# locale_classes.h

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    00001 // Locale support -*- C++ -*-
    00002
    00003 // Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004
    00004 // Free Software Foundation, Inc.
    00005 //
    00006 // This file is part of the GNU ISO C++ Library.  This library is free
    00007 // software; you can redistribute it and/or modify it under the
    00008 // terms of the GNU General Public License as published by the
    00009 // Free Software Foundation; either version 2, or (at your option)
    00010 // any later version.
    00011
    00012 // This library is distributed in the hope that it will be useful,
    00013 // but WITHOUT ANY WARRANTY; without even the implied warranty of
    00014 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    00015 // GNU General Public License for more details.
    00016
    00017 // You should have received a copy of the GNU General Public License along
    00018 // with this library; see the file COPYING.  If not, write to the Free
    00019 // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
    00020 // USA.
    00021
    00022 // As a special exception, you may use this file as part of a free software
    00023 // library without restriction.  Specifically, if other files instantiate
    00024 // templates or use macros or inline functions from this file, or you compile
    00025 // this file and link it with other files to produce an executable, this
    00026 // file does not by itself cause the resulting executable to be covered by
    00027 // the GNU General Public License.  This exception does not however
    00028 // invalidate any other reasons why the executable file might be covered by
    00029 // the GNU General Public License.
    00030
    00031 //
    00032 // ISO C++ 14882: 22.1  Locales
    00033 //
    00034
    00035 /** @file locale_classes.h
    00036  *  This is an internal header file, included by other library headers.
    00037  *  You should not attempt to use it directly.
    00038  */
    00039
    00040 #ifndef _LOCALE_CLASSES_H
    00041 #define _LOCALE_CLASSES_H 1
    00042
    00043 #pragma GCC system_header
    00044
    00045 #include <bits/localefwd.h>
    00046 #include <cstring>      // For strcmp.
    00047 #include <string>
    00048 #include <bits/atomicity.h>
    00049 #include <bits/gthr.h>
    00050
    00051 namespace std
    00052 {
    00053   // 22.1.1 Class locale
    00054   /**
    00055    *  @brief  Container class for localization functionality.
    00056    *
    00057    *  The locale class is first a class wrapper for C library locales.  It is
    00058    *  also an extensible container for user-defined localization.  A locale is
    00059    *  a collection of facets that implement various localization features such
    00060    *  as money, time, and number printing.
    00061    *
    00062    *  Constructing C++ locales does not change the C library locale.
    00063    *
    00064    *  This library supports efficient construction and copying of locales
    00065    *  through a reference counting implementation of the locale class.
    00066   */
    00067   class locale
    00068   {
    00069   public:
    00070     // Types:
    00071     /// Definition of locale::category.
    00072     typedef int category;
    00073
    00074     // Forward decls and friends:
    00075     class facet;
    00076     class id;
    00077     class _Impl;
    00078
    00079     friend class facet;
    00080     friend class _Impl;
    00081
    00082     template<typename _Facet>
    00083       friend bool
    00084       has_facet(const locale&) throw();
    00085
    00086     template<typename _Facet>
    00087       friend const _Facet&
    00088       use_facet(const locale&);
    00089
    00090     template<typename _Cache>
    00091       friend struct __use_cache;
    00092
    00093     //@{
    00094     /**
    00095      *  @brief  Category values.
    00096      *
    00097      *  The standard category values are none, ctype, numeric, collate, time,
    00098      *  monetary, and messages.  They form a bitmask that supports union and
    00099      *  intersection.  The category all is the union of these values.
    00100      *
    00101      *  @if maint
    00102      *  NB: Order must match _S_facet_categories definition in locale.cc
    00103      *  @endif
    00104     */
    00105     static const category none      = 0;
    00106     static const category ctype     = 1L << 0;
    00107     static const category numeric   = 1L << 1;
    00108     static const category collate   = 1L << 2;
    00109     static const category time      = 1L << 3;
    00110     static const category monetary  = 1L << 4;
    00111     static const category messages  = 1L << 5;
    00112     static const category all       = (ctype | numeric | collate |
    00113                        time  | monetary | messages);
    00114     //@}
    00115
    00116     // Construct/copy/destroy:
    00117
    00118     /**
    00119      *  @brief  Default constructor.
