One use is to provide the locale to
244 * the sort function. For example, a vector v of strings could be sorted
245 * according to locale loc by doing:
247 * std::sort(v.begin(), v.end(), loc);
250 * @param s1 First string to compare.
251 * @param s2 Second string to compare.
252 * @return True if collate<Char> facet compares s1 < s2, else false.
254 template<typename _Char, typename _Traits, typename _Alloc>
256 operator()(const basic_string<_Char, _Traits, _Alloc>& __s1,
257 const basic_string<_Char, _Traits, _Alloc>& __s2) const;
259 // Global locale objects:
261 * @brief Set global locale
263 * This function sets the global locale to the argument and returns a
264 * copy of the previous global locale. If the argument has a name, it
265 * will also call std::setlocale(LC_ALL, loc.name()).
267 * @param locale The new locale to make global.
268 * @return Copy of the old global locale.
271 global(const locale&);
274 * @brief Return reference to the C locale.
280 // The (shared) implementation
283 // The "C" reference locale
284 static _Impl* _S_classic;
286 // Current global locale
287 static _Impl* _S_global;
289 // Names of underlying locale categories.
290 // NB: locale::global() has to know how to modify all the
291 // underlying categories, not just the ones required by the C++
293 static const char* const* const _S_categories;
295 // Number of standard categories. For C++, these categories are
296 // collate, ctype, monetary, numeric, time, and messages. These
297 // directly correspond to ISO C99 macros LC_COLLATE, LC_CTYPE,
298 // LC_MONETARY, LC_NUMERIC, and LC_TIME. In addition, POSIX (IEEE
299 // 1003.1-2001) specifies LC_MESSAGES.
300 // In addition to the standard categories, the underlying
301 // operating system is allowed to define extra LC_*
302 // macros. For GNU systems, the following are also valid:
303 // LC_PAPER, LC_NAME, LC_ADDRESS, LC_TELEPHONE, LC_MEASUREMENT,
304 // and LC_IDENTIFICATION.
305 enum { _S_categories_size = 6 + _GLIBCXX_NUM_CATEGORIES };
308 static __gthread_once_t _S_once;
312 locale(_Impl*) throw();
318 _S_initialize_once() throw();
321 _S_normalize_category(category);
324 _M_coalesce(const locale& __base, const locale& __add, category __cat);
328 // 22.1.1.1.2 Class locale::facet
330 * @brief Localization functionality base class.
333 * The facet class is the base class for a localization feature, such as
334 * money, time, and number printing. It provides common support for facets
335 * and reference management.
337 * Facets may not be copied or assigned.
343 friend class locale::_Impl;
345 mutable _Atomic_word _M_refcount;
347 // Contains data from the underlying "C" library for the classic locale.
348 static __c_locale _S_c_locale;
350 // String literal for the name of the classic locale.
351 static const char _S_c_name[2];
354 static __gthread_once_t _S_once;
358 _S_initialize_once();
362 * @brief Facet constructor.
364 * This is the constructor provided by the standard. If refs is 0, the
365 * facet is destroyed when the last referencing locale is destroyed.
366 * Otherwise the facet will never be destroyed.
368 * @param refs The initial value for reference count.
371 facet(size_t __refs = 0) throw() : _M_refcount(__refs ? 1 : 0)
374 /// Facet destructor.
379 _S_create_c_locale(__c_locale& __cloc, const char* __s,
380 __c_locale __old = 0);
383 _S_clone_c_locale(__c_locale& __cloc) throw();
386 _S_destroy_c_locale(__c_locale& __cloc);
389 _S_lc_ctype_c_locale(__c_locale __cloc, const char* __s);
391 // Returns data from the underlying "C" library data for the
396 _GLIBCXX_CONST static const char*
397 _S_get_c_name() throw();
401 _M_add_reference() const throw()
402 { __gnu_cxx::__atomic_add_dispatch(&_M_refcount, 1); }
405 _M_remove_reference() const throw()
407 // Be race-detector-friendly. For more info see bits/c++config.
408 _GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_M_refcount);
409 if (__gnu_cxx::__exchange_and_add_dispatch(&_M_refcount, -1) == 1)
411 _GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_M_refcount);
419 facet(const facet&); // Not defined.
422 operator=(const facet&); // Not defined.
426 // 22.1.1.1.3 Class locale::id
428 * @brief Facet ID class.
431 * The ID class provides facets with an index used to identify them.
432 * Every facet class must define a public static member locale::id, or be
433 * derived from a facet that provides this member, otherwise the facet
434 * cannot be used in a locale. The locale::id ensures that each class
435 * type gets a unique identifier.
