1 // Locale support -*- C++ -*-
3 // Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
4 // 2006, 2007, 2008, 2009
5 // Free Software Foundation, Inc.
7 // This file is part of the GNU ISO C++ Library. This library is free
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9 // terms of the GNU General Public License as published by the
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13 // This library is distributed in the hope that it will be useful,
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20 // 3.1, as published by the Free Software Foundation.
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27 /** @file locale_classes.h
28 * This is an internal header file, included by other library headers.
29 * You should not attempt to use it directly.
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 _GLIBCXX_BEGIN_NAMESPACE(std)
47 // 22.1.1 Class locale
49 * @brief Container class for localization functionality.
51 * The locale class is first a class wrapper for C library locales. It is
52 * also an extensible container for user-defined localization. A locale is
53 * a collection of facets that implement various localization features such
54 * as money, time, and number printing.
56 * Constructing C++ locales does not change the C library locale.
58 * This library supports efficient construction and copying of locales
59 * through a reference counting implementation of the locale class.
65 /// Definition of locale::category.
68 // Forward decls and friends:
76 template<typename _Facet>
78 has_facet(const locale&) throw();
80 template<typename _Facet>
82 use_facet(const locale&);
84 template<typename _Cache>
85 friend struct __use_cache;
89 * @brief Category values.
91 * The standard category values are none, ctype, numeric, collate, time,
92 * monetary, and messages. They form a bitmask that supports union and
93 * intersection. The category all is the union of these values.
95 * NB: Order must match _S_facet_categories definition in locale.cc
97 static const category none = 0;
98 static const category ctype = 1L << 0;
99 static const category numeric = 1L << 1;
100 static const category collate = 1L << 2;
101 static const category time = 1L << 3;
102 static const category monetary = 1L << 4;
103 static const category messages = 1L << 5;
104 static const category all = (ctype | numeric | collate |
105 time | monetary | messages);
108 // Construct/copy/destroy:
111 * @brief Default constructor.
113 * Constructs a copy of the global locale. If no locale has been
114 * explicitly set, this is the "C" locale.
119 * @brief Copy constructor.
121 * Constructs a copy of @a other.
123 * @param other The locale to copy.
125 locale(const locale& __other) throw();
128 * @brief Named locale constructor.
130 * Constructs a copy of the named C library locale.
132 * @param s Name of the locale to construct.
133 * @throw std::runtime_error if s is null or an undefined locale.
136 locale(const char* __s);
139 * @brief Construct locale with facets from another locale.
141 * Constructs a copy of the locale @a base. The facets specified by @a
142 * cat are replaced with those from the locale named by @a s. If base is
143 * named, this locale instance will also be named.
145 * @param base The locale to copy.
146 * @param s Name of the locale to use facets from.
147 * @param cat Set of categories defining the facets to use from s.
148 * @throw std::runtime_error if s is null or an undefined locale.
150 locale(const locale& __base, const char* __s, category __cat);
153 * @brief Construct locale with facets from another locale.
155 * Constructs a copy of the locale @a base. The facets specified by @a
156 * cat are replaced with those from the locale @a add. If @a base and @a
157 * add are named, this locale instance will also be named.
159 * @param base The locale to copy.
160 * @param add The locale to use facets from.
161 * @param cat Set of categories defining the facets to use from add.
163 locale(const locale& __base, const locale& __add, category __cat);
166 * @brief Construct locale with another facet.
168 * Constructs a copy of the locale @a other. The facet @f is added to
169 * @other, replacing an existing facet of type Facet if there is one. If
170 * @f is null, this locale is a copy of @a other.
172 * @param other The locale to copy.
173 * @param f The facet to add in.
175 template<typename _Facet>
176 locale(const locale& __other, _Facet* __f);
178 /// Locale destructor.
182 * @brief Assignment operator.
184 * Set this locale to be a copy of @a other.
186 * @param other The locale to copy.
187 * @return A reference to this locale.
190 operator=(const locale& __other) throw();
193 * @brief Construct locale with another facet.
195 * Constructs and returns a new copy of this locale. Adds or replaces an
196 * existing facet of type Facet from the locale @a other into the new
199 * @param Facet The facet type to copy from other
200 * @param other The locale to copy from.
201 * @return Newly constructed locale.
202 * @throw std::runtime_error if other has no facet of type Facet.
204 template<typename _Facet>
206 combine(const locale& __other) const;
208 // Locale operations:
210 * @brief Return locale name.
211 * @return Locale name or "*" if unnamed.
217 * @brief Locale equality.
219 * @param other The locale to compare against.