    00120      *
    00121      *  Constructs a copy of the global locale.  If no locale has been
    00122      *  explicitly set, this is the "C" locale.
    00123     */
    00124     locale() throw();
    00125
    00126     /**
    00127      *  @brief  Copy constructor.
    00128      *
    00129      *  Constructs a copy of @a other.
    00130      *
    00131      *  @param  other  The locale to copy.
    00132     */
    00133     locale(const locale& __other) throw();
    00134
    00135     /**
    00136      *  @brief  Named locale constructor.
    00137      *
    00138      *  Constructs a copy of the named C library locale.
    00139      *
    00140      *  @param  s  Name of the locale to construct.
    00141      *  @throw  std::runtime_error if s is null or an undefined locale.
    00142     */
    00143     explicit
    00144     locale(const char* __s);
    00145
    00146     /**
    00147      *  @brief  Construct locale with facets from another locale.
    00148      *
    00149      *  Constructs a copy of the locale @a base.  The facets specified by @a
    00150      *  cat are replaced with those from the locale named by @a s.  If base is
    00151      *  named, this locale instance will also be named.
    00152      *
    00153      *  @param  base  The locale to copy.
    00154      *  @param  s  Name of the locale to use facets from.
    00155      *  @param  cat  Set of categories defining the facets to use from s.
    00156      *  @throw  std::runtime_error if s is null or an undefined locale.
    00157     */
    00158     locale(const locale& __base, const char* __s, category __cat);
    00159
    00160     /**
    00161      *  @brief  Construct locale with facets from another locale.
    00162      *
    00163      *  Constructs a copy of the locale @a base.  The facets specified by @a
    00164      *  cat are replaced with those from the locale @a add.  If @a base and @a
    00165      *  add are named, this locale instance will also be named.
    00166      *
    00167      *  @param  base  The locale to copy.
    00168      *  @param  add  The locale to use facets from.
    00169      *  @param  cat  Set of categories defining the facets to use from add.
    00170     */
    00171     locale(const locale& __base, const locale& __add, category __cat);
    00172
    00173     /**
    00174      *  @brief  Construct locale with another facet.
    00175      *
    00176      *  Constructs a copy of the locale @a other.  The facet @f is added to
    00177      *  @other, replacing an existing facet of type Facet if there is one.  If
    00178      *  @f is null, this locale is a copy of @a other.
    00179      *
    00180      *  @param  other  The locale to copy.
    00181      *  @param  f  The facet to add in.
    00182     */
    00183     template<typename _Facet>
    00184       locale(const locale& __other, _Facet* __f);
    00185
    00186     /// Locale destructor.
    00187     ~locale() throw();
    00188
    00189     /**
    00190      *  @brief  Assignment operator.
    00191      *
    00192      *  Set this locale to be a copy of @a other.
    00193      *
    00194      *  @param  other  The locale to copy.
    00195      *  @return  A reference to this locale.
    00196     */
    00197     const locale&
    00198     operator=(const locale& __other) throw();
    00199
    00200     /**
    00201      *  @brief  Construct locale with another facet.
    00202      *
    00203      *  Constructs and returns a new copy of this locale.  Adds or replaces an
    00204      *  existing facet of type Facet from the locale @a other into the new
    00205      *  locale.
    00206      *
    00207      *  @param  Facet  The facet type to copy from other
    00208      *  @param  other  The locale to copy from.
    00209      *  @return  Newly constructed locale.
    00210      *  @throw  std::runtime_error if other has no facet of type Facet.
    00211     */
    00212     template<typename _Facet>
    00213       locale
    00214       combine(const locale& __other) const;
    00215
    00216     // Locale operations:
    00217     /**
    00218      *  @brief  Return locale name.
    00219      *  @return  Locale name or "*" if unnamed.
    00220     */
    00221     string
    00222     name() const;
    00223
    00224     /**
    00225      *  @brief  Locale equality.
    00226      *
    00227      *  @param  other  The locale to compare against.