441 friend class locale::_Impl;
443 template<typename _Facet>
445 use_facet(const locale&);
447 template<typename _Facet>
449 has_facet(const locale&) throw();
451 // NB: There is no accessor for _M_index because it may be used
452 // before the constructor is run; the effect of calling a member
453 // function (even an inline) would be undefined.
454 mutable size_t _M_index;
456 // Last id number assigned.
457 static _Atomic_word _S_refcount;
460 operator=(const id&); // Not defined.
462 id(const id&); // Not defined.
465 // NB: This class is always a static data member, and thus can be
466 // counted on to be zero-initialized.
471 _M_id() const throw();
475 // Implementation object for locale.
481 friend class locale::facet;
483 template<typename _Facet>
485 has_facet(const locale&) throw();
487 template<typename _Facet>
489 use_facet(const locale&);
491 template<typename _Cache>
492 friend struct __use_cache;
496 _Atomic_word _M_refcount;
497 const facet** _M_facets;
498 size_t _M_facets_size;
499 const facet** _M_caches;
501 static const locale::id* const _S_id_ctype[];
502 static const locale::id* const _S_id_numeric[];
503 static const locale::id* const _S_id_collate[];
504 static const locale::id* const _S_id_time[];
505 static const locale::id* const _S_id_monetary[];
506 static const locale::id* const _S_id_messages[];
507 static const locale::id* const* const _S_facet_categories[];
510 _M_add_reference() throw()
511 { __gnu_cxx::__atomic_add_dispatch(&_M_refcount, 1); }
514 _M_remove_reference() throw()
516 // Be race-detector-friendly. For more info see bits/c++config.
517 _GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_M_refcount);
518 if (__gnu_cxx::__exchange_and_add_dispatch(&_M_refcount, -1) == 1)
520 _GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_M_refcount);
528 _Impl(const _Impl&, size_t);
529 _Impl(const char*, size_t);
530 _Impl(size_t) throw();
534 _Impl(const _Impl&); // Not defined.
537 operator=(const _Impl&); // Not defined.
544 // We must actually compare all the _M_names: can be all equal!
545 for (size_t __i = 0; __ret && __i < _S_categories_size - 1; ++__i)
546 __ret = __builtin_strcmp(_M_names[__i], _M_names[__i + 1]) == 0;
551 _M_replace_categories(const _Impl*, category);
554 _M_replace_category(const _Impl*, const locale::id* const*);
557 _M_replace_facet(const _Impl*, const locale::id*);
560 _M_install_facet(const locale::id*, const facet*);
562 template<typename _Facet>
564 _M_init_facet(_Facet* __facet)
565 { _M_install_facet(&_Facet::id, __facet); }
568 _M_install_cache(const facet*, size_t);
573 * @brief Test for the presence of a facet.
575 * has_facet tests the locale argument for the presence of the facet type
576 * provided as the template parameter. Facets derived from the facet
577 * parameter will also return true.
579 * @param Facet The facet type to test the presence of.
580 * @param locale The locale to test.
581 * @return true if locale contains a facet of type Facet, else false.
583 template<typename _Facet>
585 has_facet(const locale& __loc) throw();
588 * @brief Return a facet.
590 * use_facet looks for and returns a reference to a facet of type Facet
591 * where Facet is the template parameter. If has_facet(locale) is true,
592 * there is a suitable facet to return. It throws std::bad_cast if the
593 * locale doesn't contain a facet of type Facet.
595 * @param Facet The facet type to access.
596 * @param locale The locale to use.
597 * @return Reference to facet of type Facet.
598 * @throw std::bad_cast if locale doesn't contain a facet of type Facet.
600 template<typename _Facet>
602 use_facet(const locale& __loc);
606 * @brief Facet for localized string comparison.
608 * This facet encapsulates the code to compare strings in a localized
611 * The collate template uses protected virtual functions to provide
612 * the actual results. The public accessors forward the call to
613 * the virtual functions. These virtual functions are hooks for
614 * developers to implement the behavior they require from the
617 template<typename _CharT>
618 class collate : public locale::facet
624 typedef _CharT char_type;
625 typedef basic_string<_CharT> string_type;
629 // Underlying "C" library locale information saved from
630 // initialization, needed by collate_byname as well.
631 __c_locale _M_c_locale_collate;
634 /// Numpunct facet id.
635 static locale::id id;
638 * @brief Constructor performs initialization.
640 * This is the constructor provided by the standard.
642 * @param refs Passed to the base facet class.
645 collate(size_t __refs = 0)
646 : facet(__refs), _M_c_locale_collate(_S_get_c_locale())
650 * @brief Internal constructor. Not for general use.
