locale_classes.h
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// Locale support -*- C++ -*-
// Copyright (C) 1997-2013 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.
// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
// <http://www.gnu.org/licenses/>.
/** @file bits/locale_classes.h
* This is an internal header file, included by other library headers.
* Do not attempt to use it directly. @headername{locale}
*/
//
// ISO C++ 14882: 22.1 Locales
//
#ifndef _LOCALE_CLASSES_H
#define _LOCALE_CLASSES_H 1
#pragma GCC system_header
#include <bits/localefwd.h>
#include <string>
#include <ext/atomicity.h>
namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
// 22.1.1 Class locale
/**
* @brief Container class for localization functionality.
* @ingroup locales
*
* The locale class is first a class wrapper for C library locales. It is
* also an extensible container for user-defined localization. A locale is
* a collection of facets that implement various localization features such
* as money, time, and number printing.
*
* Constructing C++ locales does not change the C library locale.
*
* This library supports efficient construction and copying of locales
* through a reference counting implementation of the locale class.
*/
class locale
{
public:
// Types:
/// Definition of locale::category.
typedef int category;
// Forward decls and friends:
class facet;
class id;
class _Impl;
friend class facet;
friend class _Impl;
template<typename _Facet>
friend bool
has_facet(const locale&) throw();
template<typename _Facet>
friend const _Facet&
use_facet(const locale&);
template<typename _Cache>
friend struct __use_cache;
//@{
/**
* @brief Category values.
*
* The standard category values are none, ctype, numeric, collate, time,
* monetary, and messages. They form a bitmask that supports union and
* intersection. The category all is the union of these values.
*
* NB: Order must match _S_facet_categories definition in locale.cc
*/
static const category none = 0;
static const category ctype = 1L << 0;
static const category numeric = 1L << 1;
static const category collate = 1L << 2;
static const category time = 1L << 3;
static const category monetary = 1L << 4;
static const category messages = 1L << 5;
static const category all = (ctype | numeric | collate |
time | monetary | messages);
//@}
// Construct/copy/destroy:
/**
* @brief Default constructor.
*
* Constructs a copy of the global locale. If no locale has been
* explicitly set, this is the C locale.
*/
locale() throw();
/**
* @brief Copy constructor.
*
* Constructs a copy of @a other.
*
* @param __other The locale to copy.
*/
locale(const locale& __other) throw();
/**
* @brief Named locale constructor.
*
* Constructs a copy of the named C library locale.
*
* @param __s Name of the locale to construct.
* @throw std::runtime_error if __s is null or an undefined locale.
*/
explicit
locale(const char* __s);
/**
* @brief Construct locale with facets from another locale.
*
* Constructs a copy of the locale @a base. The facets specified by @a
* cat are replaced with those from the locale named by @a s. If base is
* named, this locale instance will also be named.
*
* @param __base The locale to copy.
* @param __s Name of the locale to use facets from.
* @param __cat Set of categories defining the facets to use from __s.
* @throw std::runtime_error if __s is null or an undefined locale.
*/
locale(const locale& __base, const char* __s, category __cat);
/**
* @brief Construct locale with facets from another locale.
*
* Constructs a copy of the locale @a base. The facets specified by @a
* cat are replaced with those from the locale @a add. If @a base and @a
* add are named, this locale instance will also be named.
*
* @param __base The locale to copy.
* @param __add The locale to use facets from.
* @param __cat Set of categories defining the facets to use from add.
*/
locale(const locale& __base, const locale& __add, category __cat);
/**
* @brief Construct locale with another facet.
*
* Constructs a copy of the locale @a __other. The facet @a __f
* is added to @a __other, replacing an existing facet of type
* Facet if there is one. If @a __f is null, this locale is a
* copy of @a __other.
*
* @param __other The locale to copy.
* @param __f The facet to add in.
*/
template<typename _Facet>
locale(const locale& __other, _Facet* __f);
/// Locale destructor.
~locale() throw();
/**
* @brief Assignment operator.
*
* Set this locale to be a copy of @a other.
*
* @param __other The locale to copy.
* @return A reference to this locale.
*/
const locale&
operator=(const locale& __other) throw();
/**
* @brief Construct locale with another facet.
*
* Constructs and returns a new copy of this locale. Adds or replaces an
* existing facet of type Facet from the locale @a other into the new
* locale.
*
* @tparam _Facet The facet type to copy from other
* @param __other The locale to copy from.
* @return Newly constructed locale.
* @throw std::runtime_error if __other has no facet of type _Facet.
*/
template<typename _Facet>
locale
combine(const locale& __other) const;
// Locale operations:
/**
* @brief Return locale name.
* @return Locale name or "*" if unnamed.