    00228      *  @return  True if other and this refer to the same locale instance, are
    00229      *       copies, or have the same name.  False otherwise.
    00230     */
    00231     bool
    00232     operator==(const locale& __other) const throw ();
    00233
    00234     /**
    00235      *  @brief  Locale inequality.
    00236      *
    00237      *  @param  other  The locale to compare against.
    00238      *  @return  ! (*this == other)
    00239     */
    00240     inline bool
    00241     operator!=(const locale& __other) const throw ()
    00242     { return !(this->operator==(__other));  }
    00243
    00244     /**
    00245      *  @brief  Compare two strings according to collate.
    00246      *
    00247      *  Template operator to compare two strings using the compare function of
    00248      *  the collate facet in this locale.  One use is to provide the locale to
    00249      *  the sort function.  For example, a vector v of strings could be sorted
    00250      *  according to locale loc by doing:
    00251      *  @code
    00252      *  std::sort(v.begin(), v.end(), loc);
    00253      *  @endcode
    00254      *
    00255      *  @param  s1  First string to compare.
    00256      *  @param  s2  Second string to compare.
    00257      *  @return  True if collate<Char> facet compares s1 < s2, else false.
    00258     */
    00259     template<typename _Char, typename _Traits, typename _Alloc>
    00260       bool
    00261       operator()(const basic_string<_Char, _Traits, _Alloc>& __s1,
    00262          const basic_string<_Char, _Traits, _Alloc>& __s2) const;
    00263
    00264     // Global locale objects:
    00265     /**
    00266      *  @brief  Set global locale
    00267      *
    00268      *  This function sets the global locale to the argument and returns a
    00269      *  copy of the previous global locale.  If the argument has a name, it
    00270      *  will also call std::setlocale(LC_ALL, loc.name()).
    00271      *
    00272      *  @param  locale  The new locale to make global.
    00273      *  @return  Copy of the old global locale.
    00274     */
    00275     static locale
    00276     global(const locale&);
    00277
    00278     /**
    00279      *  @brief  Return reference to the "C" locale.
    00280     */
    00281     static const locale&
    00282     classic();
    00283
    00284   private:
    00285     // The (shared) implementation
    00286     _Impl*      _M_impl;
    00287
    00288     // The "C" reference locale
    00289     static _Impl*       _S_classic;
    00290
    00291     // Current global locale
    00292     static _Impl*   _S_global;
    00293
    00294     // Names of underlying locale categories.
    00295     // NB: locale::global() has to know how to modify all the
    00296     // underlying categories, not just the ones required by the C++
    00297     // standard.
    00298     static const char* const* const _S_categories;
    00299
    00300     // Number of standard categories. For C++, these categories are
    00301     // collate, ctype, monetary, numeric, time, and messages. These
    00302     // directly correspond to ISO C99 macros LC_COLLATE, LC_CTYPE,
    00303     // LC_MONETARY, LC_NUMERIC, and LC_TIME. In addition, POSIX (IEEE
    00304     // 1003.1-2001) specifies LC_MESSAGES.
    00305     // In addition to the standard categories, the underlying
    00306     // operating system is allowed to define extra LC_*
    00307     // macros. For GNU systems, the following are also valid:
    00308     // LC_PAPER, LC_NAME, LC_ADDRESS, LC_TELEPHONE, LC_MEASUREMENT,
    00309     // and LC_IDENTIFICATION.
    00310     static const size_t _S_categories_size = 6 + _GLIBCXX_NUM_CATEGORIES;
    00311
    00312 #ifdef __GTHREADS
    00313     static __gthread_once_t _S_once;
    00314 #endif
    00315
    00316     explicit
    00317     locale(_Impl*) throw();
    00318
    00319     static void
    00320     _S_initialize();
    00321
    00322     static void
    00323     _S_initialize_once();
    00324
    00325     static category
    00326     _S_normalize_category(category);
    00327
    00328     void
    00329     _M_coalesce(const locale& __base, const locale& __add, category __cat);
    00330   };
    00331
    00332
    00333   // 22.1.1.1.2  Class locale::facet
    00334   /**
    00335    *  @brief  Localization functionality base class.
