std::locale(3cxx)

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version 14-20240412 · 21 versions
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✨ std::locale(3cxx) ✨

🌸 NAME 🌸

std::locale — container class for localization functionality. 💖

🦋 SYNOPSIS 🦋

#include <locale>

🎀 Classes

  • class facet — Localization functionality base class.
  • class id — Facet ID class.

🎀 Public Types

  • typedef int category — Definition of locale::category.

🎀 Public Member Functions

  • locale () throw () — Default constructor.
  • locale (const char *__s) — Named locale constructor.
  • locale (const locale &__base, const char *__s, category __cat) — Construct locale with facets from another locale.
  • locale (const locale &__base, const locale &__add, category __cat) — Construct locale with facets from another locale.
  • locale (const locale &__base, const std::string &__s, category __cat) — Construct locale with facets from another locale.
  • locale (const locale &__other) throw () — Copy constructor.
  • template<typename _Facet > locale (const locale &__other, _Facet *__f) — Construct locale with another facet.
  • locale (const std::string &__s) — Named locale constructor.
  • ~locale () throw () — Locale destructor.
  • template<typename _Facet > locale combine (const locale &__other) const — Construct locale with another facet.
  • string name () const — Return locale name.
  • template<typename _Char , typename _Traits , typename _Alloc > bool operator() (const basic_string< _Char, _Traits, _Alloc > &__s1, const basic_string< _Char, _Traits, _Alloc > &__s2) const — Compare two strings according to collate.
  • template<typename _CharT , typename _Traits , typename _Alloc > bool operator() (const basic_string< _CharT, _Traits, _Alloc > &__s1, const basic_string< _CharT, _Traits, _Alloc > &__s2) const — another operator() overload listed in the synopsis.
  • const locale & operator= (const locale &__other) throw () — Assignment operator.
  • bool operator== (const locale &__other) const throw () — Locale equality.

🎀 Static Public Member Functions

  • static const locale & classic () — Return reference to the C locale.
  • static locale global (const locale &__loc) — Set global locale.

🎀 Static Public Attributes

  • static const category none — Category values.
  • static const category ctype — Category values.
  • static const category numeric — Category values.
  • static const category collate — Category values.
  • static const category time — Category values.
  • static const category monetary — Category values.
  • static const category messages — Category values.
  • static const category all — Category values.

🎀 Friends

  • template<typename _Facet > const _Facet * __try_use_facet (const locale &) noexcept
  • template<typename _Cache > struct __use_cache
  • class _Impl
  • class facet
  • template<typename _Facet > bool has_facet (const locale &) throw () — Test for the presence of a facet.
  • template<typename _Facet > const _Facet & use_facet (const locale &) — Return a facet.

💜 DETAILED DESCRIPTION 💜

Okay so bestie, here’s the whole vibe: std::locale is first a class wrapper for C library locales. It’s 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. 💸⏰🔢

Important: Constructing C++ locales does not change the C library locale. periodt.

This library supports efficient construction and copying of locales through a reference counting implementation of the locale class. ✨

🎀 MEMBER TYPEDEF DOCUMENTATION 🎀

typedef int std::locale::category

Definition of locale::category.

🌸 CONSTRUCTOR & DESTRUCTOR DOCUMENTATION 🌸

std::locale::locale ()

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

Referenced by combine().

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

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 std::string & __s) [inline], [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 an undefined locale.

std::locale::locale (const locale & __base, const std::string & __s, category __cat) [inline]

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 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 __f is added to __other, replacing an existing facet of type Facet if there is one. If __f is null, this locale is a copy of __other.

Parameters

  • __other — The locale to copy.
  • __f — The facet to add in.

std::locale::~locale ()

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.

Template Parameters

  • _Facet — The facet type to copy from other

Parameters

  • __other — The locale to copy from.

Returns

  • Newly constructed locale.

Exceptions

  • std::runtime_error if __other has no facet of type _Facet.

References locale().

static locale std::locale::global (const locale & __loc) [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

  • __loc — 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.

template<typename _Char , 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.

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

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

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.