*/
string
name() const;
/**
* @brief Locale equality.
*
* @param __other The locale to compare against.
* @return True if other and this refer to the same locale instance, are
* copies, or have the same name. False otherwise.
*/
bool
operator==(const locale& __other) const throw();
/**
* @brief Locale inequality.
*
* @param __other The locale to compare against.
* @return ! (*this == __other)
*/
bool
operator!=(const locale& __other) const throw()
{ return !(this->operator==(__other)); }
/**
* @brief Compare two strings according to collate.
*
* Template operator to compare two strings using the compare function of
* the collate facet in this locale. One use is to provide the locale to
* the sort function. For example, a vector v of strings could be sorted
* according to locale loc by doing:
* @code
* std::sort(v.begin(), v.end(), loc);
* @endcode
*
* @param __s1 First string to compare.
* @param __s2 Second string to compare.
* @return True if collate<_Char> facet compares __s1 < __s2, else false.
*/
template<typename _Char, typename _Traits, typename _Alloc>
bool
operator()(const basic_string<_Char, _Traits, _Alloc>& __s1,
const basic_string<_Char, _Traits, _Alloc>& __s2) const;
// Global locale objects:
/**
* @brief Set global locale
*
* This function sets the global locale to the argument and returns a
* copy of the previous global locale. If the argument has a name, it
* will also call std::setlocale(LC_ALL, loc.name()).
*
* @param __loc The new locale to make global.
* @return Copy of the old global locale.
*/
static locale
global(const locale& __loc);
/**
* @brief Return reference to the C locale.
*/
static const locale&
classic();
private:
// The (shared) implementation
_Impl* _M_impl;
// The "C" reference locale
static _Impl* _S_classic;
// Current global locale
static _Impl* _S_global;
// Names of underlying locale categories.
// NB: locale::global() has to know how to modify all the
// underlying categories, not just the ones required by the C++
// standard.
static const char* const* const _S_categories;
// Number of standard categories. For C++, these categories are
// collate, ctype, monetary, numeric, time, and messages. These
// directly correspond to ISO C99 macros LC_COLLATE, LC_CTYPE,
// LC_MONETARY, LC_NUMERIC, and LC_TIME. In addition, POSIX (IEEE
// 1003.1-2001) specifies LC_MESSAGES.
// In addition to the standard categories, the underlying
// operating system is allowed to define extra LC_*
// macros. For GNU systems, the following are also valid:
// LC_PAPER, LC_NAME, LC_ADDRESS, LC_TELEPHONE, LC_MEASUREMENT,
// and LC_IDENTIFICATION.
enum { _S_categories_size = 6 + _GLIBCXX_NUM_CATEGORIES };
#ifdef __GTHREADS
static __gthread_once_t _S_once;
#endif
explicit
locale(_Impl*) throw();
static void
_S_initialize();
static void
_S_initialize_once() throw();
static category
_S_normalize_category(category);
void
_M_coalesce(const locale& __base, const locale& __add, category __cat);
};
// 22.1.1.1.2 Class locale::facet
/**
* @brief Localization functionality base class.
* @ingroup locales
*
* The facet class is the base class for a localization feature, such as
* money, time, and number printing. It provides common support for facets
* and reference management.
*
* Facets may not be copied or assigned.
*/
class locale::facet
{
private:
friend class locale;
friend class locale::_Impl;
mutable _Atomic_word _M_refcount;
// Contains data from the underlying "C" library for the classic locale.
static __c_locale _S_c_locale;
// String literal for the name of the classic locale.
static const char _S_c_name[2];
#ifdef __GTHREADS
static __gthread_once_t _S_once;
#endif
static void
_S_initialize_once();
protected:
/**
* @brief Facet constructor.
*
* This is the constructor provided by the standard. If refs is 0, the
* facet is destroyed when the last referencing locale is destroyed.
* Otherwise the facet will never be destroyed.
*
* @param __refs The initial value for reference count.
*/
explicit
facet(size_t __refs = 0) throw() : _M_refcount(__refs ? 1 : 0)
{ }
/// Facet destructor.
virtual
~facet();
static void
_S_create_c_locale(__c_locale& __cloc, const char* __s,
__c_locale __old = 0);
static __c_locale
_S_clone_c_locale(__c_locale& __cloc) throw();
static void
_S_destroy_c_locale(__c_locale& __cloc);
static __c_locale
_S_lc_ctype_c_locale(__c_locale __cloc, const char* __s);
// Returns data from the underlying "C" library data for the
// classic locale.
static __c_locale
_S_get_c_locale();
_GLIBCXX_CONST static const char*
_S_get_c_name() throw();
private:
void
_M_add_reference() const throw()
{ __gnu_cxx::__atomic_add_dispatch(&_M_refcount, 1); }
void
_M_remove_reference() const throw()
{
// Be race-detector-friendly. For more info see bits/c++config.
_GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_M_refcount);
if (__gnu_cxx::__exchange_and_add_dispatch(&_M_refcount, -1) == 1)
{
_GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_M_refcount);
__try
{ delete this; }
__catch(...)
{ }
}
}
facet(const facet&); // Not defined.
facet&
operator=(const facet&); // Not defined.
};
// 22.1.1.1.3 Class locale::id
/**
* @brief Facet ID class.
* @ingroup locales
*
* The ID class provides facets with an index used to identify them.
* Every facet class must define a public static member locale::id, or be
* derived from a facet that provides this member, otherwise the facet
* cannot be used in a locale. The locale::id ensures that each class
* type gets a unique identifier.
*/
class locale::id
{
private:
friend class locale;
friend class locale::_Impl;
template<typename _Facet>
friend const _Facet&
use_facet(const locale&);
template<typename _Facet>
friend bool
has_facet(const locale&) throw();
// NB: There is no accessor for _M_index because it may be used
// before the constructor is run; the effect of calling a member
// function (even an inline) would be undefined.
mutable size_t _M_index;
// Last id number assigned.
static _Atomic_word _S_refcount;
void
operator=(const id&); // Not defined.
id(const id&); // Not defined.
public:
// NB: This class is always a static data member, and thus can be
// counted on to be zero-initialized.
/// Constructor.
id() { }
size_t
_M_id() const throw();
};
// Implementation object for locale.
class locale::_Impl
{
public:
// Friends.
friend class locale;
friend class locale::facet;
template<typename _Facet>
friend bool
has_facet(const locale&) throw();
template<typename _Facet>
friend const _Facet&
use_facet(const locale&);
template<typename _Cache>
friend struct __use_cache;
private:
// Data Members.
_Atomic_word _M_refcount;
const facet** _M_facets;
size_t _M_facets_size;
const facet** _M_caches;
char** _M_names;
static const locale::id* const _S_id_ctype[];
static const locale::id* const _S_id_numeric[];
static const locale::id* const _S_id_collate[];
static const locale::id* const _S_id_time[];
static const locale::id* const _S_id_monetary[];
static const locale::id* const _S_id_messages[];
static const locale::id* const* const _S_facet_categories[];
void
_M_add_reference() throw()
{ __gnu_cxx::__atomic_add_dispatch(&_M_refcount, 1); }
void
_M_remove_reference() throw()
{
// Be race-detector-friendly. For more info see bits/c++config.
_GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_M_refcount);
if (__gnu_cxx::__exchange_and_add_dispatch(&_M_refcount, -1) == 1)
{
_GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_M_refcount);
__try
{ delete this; }
__catch(...)
{ }
}
}
_Impl(const _Impl&, size_t);
_Impl(const char*, size_t);
_Impl(size_t) throw();
~_Impl() throw();
_Impl(const _Impl&); // Not defined.
void
operator=(const _Impl&); // Not defined.
bool
_M_check_same_name()
{
bool __ret = true;
if (_M_names[1])
// We must actually compare all the _M_names: can be all equal!
for (size_t __i = 0; __ret && __i < _S_categories_size - 1; ++__i)
__ret = __builtin_strcmp(_M_names[__i], _M_names[__i + 1]) == 0;
return __ret;
}
void
_M_replace_categories(const _Impl*, category);
void
_M_replace_category(const _Impl*, const locale::id* const*);
void
_M_replace_facet(const _Impl*, const locale::id*);
void
_M_install_facet(const locale::id*, const facet*);
template<typename _Facet>
void
_M_init_facet(_Facet* __facet)
{ _M_install_facet(&_Facet::id, __facet); }
void
_M_install_cache(const facet*, size_t);
};
/**
* @brief Facet for localized string comparison.
*
* This facet encapsulates the code to compare strings in a localized
* manner.
*
* The collate template uses protected virtual functions to provide
* the actual results. The public accessors forward the call to
* the virtual functions. These virtual functions are hooks for
* developers to implement the behavior they require from the
* collate facet.
*/
template<typename _CharT>
class collate : public locale::facet
{
public:
// Types:
//@{
/// Public typedefs
typedef _CharT char_type;
typedef basic_string<_CharT> string_type;
//@}
protected:
// Underlying "C" library locale information saved from
// initialization, needed by collate_byname as well.
__c_locale _M_c_locale_collate;
public:
/// Numpunct facet id.
static locale::id id;
/**
* @brief Constructor performs initialization.
*
* This is the constructor provided by the standard.
*
* @param __refs Passed to the base facet class.