220 * @return True if other and this refer to the same locale instance, are
221 * copies, or have the same name. False otherwise.
224 operator==(const locale& __other) const throw ();
227 * @brief Locale inequality.
229 * @param other The locale to compare against.
230 * @return ! (*this == other)
233 operator!=(const locale& __other) const throw ()
234 { return !(this->operator==(__other)); }
237 * @brief Compare two strings according to collate.
239 * Template operator to compare two strings using the compare function of
240 * the collate facet in this locale. One use is to provide the locale to
241 * the sort function. For example, a vector v of strings could be sorted
242 * according to locale loc by doing:
244 * std::sort(v.begin(), v.end(), loc);
247 * @param s1 First string to compare.
248 * @param s2 Second string to compare.
249 * @return True if collate<Char> facet compares s1 < s2, else false.
251 template<typename _Char, typename _Traits, typename _Alloc>
253 operator()(const basic_string<_Char, _Traits, _Alloc>& __s1,
254 const basic_string<_Char, _Traits, _Alloc>& __s2) const;
256 // Global locale objects:
258 * @brief Set global locale
260 * This function sets the global locale to the argument and returns a
261 * copy of the previous global locale. If the argument has a name, it
262 * will also call std::setlocale(LC_ALL, loc.name()).
264 * @param locale The new locale to make global.
265 * @return Copy of the old global locale.
268 global(const locale&);
271 * @brief Return reference to the "C" locale.
277 // The (shared) implementation
280 // The "C" reference locale
281 static _Impl* _S_classic;
283 // Current global locale
284 static _Impl* _S_global;
286 // Names of underlying locale categories.
287 // NB: locale::global() has to know how to modify all the
288 // underlying categories, not just the ones required by the C++
290 static const char* const* const _S_categories;
292 // Number of standard categories. For C++, these categories are
293 // collate, ctype, monetary, numeric, time, and messages. These
294 // directly correspond to ISO C99 macros LC_COLLATE, LC_CTYPE,
295 // LC_MONETARY, LC_NUMERIC, and LC_TIME. In addition, POSIX (IEEE
296 // 1003.1-2001) specifies LC_MESSAGES.
297 // In addition to the standard categories, the underlying
298 // operating system is allowed to define extra LC_*
299 // macros. For GNU systems, the following are also valid:
300 // LC_PAPER, LC_NAME, LC_ADDRESS, LC_TELEPHONE, LC_MEASUREMENT,
301 // and LC_IDENTIFICATION.
302 enum { _S_categories_size = 6 + _GLIBCXX_NUM_CATEGORIES };
305 static __gthread_once_t _S_once;
309 locale(_Impl*) throw();
315 _S_initialize_once();
318 _S_normalize_category(category);
321 _M_coalesce(const locale& __base, const locale& __add, category __cat);
325 // 22.1.1.1.2 Class locale::facet
327 * @brief Localization functionality base class.
329 * The facet class is the base class for a localization feature, such as
330 * money, time, and number printing. It provides common support for facets
331 * and reference management.
333 * Facets may not be copied or assigned.
339 friend class locale::_Impl;
341 mutable _Atomic_word _M_refcount;
343 // Contains data from the underlying "C" library for the classic locale.
344 static __c_locale _S_c_locale;
346 // String literal for the name of the classic locale.
347 static const char _S_c_name[2];
350 static __gthread_once_t _S_once;
354 _S_initialize_once();
358 * @brief Facet constructor.
360 * This is the constructor provided by the standard. If refs is 0, the
361 * facet is destroyed when the last referencing locale is destroyed.
362 * Otherwise the facet will never be destroyed.
364 * @param refs The initial value for reference count.
367 facet(size_t __refs = 0) throw() : _M_refcount(__refs ? 1 : 0)
370 /// Facet destructor.
375 _S_create_c_locale(__c_locale& __cloc, const char* __s,
376 __c_locale __old = 0);
379 _S_clone_c_locale(__c_locale& __cloc);
382 _S_destroy_c_locale(__c_locale& __cloc);
384 // Returns data from the underlying "C" library data for the
394 _M_add_reference() const throw()
395 { __gnu_cxx::__atomic_add_dispatch(&_M_refcount, 1); }
398 _M_remove_reference() const throw()
400 if (__gnu_cxx::__exchange_and_add_dispatch(&_M_refcount, -1) == 1)
409 facet(const facet&); // Not defined.
412 operator=(const facet&); // Not defined.
416 // 22.1.1.1.3 Class locale::id
418 * @brief Facet ID class.
420 * The ID class provides facets with an index used to identify them.
