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 @a __f
172 * is added to @a __other, replacing an existing facet of type
173 * Facet if there is one. If @a __f is null, this locale is a
174 * copy of @a __other.
176 * @param __other The locale to copy.
177 * @param __f The facet to add in.
179 template<typename _Facet>
180 locale(const locale& __other, _Facet* __f);
182 /// Locale destructor.
186 * @brief Assignment operator.
188 * Set this locale to be a copy of @a other.
190 * @param __other The locale to copy.
191 * @return A reference to this locale.
194 operator=(const locale& __other) throw();
197 * @brief Construct locale with another facet.
199 * Constructs and returns a new copy of this locale. Adds or replaces an
200 * existing facet of type Facet from the locale @a other into the new
203 * @tparam _Facet The facet type to copy from other
204 * @param __other The locale to copy from.
205 * @return Newly constructed locale.
206 * @throw std::runtime_error if __other has no facet of type _Facet.
208 template<typename _Facet>
210 combine(const locale& __other) const;
212 // Locale operations:
214 * @brief Return locale name.
215 * @return Locale name or "*" if unnamed.
221 * @brief Locale equality.
223 * @param __other The locale to compare against.
224 * @return True if other and this refer to the same locale instance, are
225 * copies, or have the same name. False otherwise.
228 operator==(const locale& __other) const throw();
231 * @brief Locale inequality.
233 * @param __other The locale to compare against.
234 * @return ! (*this == __other)
237 operator!=(const locale& __other) const throw()
238 { return !(this->operator==(__other)); }
241 * @brief Compare two strings according to collate.
243 * Template operator to compare two strings using the compare function of
244 * the collate facet in this locale. One use is to provide the locale to
245 * the sort function. For example, a vector v of strings could be sorted
246 * according to locale loc by doing:
248 * std::sort(v.begin(), v.end(), loc);
251 * @param __s1 First string to compare.
252 * @param __s2 Second string to compare.
253 * @return True if collate<_Char> facet compares __s1 < __s2, else false.
255 template<typename _Char, typename _Traits, typename _Alloc>
257 operator()(const basic_string<_Char, _Traits, _Alloc>& __s1,
258 const basic_string<_Char, _Traits, _Alloc>& __s2) const;
260 // Global locale objects:
262 * @brief Set global locale
264 * This function sets the global locale to the argument and returns a
265 * copy of the previous global locale. If the argument has a name, it
266 * will also call std::setlocale(LC_ALL, loc.name()).
268 * @param __loc The new locale to make global.
269 * @return Copy of the old global locale.
272 global(const locale& __loc);
275 * @brief Return reference to the C locale.
281 // The (shared) implementation
284 // The "C" reference locale
285 static _Impl* _S_classic;
287 // Current global locale
288 static _Impl* _S_global;
290 // Names of underlying locale categories.
291 // NB: locale::global() has to know how to modify all the
292 // underlying categories, not just the ones required by the C++
294 static const char* const* const _S_categories;
296 // Number of standard categories. For C++, these categories are
297 // collate, ctype, monetary, numeric, time, and messages. These
298 // directly correspond to ISO C99 macros LC_COLLATE, LC_CTYPE,
299 // LC_MONETARY, LC_NUMERIC, and LC_TIME. In addition, POSIX (IEEE
300 // 1003.1-2001) specifies LC_MESSAGES.
301 // In addition to the standard categories, the underlying
302 // operating system is allowed to define extra LC_*
303 // macros. For GNU systems, the following are also valid:
304 // LC_PAPER, LC_NAME, LC_ADDRESS, LC_TELEPHONE, LC_MEASUREMENT,
305 // and LC_IDENTIFICATION.
306 enum { _S_categories_size = 6 + _GLIBCXX_NUM_CATEGORIES };
309 static __gthread_once_t _S_once;
313 locale(_Impl*) throw();
319 _S_initialize_once() throw();
322 _S_normalize_category(category);
325 _M_coalesce(const locale& __base, const locale& __add, category __cat);
329 // 22.1.1.1.2 Class locale::facet
331 * @brief Localization functionality base class.
334 * The facet class is the base class for a localization feature, such as
335 * money, time, and number printing. It provides common support for facets
336 * and reference management.
338 * Facets may not be copied or assigned.
344 friend class locale::_Impl;
346 mutable _Atomic_word _M_refcount;
348 // Contains data from the underlying "C" library for the classic locale.
349 static __c_locale _S_c_locale;
351 // String literal for the name of the classic locale.
352 static const char _S_c_name[2];
355 static __gthread_once_t _S_once;
359 _S_initialize_once();
363 * @brief Facet constructor.
365 * This is the constructor provided by the standard. If refs is 0, the
366 * facet is destroyed when the last referencing locale is destroyed.