    00336    *
    00337    *  The facet class is the base class for a localization feature, such as
    00338    *  money, time, and number printing.  It provides common support for facets
    00339    *  and reference management.
    00340    *
    00341    *  Facets may not be copied or assigned.
    00342   */
    00343   class locale::facet
    00344   {
    00345   private:
    00346     friend class locale;
    00347     friend class locale::_Impl;
    00348
    00349     mutable _Atomic_word        _M_refcount;
    00350
    00351     // Contains data from the underlying "C" library for the classic locale.
    00352     static __c_locale                   _S_c_locale;
    00353
    00354     // String literal for the name of the classic locale.
    00355     static const char           _S_c_name[2];
    00356
    00357 #ifdef __GTHREADS
    00358     static __gthread_once_t     _S_once;
    00359 #endif
    00360
    00361     static void
    00362     _S_initialize_once();
    00363
    00364   protected:
    00365     /**
    00366      *  @brief  Facet constructor.
    00367      *
    00368      *  This is the constructor provided by the standard.  If refs is 0, the
    00369      *  facet is destroyed when the last referencing locale is destroyed.
    00370      *  Otherwise the facet will never be destroyed.
    00371      *
    00372      *  @param refs  The initial value for reference count.
    00373     */
    00374     explicit
    00375     facet(size_t __refs = 0) throw() : _M_refcount(__refs ? 1 : 0)
    00376     { }
    00377
    00378     /// Facet destructor.
    00379     virtual
    00380     ~facet();
    00381
    00382     static void
    00383     _S_create_c_locale(__c_locale& __cloc, const char* __s,
    00384                __c_locale __old = 0);
    00385
    00386     static __c_locale
    00387     _S_clone_c_locale(__c_locale& __cloc);
    00388
    00389     static void
    00390     _S_destroy_c_locale(__c_locale& __cloc);
    00391
    00392     // Returns data from the underlying "C" library data for the
    00393     // classic locale.
    00394     static __c_locale
    00395     _S_get_c_locale();
    00396
    00397     static const char*
    00398     _S_get_c_name();
    00399
    00400   private:
    00401     inline void
    00402     _M_add_reference() const throw()
    00403     { __gnu_cxx::__atomic_add(&_M_refcount, 1); }
    00404
    00405     inline void
    00406     _M_remove_reference() const throw()
    00407     {
    00408       if (__gnu_cxx::__exchange_and_add(&_M_refcount, -1) == 1)
    00409     {
    00410       try
    00411         { delete this; }
    00412       catch (...)
    00413         { }
    00414     }
    00415     }
    00416
    00417     facet(const facet&);  // Not defined.
    00418
    00419     facet&
    00420     operator=(const facet&);  // Not defined.
    00421   };
    00422
    00423
    00424   // 22.1.1.1.3 Class locale::id
    00425   /**
    00426    *  @brief  Facet ID class.
    00427    *
    00428    *  The ID class provides facets with an index used to identify them.
    00429    *  Every facet class must define a public static member locale::id, or be
    00430    *  derived from a facet that provides this member, otherwise the facet
    00431    *  cannot be used in a locale.  The locale::id ensures that each class
    00432    *  type gets a unique identifier.
    00433   */
    00434   class locale::id
    00435   {
    00436   private:
    00437     friend class locale;
    00438     friend class locale::_Impl;
    00439
    00440     template<typename _Facet>
    00441       friend const _Facet&
    00442       use_facet(const locale&);
    00443
    00444     template<typename _Facet>
    00445       friend bool
    00446       has_facet(const locale&) throw ();
    00447
    00448     // NB: There is no accessor for _M_index because it may be used
    00449     // before the constructor is run; the effect of calling a member
    00450     // function (even an inline) would be undefined.
    00451     mutable size_t      _M_index;
    00452
    00453     // Last id number assigned.
    00454     static _Atomic_word     _S_refcount;
    00455
    00456     void
    00457     operator=(const id&);  // Not defined.
    00458
    00459     id(const id&);  // Not defined.
    00460
    00461   public:
    00462     // NB: This class is always a static data member, and thus can be
    00463     // counted on to be zero-initialized.