652 * This is a constructor for use by the library itself to set up new
655 * @param cloc The C locale.
656 * @param refs Passed to the base facet class.
659 collate(__c_locale __cloc, size_t __refs = 0)
660 : facet(__refs), _M_c_locale_collate(_S_clone_c_locale(__cloc))
664 * @brief Compare two strings.
666 * This function compares two strings and returns the result by calling
667 * collate::do_compare().
669 * @param lo1 Start of string 1.
670 * @param hi1 End of string 1.
671 * @param lo2 Start of string 2.
672 * @param hi2 End of string 2.
673 * @return 1 if string1 > string2, -1 if string1 < string2, else 0.
676 compare(const _CharT* __lo1, const _CharT* __hi1,
677 const _CharT* __lo2, const _CharT* __hi2) const
678 { return this->do_compare(__lo1, __hi1, __lo2, __hi2); }
681 * @brief Transform string to comparable form.
683 * This function is a wrapper for strxfrm functionality. It takes the
684 * input string and returns a modified string that can be directly
685 * compared to other transformed strings. In the C locale, this
686 * function just returns a copy of the input string. In some other
687 * locales, it may replace two chars with one, change a char for
688 * another, etc. It does so by returning collate::do_transform().
690 * @param lo Start of string.
691 * @param hi End of string.
692 * @return Transformed string_type.
695 transform(const _CharT* __lo, const _CharT* __hi) const
696 { return this->do_transform(__lo, __hi); }
699 * @brief Return hash of a string.
701 * This function computes and returns a hash on the input string. It
702 * does so by returning collate::do_hash().
704 * @param lo Start of string.
705 * @param hi End of string.
706 * @return Hash value.
709 hash(const _CharT* __lo, const _CharT* __hi) const
710 { return this->do_hash(__lo, __hi); }
712 // Used to abstract out _CharT bits in virtual member functions, below.
714 _M_compare(const _CharT*, const _CharT*) const throw();
717 _M_transform(_CharT*, const _CharT*, size_t) const throw();
723 { _S_destroy_c_locale(_M_c_locale_collate); }
726 * @brief Compare two strings.
728 * This function is a hook for derived classes to change the value
729 * returned. @see compare().
731 * @param lo1 Start of string 1.
732 * @param hi1 End of string 1.
733 * @param lo2 Start of string 2.
734 * @param hi2 End of string 2.
735 * @return 1 if string1 > string2, -1 if string1 < string2, else 0.
738 do_compare(const _CharT* __lo1, const _CharT* __hi1,
739 const _CharT* __lo2, const _CharT* __hi2) const;
742 * @brief Transform string to comparable form.
744 * This function is a hook for derived classes to change the value
747 * @param lo1 Start of string 1.
748 * @param hi1 End of string 1.
749 * @param lo2 Start of string 2.
750 * @param hi2 End of string 2.
751 * @return 1 if string1 > string2, -1 if string1 < string2, else 0.
754 do_transform(const _CharT* __lo, const _CharT* __hi) const;
757 * @brief Return hash of a string.
759 * This function computes and returns a hash on the input string. This
760 * function is a hook for derived classes to change the value returned.
762 * @param lo Start of string.
763 * @param hi End of string.
764 * @return Hash value.
767 do_hash(const _CharT* __lo, const _CharT* __hi) const;
770 template<typename _CharT>
771 locale::id collate<_CharT>::id;
776 collate<char>::_M_compare(const char*, const char*) const throw();
780 collate<char>::_M_transform(char*, const char*, size_t) const throw();
782 #ifdef _GLIBCXX_USE_WCHAR_T
785 collate<wchar_t>::_M_compare(const wchar_t*, const wchar_t*) const throw();
789 collate<wchar_t>::_M_transform(wchar_t*, const wchar_t*, size_t) const throw();
792 /// class collate_byname [22.2.4.2].
793 template<typename _CharT>
794 class collate_byname : public collate<_CharT>
799 typedef _CharT char_type;
800 typedef basic_string<_CharT> string_type;
804 collate_byname(const char* __s, size_t __refs = 0)
805 : collate<_CharT>(__refs)
807 if (__builtin_strcmp(__s, "C") != 0
808 && __builtin_strcmp(__s, "POSIX") != 0)
810 this->_S_destroy_c_locale(this->_M_c_locale_collate);
811 this->_S_create_c_locale(this->_M_c_locale_collate, __s);
817 ~collate_byname() { }
820 _GLIBCXX_END_NAMESPACE_VERSION
823 # include <bits/locale_classes.tcc>