367 * Otherwise the facet will never be destroyed.
369 * @param __refs The initial value for reference count.
372 facet(size_t __refs = 0) throw() : _M_refcount(__refs ? 1 : 0)
375 /// Facet destructor.
380 _S_create_c_locale(__c_locale& __cloc, const char* __s,
381 __c_locale __old = 0);
384 _S_clone_c_locale(__c_locale& __cloc) throw();
387 _S_destroy_c_locale(__c_locale& __cloc);
390 _S_lc_ctype_c_locale(__c_locale __cloc, const char* __s);
392 // Returns data from the underlying "C" library data for the
397 _GLIBCXX_CONST static const char*
398 _S_get_c_name() throw();
402 _M_add_reference() const throw()
403 { __gnu_cxx::__atomic_add_dispatch(&_M_refcount, 1); }
406 _M_remove_reference() const throw()
408 // Be race-detector-friendly. For more info see bits/c++config.
409 _GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_M_refcount);
410 if (__gnu_cxx::__exchange_and_add_dispatch(&_M_refcount, -1) == 1)
412 _GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_M_refcount);
420 facet(const facet&); // Not defined.
423 operator=(const facet&); // Not defined.
427 // 22.1.1.1.3 Class locale::id
429 * @brief Facet ID class.
432 * The ID class provides facets with an index used to identify them.
433 * Every facet class must define a public static member locale::id, or be
434 * derived from a facet that provides this member, otherwise the facet
435 * cannot be used in a locale. The locale::id ensures that each class
436 * type gets a unique identifier.
442 friend class locale::_Impl;
444 template<typename _Facet>
446 use_facet(const locale&);
448 template<typename _Facet>
450 has_facet(const locale&) throw();
452 // NB: There is no accessor for _M_index because it may be used
453 // before the constructor is run; the effect of calling a member
454 // function (even an inline) would be undefined.
455 mutable size_t _M_index;
457 // Last id number assigned.
458 static _Atomic_word _S_refcount;
461 operator=(const id&); // Not defined.
463 id(const id&); // Not defined.
466 // NB: This class is always a static data member, and thus can be
467 // counted on to be zero-initialized.
472 _M_id() const throw();
476 // Implementation object for locale.
482 friend class locale::facet;
484 template<typename _Facet>
486 has_facet(const locale&) throw();
488 template<typename _Facet>
490 use_facet(const locale&);
492 template<typename _Cache>
493 friend struct __use_cache;
497 _Atomic_word _M_refcount;
498 const facet** _M_facets;
499 size_t _M_facets_size;
500 const facet** _M_caches;
502 static const locale::id* const _S_id_ctype[];
503 static const locale::id* const _S_id_numeric[];
504 static const locale::id* const _S_id_collate[];
505 static const locale::id* const _S_id_time[];
506 static const locale::id* const _S_id_monetary[];
507 static const locale::id* const _S_id_messages[];
508 static const locale::id* const* const _S_facet_categories[];
511 _M_add_reference() throw()
512 { __gnu_cxx::__atomic_add_dispatch(&_M_refcount, 1); }
515 _M_remove_reference() throw()
517 // Be race-detector-friendly. For more info see bits/c++config.
518 _GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_M_refcount);
519 if (__gnu_cxx::__exchange_and_add_dispatch(&_M_refcount, -1) == 1)
521 _GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_M_refcount);
529 _Impl(const _Impl&, size_t);
530 _Impl(const char*, size_t);
531 _Impl(size_t) throw();
535 _Impl(const _Impl&); // Not defined.
538 operator=(const _Impl&); // Not defined.
545 // We must actually compare all the _M_names: can be all equal!
546 for (size_t __i = 0; __ret && __i < _S_categories_size - 1; ++__i)
547 __ret = __builtin_strcmp(_M_names[__i], _M_names[__i + 1]) == 0;
552 _M_replace_categories(const _Impl*, category);
555 _M_replace_category(const _Impl*, const locale::id* const*);
558 _M_replace_facet(const _Impl*, const locale::id*);
561 _M_install_facet(const locale::id*, const facet*);
563 template<typename _Facet>
565 _M_init_facet(_Facet* __facet)
566 { _M_install_facet(&_Facet::id, __facet); }
569 _M_install_cache(const facet*, size_t);
574 * @brief Facet for localized string comparison.
576 * This facet encapsulates the code to compare strings in a localized
579 * The collate template uses protected virtual functions to provide
580 * the actual results. The public accessors forward the call to
581 * the virtual functions. These virtual functions are hooks for
582 * developers to implement the behavior they require from the
585 template<typename _CharT>
586 class collate : public locale::facet
592 typedef _CharT char_type;
593 typedef basic_string<_CharT> string_type;
597 // Underlying "C" library locale information saved from
598 // initialization, needed by collate_byname as well.