    00464     /// Constructor.
    00465     id() { }
    00466
    00467     size_t
    00468     _M_id() const;
    00469   };
    00470
    00471
    00472   // Implementation object for locale.
    00473   class locale::_Impl
    00474   {
    00475   public:
    00476     // Friends.
    00477     friend class locale;
    00478     friend class locale::facet;
    00479
    00480     template<typename _Facet>
    00481       friend bool
    00482       has_facet(const locale&) throw();
    00483
    00484     template<typename _Facet>
    00485       friend const _Facet&
    00486       use_facet(const locale&);
    00487
    00488     template<typename _Cache>
    00489       friend struct __use_cache;
    00490
    00491   private:
    00492     // Data Members.
    00493     _Atomic_word            _M_refcount;
    00494     const facet**           _M_facets;
    00495     size_t              _M_facets_size;
    00496     const facet**           _M_caches;
    00497     char**              _M_names;
    00498     static const locale::id* const  _S_id_ctype[];
    00499     static const locale::id* const  _S_id_numeric[];
    00500     static const locale::id* const  _S_id_collate[];
    00501     static const locale::id* const  _S_id_time[];
    00502     static const locale::id* const  _S_id_monetary[];
    00503     static const locale::id* const  _S_id_messages[];
    00504     static const locale::id* const* const _S_facet_categories[];
    00505
    00506     inline void
    00507     _M_add_reference() throw()
    00508     { __gnu_cxx::__atomic_add(&_M_refcount, 1); }
    00509
    00510     inline void
    00511     _M_remove_reference() throw()
    00512     {
    00513       if (__gnu_cxx::__exchange_and_add(&_M_refcount, -1) == 1)
    00514     {
    00515       try
    00516         { delete this; }
    00517       catch(...)
    00518         { }
    00519     }
    00520     }
    00521
    00522     _Impl(const _Impl&, size_t);
    00523     _Impl(const char*, size_t);
    00524     _Impl(size_t) throw();
    00525
    00526    ~_Impl() throw();
    00527
    00528     _Impl(const _Impl&);  // Not defined.
    00529
    00530     void
    00531     operator=(const _Impl&);  // Not defined.
    00532
    00533     inline bool
    00534     _M_check_same_name()
    00535     {
    00536       bool __ret = true;
    00537       if (_M_names[1])
    00538     // We must actually compare all the _M_names: can be all equal!
    00539     for (size_t __i = 0; __ret && __i < _S_categories_size - 1; ++__i)
    00540       __ret = std::strcmp(_M_names[__i], _M_names[__i + 1]) == 0;
    00541       return __ret;
    00542     }
    00543
    00544     void
    00545     _M_replace_categories(const _Impl*, category);
    00546
    00547     void
    00548     _M_replace_category(const _Impl*, const locale::id* const*);
    00549
    00550     void
    00551     _M_replace_facet(const _Impl*, const locale::id*);
    00552
    00553     void
    00554     _M_install_facet(const locale::id*, const facet*);
    00555
    00556     template<typename _Facet>
    00557       inline void
    00558       _M_init_facet(_Facet* __facet)
    00559       { _M_install_facet(&_Facet::id, __facet); }
    00560
    00561     void
    00562     _M_install_cache(const facet* __cache, size_t __index) throw()
    00563     {
    00564       __cache->_M_add_reference();
    00565       _M_caches[__index] = __cache;
    00566     }
    00567   };
    00568
    00569   template<typename _Facet>
    00570     locale::locale(const locale& __other, _Facet* __f)
    00571     {
    00572       _M_impl = new _Impl(*__other._M_impl, 1);
    00573
    00574       try
    00575     { _M_impl->_M_install_facet(&_Facet::id, __f); }
    00576       catch(...)
    00577     {
    00578       _M_impl->_M_remove_reference();
    00579       __throw_exception_again;
    00580     }
    00581       delete [] _M_impl->_M_names[0];
    00582       _M_impl->_M_names[0] = 0;   // Unnamed.
    00583     }
    00584 } // namespace std
    00585
    00586 #endif