LC_ALL, LC_COLLATE, LC_CTYPE, LC_MONETARY, LC_NUMERIC, LC_TIME

 

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Localizations 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_byname ctype<char>	codecvt codecvt_byname
numeric facets
num_get num_put	numpunct numpunct_byname
collate facets
collate	collate_byname
time facets
time_get time_get_byname	time_put 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	isdigit ispunct isxdigit isalnum isprint isgraph
Conversions
toupper tolower	wstring_convert (C++11/17*) wbuffer_convert (C++11/17*)
Code conversion facets
codecvt_utf8 (C++11/17*) codecvt_utf16 (C++11/17*)	codecvt_utf8_utf16 (C++11/17*) codecvt_mode (C++11/17*)
C locale
LC_ALLLC_COLLATELC_CTYPELC_MONETARYLC_NUMERICLC_TIME	setlocale localeconv lconv

 

Defined in header <clocale>
#define LC_ALL      /* implementation defined */
#define LC_COLLATE  /* implementation defined */
#define LC_CTYPE    /* implementation defined */
#define LC_MONETARY /* implementation defined */
#define LC_NUMERIC  /* implementation defined */
#define LC_TIME     /* implementation defined */

Each of the above macro constants expand to integer constant expressions with distinct values that are suitable for use as the first argument of std::setlocale.

Constant	Explanation
LC_ALL	selects the entire C locale
LC_COLLATE	selects the collation category of the C locale
LC_CTYPE	selects the character classification category of the C locale
LC_MONETARY	selects the monetary formatting category of the C locale
LC_NUMERIC	selects the numeric formatting category of the C locale
LC_TIME	selects the time formatting category of the C locale

Additional macro constants, with names that begin with LC_ followed by at least one uppercase letter, may be defined in <clocale>. For example, the POSIX specification requires LC_MESSAGES (which controls std::perror and std::strerror), ISO/IEC 30112:2014 (2014 draft) additionally defines LC_IDENTIFICATION, LC_XLITERATE, LC_NAME, LC_ADDRESS, LC_TELEPHONE, LC_PAPER, LC_MEASUREMENT, and LC_KEYBOARD, which are supported by the GNU C library (except for LC_XLITERATE).

Example

Run this code

#include <cstdio>
#include <clocale>
#include <ctime>
#include <cwchar>
 
int main()
{
    // the C locale will be the UTF-8 enabled English:
    std::setlocale(LC_ALL, "en_US.UTF-8");
 
    // decimal dot will be German:
    std::setlocale(LC_NUMERIC, "de_DE.UTF-8");
 
    // date/time formatting will be Japanese:
    std::setlocale(LC_TIME, "ja_JP.UTF-8");
 
    wchar_t str[100];
    std::time_t t = std::time(nullptr);
    std::wcsftime(str, 100, L"%A %c", std::localtime(&t));
    std::wprintf(L"Number: %.2f\nDate: %Ls\n", 3.14, str);
}

Output:

Number: 3,14
Date: 日曜日 2022年11月06日 17時55分10秒

See also

setlocale	gets and sets the current C locale (function)
locale	set of polymorphic facets that encapsulate cultural differences (class)