421 * Every facet class must define a public static member locale::id, or be
422 * derived from a facet that provides this member, otherwise the facet
423 * cannot be used in a locale. The locale::id ensures that each class
424 * type gets a unique identifier.
430 friend class locale::_Impl;
432 template<typename _Facet>
434 use_facet(const locale&);
436 template<typename _Facet>
438 has_facet(const locale&) throw ();
440 // NB: There is no accessor for _M_index because it may be used
441 // before the constructor is run; the effect of calling a member
442 // function (even an inline) would be undefined.
443 mutable size_t _M_index;
445 // Last id number assigned.
446 static _Atomic_word _S_refcount;
449 operator=(const id&); // Not defined.
451 id(const id&); // Not defined.
454 // NB: This class is always a static data member, and thus can be
455 // counted on to be zero-initialized.
464 // Implementation object for locale.
470 friend class locale::facet;
472 template<typename _Facet>
474 has_facet(const locale&) throw();
476 template<typename _Facet>
478 use_facet(const locale&);
480 template<typename _Cache>
481 friend struct __use_cache;
485 _Atomic_word _M_refcount;
486 const facet** _M_facets;
487 size_t _M_facets_size;
488 const facet** _M_caches;
490 static const locale::id* const _S_id_ctype[];
491 static const locale::id* const _S_id_numeric[];
492 static const locale::id* const _S_id_collate[];
493 static const locale::id* const _S_id_time[];
494 static const locale::id* const _S_id_monetary[];
495 static const locale::id* const _S_id_messages[];
496 static const locale::id* const* const _S_facet_categories[];
499 _M_add_reference() throw()
500 { __gnu_cxx::__atomic_add_dispatch(&_M_refcount, 1); }
503 _M_remove_reference() throw()
505 if (__gnu_cxx::__exchange_and_add_dispatch(&_M_refcount, -1) == 1)
514 _Impl(const _Impl&, size_t);
515 _Impl(const char*, size_t);
516 _Impl(size_t) throw();
520 _Impl(const _Impl&); // Not defined.
523 operator=(const _Impl&); // Not defined.
530 // We must actually compare all the _M_names: can be all equal!
531 for (size_t __i = 0; __ret && __i < _S_categories_size - 1; ++__i)
532 __ret = __builtin_strcmp(_M_names[__i], _M_names[__i + 1]) == 0;
537 _M_replace_categories(const _Impl*, category);
540 _M_replace_category(const _Impl*, const locale::id* const*);
543 _M_replace_facet(const _Impl*, const locale::id*);
546 _M_install_facet(const locale::id*, const facet*);
548 template<typename _Facet>
550 _M_init_facet(_Facet* __facet)
551 { _M_install_facet(&_Facet::id, __facet); }
554 _M_install_cache(const facet*, size_t);
559 * @brief Test for the presence of a facet.
561 * has_facet tests the locale argument for the presence of the facet type
562 * provided as the template parameter. Facets derived from the facet
563 * parameter will also return true.
565 * @param Facet The facet type to test the presence of.
566 * @param locale The locale to test.
567 * @return true if locale contains a facet of type Facet, else false.
569 template<typename _Facet>
571 has_facet(const locale& __loc) throw();
574 * @brief Return a facet.
576 * use_facet looks for and returns a reference to a facet of type Facet
577 * where Facet is the template parameter. If has_facet(locale) is true,
578 * there is a suitable facet to return. It throws std::bad_cast if the
579 * locale doesn't contain a facet of type Facet.
581 * @param Facet The facet type to access.
582 * @param locale The locale to use.
583 * @return Reference to facet of type Facet.
584 * @throw std::bad_cast if locale doesn't contain a facet of type Facet.
586 template<typename _Facet>
588 use_facet(const locale& __loc);
592 * @brief Facet for localized string comparison.
594 * This facet encapsulates the code to compare strings in a localized
597 * The collate template uses protected virtual functions to provide
598 * the actual results. The public accessors forward the call to
599 * the virtual functions. These virtual functions are hooks for
600 * developers to implement the behavior they require from the
603 template<typename _CharT>
604 class collate : public locale::facet
610 typedef _CharT char_type;
611 typedef basic_string<_CharT> string_type;
615 // Underlying "C" library locale information saved from
616 // initialization, needed by collate_byname as well.
617 __c_locale _M_c_locale_collate;
620 /// Numpunct facet id.
621 static locale::id id;
624 * @brief Constructor performs initialization.
626 * This is the constructor provided by the standard.
628 * @param refs Passed to the base facet class.
631 collate(size_t __refs = 0)
632 : facet(__refs), _M_c_locale_collate(_S_get_c_locale())
636 * @brief Internal constructor. Not for general use.
