Localization library

 

C++

Compiler support

Freestanding and hosted

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Standard library headers

Named requirements

Feature test macros (C++20)

Language support library

Concepts library (C++20)

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Diagnostics library

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Iterators library

Ranges library (C++20)

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Filesystem library (C++17)

Regular expressions library (C++11)

Concurrency support library (C++11)

Execution support library (C++26)

Technical specifications

Symbols index

External libraries

 

Localization library

Locales and facets
Locales
has_facet use_facet	locale
Facet category base classes
ctype_base codecvt_base messages_base	time_base money_base
ctype facets
ctype ctype<char> ctype_byname	codecvt codecvt_byname
numeric facets
num_get num_put	numpunct numpunct_byname
collate facets
collate	collate_byname
time facets
time_get time_put	time_get_byname time_put_byname
monetary facets
money_get money_put	moneypunct moneypunct_byname
messages facets
messages	messages_byname

Character classification and conversion
Character classification
isspace isblank (C++11) iscntrl	isupper islower isalpha	ispunct isdigit isxdigit	isalnum isprint isgraph

Character conversions

toupper

tolower

String and stream conversions

wstring_convert (C++11/17/26*)

wbuffer_convert (C++11/17/26*)

Text encoding identifications

text_encoding (C++26)

Unicode conversion facets

codecvt_utf8 (C++11/17/26*)

codecvt_utf16 (C++11/17/26*)

codecvt_utf8_utf16 (C++11/17/26*)

codecvt_mode (C++11/17/26*)

C library locales
LC_ALLLC_COLLATELC_CTYPELC_MONETARYLC_NUMERICLC_TIME	setlocale localeconv lconv

 

The locale facility includes internationalization support for character classification and string collation, numeric, monetary, and date/time formatting and parsing, and message retrieval. Locale settings control the behavior of stream I/O, regular expression library, and other components of the C++ standard library.

Locales and facets

Defined in header <locale>
Locales
locale	set of polymorphic facets that encapsulate cultural differences (class)
use_facet	obtains a facet from a locale (function template)
has_facet	checks if a locale implements a specific facet (function template)
Facet category base classes
ctype_base	defines character classification categories (class)
codecvt_base	defines character conversion errors (class)
messages_base	defines messages catalog type (class)
time_base	defines date format constants (class)
money_base	defines monetary formatting patterns (class)
ctype facets
ctype	defines character classification tables (class template)
ctype_byname	represents the system-supplied std::ctype for the named locale (class template)
ctype<char>	specialization of std::ctype for type char (class template specialization)
codecvt	converts between character encodings, including UTF-8, UTF-16, UTF-32 (class template)
codecvt_byname	represents the system-supplied std::codecvt for the named locale (class template)
numeric facets
num_get	parses numeric values from an input character sequence (class template)
num_put	formats numeric values for output as character sequence (class template)
numpunct	defines numeric punctuation rules (class template)
numpunct_byname	represents the system-supplied std::numpunct for the named locale (class template)
collate facets
collate	defines lexicographical comparison and hashing of strings (class template)
collate_byname	represents the system-supplied std::collate for the named locale (class template)
time facets
time_get	parses time/date values from an input character sequence into std::tm (class template)
time_get_byname	represents the system-supplied std::time_get for the named locale (class template)
time_put	formats contents of std::tm for output as character sequence (class template)
time_put_byname	represents the system-supplied std::time_put for the named locale (class template)
monetary facets
money_get	parses and constructs a monetary value from an input character sequence (class template)
money_put	formats a monetary value for output as a character sequence (class template)
moneypunct	defines monetary formatting parameters used by std::money_get and std::money_put (class template)
moneypunct_byname	represents the system-supplied std::moneypunct for the named locale (class template)
messages facets
messages	implements retrieval of strings from message catalogs (class template)
messages_byname	represents the system-supplied std::messages for the named locale (class template)

Character classification and conversion

Defined in header <locale>
Character classification
isspace(std::locale)	checks if a character is classified as whitespace by a locale (function template)
isblank(std::locale) (C++11)	checks if a character is classified as a blank character by a locale (function template)
iscntrl(std::locale)	checks if a character is classified as a control character by a locale (function template)
isupper(std::locale)	checks if a character is classified as uppercase by a locale (function template)
islower(std::locale)	checks if a character is classified as lowercase by a locale (function template)
isalpha(std::locale)	checks if a character is classified as alphabetic by a locale (function template)
isdigit(std::locale)	checks if a character is classified as a digit by a locale (function template)
ispunct(std::locale)	checks if a character is classified as punctuation by a locale (function template)
isxdigit(std::locale)	checks if a character is classified as a hexadecimal digit by a locale (function template)
isalnum(std::locale)	checks if a character is classified as alphanumeric by a locale (function template)
isprint(std::locale)	checks if a character is classified as printable by a locale (function template)
isgraph(std::locale)	checks if a character is classified as graphical by a locale (function template)
Character conversions
toupper(std::locale)	converts a character to uppercase using the ctype facet of a locale (function template)
tolower(std::locale)	converts a character to lowercase using the ctype facet of a locale (function template)
String and stream conversions
wstring_convert (C++11)(deprecated in C++17)(removed in C++26)	performs conversions between a wide string and a byte string (class template)
wbuffer_convert (C++11)(deprecated in C++17)(removed in C++26)	performs conversion between a byte stream buffer and a wide stream buffer (class template)

Locale-independent unicode conversion facets Defined in header <codecvt> codecvt_utf8 (C++11)(deprecated in C++17)(removed in C++26) converts between UTF-8 and UCS-2/UCS-4 (class template) codecvt_utf16 (C++11)(deprecated in C++17)(removed in C++26) converts between UTF-16 and UCS-2/UCS-4 (class template) codecvt_utf8_utf16 (C++11)(deprecated in C++17)(removed in C++26) converts between UTF-8 and UTF-16 (class template) codecvt_mode (C++11)(deprecated in C++17)(removed in C++26) tags to alter behavior of the standard codecvt facets (enum)

(until C++26)

C library locales

Defined in header <clocale>
setlocale	gets and sets the current C locale (function)
LC_ALLLC_COLLATELC_CTYPELC_MONETARYLC_NUMERICLC_TIME	locale categories for std::setlocale (macro constant)
localeconv	queries numeric and monetary formatting details of the current locale (function)
lconv	formatting details, returned by std::localeconv (class)

Text encoding identifications Defined in header <text_encoding> text_encoding (C++26) describes an interface for accessing the IANA Character Sets registry (class)

(since C++26)

See also

C documentation for Localization support