*/
explicit
collate(size_t __refs = 0)
: facet(__refs), _M_c_locale_collate(_S_get_c_locale())
{ }
/**
* @brief Internal constructor. Not for general use.
*
* This is a constructor for use by the library itself to set up new
* locales.
*
* @param __cloc The C locale.
* @param __refs Passed to the base facet class.
*/
explicit
collate(__c_locale __cloc, size_t __refs = 0)
: facet(__refs), _M_c_locale_collate(_S_clone_c_locale(__cloc))
{ }
/**
* @brief Compare two strings.
*
* This function compares two strings and returns the result by calling
* collate::do_compare().
*
* @param __lo1 Start of string 1.
* @param __hi1 End of string 1.
* @param __lo2 Start of string 2.
* @param __hi2 End of string 2.
* @return 1 if string1 > string2, -1 if string1 < string2, else 0.
*/
int
compare(const _CharT* __lo1, const _CharT* __hi1,
const _CharT* __lo2, const _CharT* __hi2) const
{ return this->do_compare(__lo1, __hi1, __lo2, __hi2); }
/**
* @brief Transform string to comparable form.
*
* This function is a wrapper for strxfrm functionality. It takes the
* input string and returns a modified string that can be directly
* compared to other transformed strings. In the C locale, this
* function just returns a copy of the input string. In some other
* locales, it may replace two chars with one, change a char for
* another, etc. It does so by returning collate::do_transform().
*
* @param __lo Start of string.
* @param __hi End of string.
* @return Transformed string_type.
*/
string_type
transform(const _CharT* __lo, const _CharT* __hi) const
{ return this->do_transform(__lo, __hi); }
/**
* @brief Return hash of a string.
*
* This function computes and returns a hash on the input string. It
* does so by returning collate::do_hash().
*
* @param __lo Start of string.
* @param __hi End of string.
* @return Hash value.
*/
long
hash(const _CharT* __lo, const _CharT* __hi) const
{ return this->do_hash(__lo, __hi); }
// Used to abstract out _CharT bits in virtual member functions, below.
int
_M_compare(const _CharT*, const _CharT*) const throw();
size_t
_M_transform(_CharT*, const _CharT*, size_t) const throw();
protected:
/// Destructor.
virtual
~collate()
{ _S_destroy_c_locale(_M_c_locale_collate); }
/**
* @brief Compare two strings.
*
* This function is a hook for derived classes to change the value
* returned. @see compare().
*
* @param __lo1 Start of string 1.
* @param __hi1 End of string 1.
* @param __lo2 Start of string 2.
* @param __hi2 End of string 2.
* @return 1 if string1 > string2, -1 if string1 < string2, else 0.
*/
virtual int
do_compare(const _CharT* __lo1, const _CharT* __hi1,
const _CharT* __lo2, const _CharT* __hi2) const;
/**
* @brief Transform string to comparable form.
*
* This function is a hook for derived classes to change the value
* returned.
*
* @param __lo Start.
* @param __hi End.
* @return transformed string.
*/
virtual string_type
do_transform(const _CharT* __lo, const _CharT* __hi) const;
/**
* @brief Return hash of a string.
*
* This function computes and returns a hash on the input string. This
* function is a hook for derived classes to change the value returned.
*
* @param __lo Start of string.
* @param __hi End of string.
* @return Hash value.
*/
virtual long
do_hash(const _CharT* __lo, const _CharT* __hi) const;
};
template<typename _CharT>
locale::id collate<_CharT>::id;
// Specializations.
template<>
int
collate<char>::_M_compare(const char*, const char*) const throw();
template<>
size_t
collate<char>::_M_transform(char*, const char*, size_t) const throw();
#ifdef _GLIBCXX_USE_WCHAR_T
template<>
int
collate<wchar_t>::_M_compare(const wchar_t*, const wchar_t*) const throw();
template<>
size_t
collate<wchar_t>::_M_transform(wchar_t*, const wchar_t*, size_t) const throw();
#endif
/// class collate_byname [22.2.4.2].
template<typename _CharT>
class collate_byname : public collate<_CharT>
{
public:
//@{
/// Public typedefs
typedef _CharT char_type;
typedef basic_string<_CharT> string_type;
//@}
explicit
collate_byname(const char* __s, size_t __refs = 0)
: collate<_CharT>(__refs)
{
if (__builtin_strcmp(__s, "C") != 0
&& __builtin_strcmp(__s, "POSIX") != 0)
{
this->_S_destroy_c_locale(this->_M_c_locale_collate);
this->_S_create_c_locale(this->_M_c_locale_collate, __s);
}
}
protected:
virtual
~collate_byname() { }
};
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace
# include <bits/locale_classes.tcc>
#endif