References operator==().

Referenced by operator==().

template<typename _Facet > bool has_facet (const locale &) [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.

Template Parameters

  • _Facet — The facet type to test the presence of.

Parameters

  • __loc — The locale to test.

Returns

  • true if __loc contains a facet of type _Facet, else false.

template<typename _Facet > const _Facet & use_facet (const locale &) [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.

Template Parameters

  • _Facet — The facet type to access.

Parameters

  • __loc — The locale to use.

Returns

  • Reference to facet of type Facet.

Exceptions

  • std::bad_cast if __loc doesn’t contain a facet of type _Facet.

💾 Member Data Documentation

Okay bestie, this is the part where all the categories live — every single one of them is a const category static member, so let's go through them one by one, no skipping, no cap 💅

Here's the whole spiel once so you have it in your head, because it applies to every one of these bad boys: the standard category values are none, ctype, numeric, collate, time, monetary, and messages. They form a bitmask that supports union and intersection, and the category all is the union of these values. 🫶

⚠️ NB: Order must match _S_facet_categories definition in locale.cc — yes, that's literally a requirement, do not reorder these, iykyk 💀

💖 const category std::locale::all [static]

Category values, babes. The standard category values are none, ctype, numeric, collate, time, monetary, and messages — that's the whole squad. They form a bitmask that supports union and intersection, and all is literally the union of these values, so it's giving "everyone's invited to the party" ✨

⚠️ NB: Order must match _S_facet_categories definition in locale.cc

🎀 const category std::locale::collate [static]

Category values, bestie. The standard category values are none, ctype, numeric, collate, time, monetary, and messages. They form a bitmask that supports union and intersection, and the category all is the union of these values. This one's the collate era 🦋

⚠️ NB: Order must match _S_facet_categories definition in locale.cc

🌸 const category std::locale::ctype [static]

Category values, fr fr. The standard category values are none, ctype, numeric, collate, time, monetary, and messages. They form a bitmask that supports union and intersection, and all is the union of these values — she's the character-classification main character here 👑

⚠️ NB: Order must match _S_facet_categories definition in locale.cc

🦋 const category std::locale::messages [static]

Category values, okay so. The standard category values are none, ctype, numeric, collate, time, monetary, and messages. They form a bitmask that supports union and intersection, and the category all is the union of these values. Message catalog vibes only 📬

⚠️ NB: Order must match _S_facet_categories definition in locale.cc

🍓 const category std::locale::monetary [static]

Category values, ngl. The standard category values are none, ctype, numeric, collate, time, monetary, and messages. They form a bitmask that supports union and intersection, and all is the union of these values. Money moves 💸

⚠️ NB: Order must match _S_facet_categories definition in locale.cc

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

Category values, lowkey the starting point. The standard category values are none, ctype, numeric, collate, time, monetary, and messages. They form a bitmask that supports union and intersection, and the category all is the union of these values. She's the empty set of the group chat 🙈

⚠️ NB: Order must match _S_facet_categories definition in locale.cc

🔥 const category std::locale::numeric [static]

Category values, periodt. The standard category values are none, ctype, numeric, collate, time, monetary, and messages. They form a bitmask that supports union and intersection, and all is the union of these values — numbers, formatted and iconic 🔢

⚠️ NB: Order must match _S_facet_categories definition in locale.cc

⭐ const category std::locale::time [static]

Category values, bestie, last but never least. The standard category values are none, ctype, numeric, collate, time, monetary, and messages. They form a bitmask that supports union and intersection, and the category all is the union of these values. Clock app energy ⏰

⚠️ NB: Order must match _S_facet_categories definition in locale.cc

👑 Author

Generated automatically by Doxygen for libstdc++ from the source code. Not me writing a love letter by hand, it's the robots doing it 🤖💜

And that's a wrap on std::locale(3cxx), bestie! 🌈 This lil masterpiece came straight out of the libstdc++ source, and it's dated the same day the doc fairies ran Doxygen on it. Go forth and localize, and remember: respect the category order, or it's giving undefined chaos 💀✨

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