638 * This is a constructor for use by the library itself to set up new
641 * @param cloc The "C" locale.
642 * @param refs Passed to the base facet class.
645 collate(__c_locale __cloc, size_t __refs = 0)
646 : facet(__refs), _M_c_locale_collate(_S_clone_c_locale(__cloc))
650 * @brief Compare two strings.
652 * This function compares two strings and returns the result by calling
653 * collate::do_compare().
655 * @param lo1 Start of string 1.
656 * @param hi1 End of string 1.
657 * @param lo2 Start of string 2.
658 * @param hi2 End of string 2.
659 * @return 1 if string1 > string2, -1 if string1 < string2, else 0.
662 compare(const _CharT* __lo1, const _CharT* __hi1,
663 const _CharT* __lo2, const _CharT* __hi2) const
664 { return this->do_compare(__lo1, __hi1, __lo2, __hi2); }
667 * @brief Transform string to comparable form.
669 * This function is a wrapper for strxfrm functionality. It takes the
670 * input string and returns a modified string that can be directly
671 * compared to other transformed strings. In the "C" locale, this
672 * function just returns a copy of the input string. In some other
673 * locales, it may replace two chars with one, change a char for
674 * another, etc. It does so by returning collate::do_transform().
676 * @param lo Start of string.
677 * @param hi End of string.
678 * @return Transformed string_type.
681 transform(const _CharT* __lo, const _CharT* __hi) const
682 { return this->do_transform(__lo, __hi); }
685 * @brief Return hash of a string.
687 * This function computes and returns a hash on the input string. It
688 * does so by returning collate::do_hash().
690 * @param lo Start of string.
691 * @param hi End of string.
692 * @return Hash value.
695 hash(const _CharT* __lo, const _CharT* __hi) const
696 { return this->do_hash(__lo, __hi); }
698 // Used to abstract out _CharT bits in virtual member functions, below.
700 _M_compare(const _CharT*, const _CharT*) const;
703 _M_transform(_CharT*, const _CharT*, size_t) const;
709 { _S_destroy_c_locale(_M_c_locale_collate); }
712 * @brief Compare two strings.
714 * This function is a hook for derived classes to change the value
715 * returned. @see compare().
717 * @param lo1 Start of string 1.
718 * @param hi1 End of string 1.
719 * @param lo2 Start of string 2.
720 * @param hi2 End of string 2.
721 * @return 1 if string1 > string2, -1 if string1 < string2, else 0.
724 do_compare(const _CharT* __lo1, const _CharT* __hi1,
725 const _CharT* __lo2, const _CharT* __hi2) const;
728 * @brief Transform string to comparable form.
730 * This function is a hook for derived classes to change the value
733 * @param lo1 Start of string 1.
734 * @param hi1 End of string 1.
735 * @param lo2 Start of string 2.
736 * @param hi2 End of string 2.
737 * @return 1 if string1 > string2, -1 if string1 < string2, else 0.
740 do_transform(const _CharT* __lo, const _CharT* __hi) const;
743 * @brief Return hash of a string.
745 * This function computes and returns a hash on the input string. This
746 * function is a hook for derived classes to change the value returned.
748 * @param lo Start of string.
749 * @param hi End of string.
750 * @return Hash value.
753 do_hash(const _CharT* __lo, const _CharT* __hi) const;
756 template<typename _CharT>
757 locale::id collate<_CharT>::id;
762 collate<char>::_M_compare(const char*, const char*) const;
766 collate<char>::_M_transform(char*, const char*, size_t) const;
768 #ifdef _GLIBCXX_USE_WCHAR_T
771 collate<wchar_t>::_M_compare(const wchar_t*, const wchar_t*) const;
775 collate<wchar_t>::_M_transform(wchar_t*, const wchar_t*, size_t) const;
778 /// class collate_byname [22.2.4.2].
779 template<typename _CharT>
780 class collate_byname : public collate<_CharT>
785 typedef _CharT char_type;
786 typedef basic_string<_CharT> string_type;
790 collate_byname(const char* __s, size_t __refs = 0)
791 : collate<_CharT>(__refs)
793 if (__builtin_strcmp(__s, "C") != 0
794 && __builtin_strcmp(__s, "POSIX") != 0)
796 this->_S_destroy_c_locale(this->_M_c_locale_collate);
797 this->_S_create_c_locale(this->_M_c_locale_collate, __s);
803 ~collate_byname() { }
806 _GLIBCXX_END_NAMESPACE
808 #ifndef _GLIBCXX_EXPORT_TEMPLATE
809 # include <bits/locale_classes.tcc>