599 __c_locale _M_c_locale_collate;
602 /// Numpunct facet id.
603 static locale::id id;
606 * @brief Constructor performs initialization.
608 * This is the constructor provided by the standard.
610 * @param __refs Passed to the base facet class.
613 collate(size_t __refs = 0)
614 : facet(__refs), _M_c_locale_collate(_S_get_c_locale())
618 * @brief Internal constructor. Not for general use.
620 * This is a constructor for use by the library itself to set up new
623 * @param __cloc The C locale.
624 * @param __refs Passed to the base facet class.
627 collate(__c_locale __cloc, size_t __refs = 0)
628 : facet(__refs), _M_c_locale_collate(_S_clone_c_locale(__cloc))
632 * @brief Compare two strings.
634 * This function compares two strings and returns the result by calling
635 * collate::do_compare().
637 * @param __lo1 Start of string 1.
638 * @param __hi1 End of string 1.
639 * @param __lo2 Start of string 2.
640 * @param __hi2 End of string 2.
641 * @return 1 if string1 > string2, -1 if string1 < string2, else 0.
644 compare(const _CharT* __lo1, const _CharT* __hi1,
645 const _CharT* __lo2, const _CharT* __hi2) const
646 { return this->do_compare(__lo1, __hi1, __lo2, __hi2); }
649 * @brief Transform string to comparable form.
651 * This function is a wrapper for strxfrm functionality. It takes the
652 * input string and returns a modified string that can be directly
653 * compared to other transformed strings. In the C locale, this
654 * function just returns a copy of the input string. In some other
655 * locales, it may replace two chars with one, change a char for
656 * another, etc. It does so by returning collate::do_transform().
658 * @param __lo Start of string.
659 * @param __hi End of string.
660 * @return Transformed string_type.
663 transform(const _CharT* __lo, const _CharT* __hi) const
664 { return this->do_transform(__lo, __hi); }
667 * @brief Return hash of a string.
669 * This function computes and returns a hash on the input string. It
670 * does so by returning collate::do_hash().
672 * @param __lo Start of string.
673 * @param __hi End of string.
674 * @return Hash value.
677 hash(const _CharT* __lo, const _CharT* __hi) const
678 { return this->do_hash(__lo, __hi); }
680 // Used to abstract out _CharT bits in virtual member functions, below.
682 _M_compare(const _CharT*, const _CharT*) const throw();
685 _M_transform(_CharT*, const _CharT*, size_t) const throw();
691 { _S_destroy_c_locale(_M_c_locale_collate); }
694 * @brief Compare two strings.
696 * This function is a hook for derived classes to change the value
697 * returned. @see compare().
699 * @param __lo1 Start of string 1.
700 * @param __hi1 End of string 1.
701 * @param __lo2 Start of string 2.
702 * @param __hi2 End of string 2.
703 * @return 1 if string1 > string2, -1 if string1 < string2, else 0.
706 do_compare(const _CharT* __lo1, const _CharT* __hi1,
707 const _CharT* __lo2, const _CharT* __hi2) const;
710 * @brief Transform string to comparable form.
712 * This function is a hook for derived classes to change the value
717 * @return transformed string.
720 do_transform(const _CharT* __lo, const _CharT* __hi) const;
723 * @brief Return hash of a string.
725 * This function computes and returns a hash on the input string. This
726 * function is a hook for derived classes to change the value returned.
728 * @param __lo Start of string.
729 * @param __hi End of string.
730 * @return Hash value.
733 do_hash(const _CharT* __lo, const _CharT* __hi) const;
736 template<typename _CharT>
737 locale::id collate<_CharT>::id;
742 collate<char>::_M_compare(const char*, const char*) const throw();
746 collate<char>::_M_transform(char*, const char*, size_t) const throw();
748 #ifdef _GLIBCXX_USE_WCHAR_T
751 collate<wchar_t>::_M_compare(const wchar_t*, const wchar_t*) const throw();
755 collate<wchar_t>::_M_transform(wchar_t*, const wchar_t*, size_t) const throw();
758 /// class collate_byname [22.2.4.2].
759 template<typename _CharT>
760 class collate_byname : public collate<_CharT>
765 typedef _CharT char_type;
766 typedef basic_string<_CharT> string_type;
770 collate_byname(const char* __s, size_t __refs = 0)
771 : collate<_CharT>(__refs)
773 if (__builtin_strcmp(__s, "C") != 0
774 && __builtin_strcmp(__s, "POSIX") != 0)
776 this->_S_destroy_c_locale(this->_M_c_locale_collate);
777 this->_S_create_c_locale(this->_M_c_locale_collate, __s);
783 ~collate_byname() { }
786 _GLIBCXX_END_NAMESPACE_VERSION
789 # include <bits/locale_classes.tcc>