# std::locale Class Reference

List of all members.

## Detailed Description

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.

Definition at line 66 of file locale_classes.h.

## Public Types

- typedef int category

## Public Member Functions

- template<typename _Facet> locale combine (const locale &__other) const
- template<typename _Facet> locale (const locale &__other, _Facet *__f)
- locale (const locale &__base, const locale &__add, category __cat)
- locale (const locale &__base, const char *__s, category __cat)
- locale (const char *__s)
- locale (const locale &__other) throw ()
- locale () throw ()
- string name () const
- bool operator!= (const locale &__other) const throw ()
- template<typename _Char, typename _Traits, typename _Alloc> bool operator() (const basic_string< _Char, _Traits, _Alloc > &__s1, const basic_string< _Char, _Traits, _Alloc > &__s2) const
- const locale & operator= (const locale &__other) throw ()
- bool operator== (const locale &__other) const throw ()
- ~locale () throw ()

## Static Public Member Functions

- static const locale & classic ()
- static locale global (const locale &)

## Static Public Attributes

- static const category all
- static const category collate
- static const category ctype
- static const category messages
- static const category monetary
- static const category none
- static const category numeric
- static const category time

## Friends

- struct __use_cache
- class _Impl
- class facet
- template<typename _Facet> bool has_facet (const locale &) throw ()
- template<typename _Facet> const _Facet & use_facet (const locale &)

## Classes

- class _Impl
- class facet
    Localization functionality base class. More...
- class id
    Facet ID class. More...

## Member Typedef Documentation

typedef int std::locale::category

Definition of locale::category.

Definition at line 71 of file locale_classes.h.

## Constructor & Destructor Documentation

std::locale::locale | ( |  | ) | throw ()

Default constructor.

Constructs a copy of the global locale. If no locale has been explicitly set, this is the "C" locale.

std::locale::locale | ( | const locale & | __other | ) | throw ()

Copy constructor.

Constructs a copy of other.

Parameters:

  | other | The locale to copy.

std::locale::locale | ( | const char * | __s | ) | `[explicit]`

Named locale constructor.

Constructs a copy of the named C library locale.

Parameters:

  | s | Name of the locale to construct.

Exceptions:

  | std::runtime_error | if s is null or an undefined locale.

std::locale::locale | ( | const locale & | __base,
|  | const char * | __s,
|  | category | __cat |
| ) |  |  |

Construct locale with facets from another locale.

Constructs a copy of the locale base. The facets specified by cat are replaced with those from the locale named by s. If base is named, this locale instance will also be named.

Parameters:

  | base | The locale to copy.
  | s | Name of the locale to use facets from.
  | cat | Set of categories defining the facets to use from s.

Exceptions:

  | std::runtime_error | if s is null or an undefined locale.

std::locale::locale | ( | const locale & | __base,
|  | const locale & | __add,
|  | category | __cat |
| ) |  |  |

Construct locale with facets from another locale.

Constructs a copy of the locale base. The facets specified by cat are replaced with those from the locale add. If base and add are named, this locale instance will also be named.

Parameters:

  | base | The locale to copy.
  | add | The locale to use facets from.
  | cat | Set of categories defining the facets to use from add.

template<typename _Facet>

std::locale::locale | ( | const locale & | __other,
|  | _Facet * | __f |
| ) |  |  |

Construct locale with another facet.

Constructs a copy of the locale other. The facet is added to , replacing an existing facet of type Facet if there is one. If is null, this locale is a copy of other.

Parameters:

  | other | The locale to copy.
  | f | The facet to add in.

Definition at line 565 of file locale_classes.h.

References _Impl, and _M_impl.

std::locale::~locale | ( |  | ) | throw ()

Locale destructor.

## Member Function Documentation

static const locale& std::locale::classic | ( |  | ) | `[static]`

Return reference to the "C" locale.

template<typename _Facet>

locale std::locale::combine | ( | const locale & | __other | ) | const

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 other into the new locale.

Parameters:

  | Facet | The facet type to copy from other
  | other | The locale to copy from.

Returns:
  Newly constructed locale.

Exceptions:

  | std::runtime_error | if other has no facet of type Facet.

Definition at line 50 of file locale_facets.tcc.

References std::locale::_Impl::_M_remove_reference(), and std::locale::_Impl::_M_replace_facet().

static locale std::locale::global | ( | const locale & |  | ) | `[static]`

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()).

Parameters:

  | locale | The new locale to make global.

Returns:
  Copy of the old global locale.

string std::locale::name | ( |  | ) | const

Return locale name.

Returns:
  Locale name or "*" if unnamed.

bool std::locale::operator!= | ( | const locale & | __other | ) | const throw ()`[inline]`

Locale inequality.

Parameters:

  | other | The locale to compare against.

Returns:
  ! (*this == other)

Definition at line 240 of file locale_classes.h.

References std::tr1::operator==().

template<typename _CharT, typename _Traits, typename _Alloc>

bool std::locale::operator() | ( | const basic_string< _Char, _Traits, _Alloc > & | __s1,
|  | const basic_string< _Char, _Traits, _Alloc > & | __s2 |
| ) |  |  | const

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:

      std::sort(v.begin(), v.end(), loc);

Parameters:

  | s1 | First string to compare.
  | s2 | Second string to compare.

Returns:
  True if collate<Char> facet compares s1 < s2, else false.

Definition at line 67 of file locale_facets.tcc.

References std::basic_string< _CharT, _Traits, _Alloc >::data(), and std::basic_string< _CharT, _Traits, _Alloc >::length().

const locale& std::locale::operator= | ( | const locale & | __other | ) | throw ()

Assignment operator.

Set this locale to be a copy of other.

Parameters:

  | other | The locale to copy.

Returns:
  A reference to this locale.

bool std::locale::operator== | ( | const locale & | __other | ) | const throw ()

Locale equality.

Parameters:

  | other | The locale to compare against.

Returns:
  True if other and this refer to the same locale instance, are copies, or have the same name. False otherwise.

## Friends And Related Function Documentation

template<typename _Facet>

bool has_facet | ( | const locale & | __loc | ) | throw ()`[friend]`

Test for the presence of a facet.

has_facet tests the locale argument for the presence of the facet type provided as the template parameter. Facets derived from the facet parameter will also return true.

Parameters:

  | Facet | The facet type to test the presence of.
  | locale | The locale to test.

Returns:
  true if locale contains a facet of type Facet, else false.

Definition at line 89 of file locale_facets.tcc.

template<typename _Facet>

const _Facet& use_facet | ( | const locale & | __loc | ) | `[friend]`

Return a facet.

use_facet looks for and returns a reference to a facet of type Facet where Facet is the template parameter. If has_facet(locale) is true, there is a suitable facet to return. It throws std::bad_cast if the locale doesn't contain a facet of type Facet.

Parameters:

  | Facet | The facet type to access.
  | locale | The locale to use.

Returns:
  Reference to facet of type Facet.

Exceptions:

  | std::bad_cast | if locale doesn't contain a facet of type Facet.

Definition at line 111 of file locale_facets.tcc.

## Member Data Documentation

const category std::locale::none`[static]`

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.

Definition at line 104 of file locale_classes.h.

The documentation for this class was generated from the following files:

- locale_classes.h
- locale_facets.tcc