std::numpunct_byname

 

C++

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Named requirements

Language support library

Concepts library (C++20)

Diagnostics library

Utilities library

Strings library

Containers library

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Ranges library (C++20)

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Technical Specifications

 

Localizations library

Locales and facets
locale
use_facet	has_facet
Character classification
isspace isblank (C++11) iscntrl isupper islower isalpha	isdigit ispunct isxdigit isalnum isprint isgraph
Conversions
toupper tolower	wstring_convert (C++11) wbuffer_convert (C++11)
Facet category base classes
ctype_base codecvt_base messages_base	time_base money_base
Facet categories
ctype ctype<char> codecvt collate messages time_get time_put	num_get num_put numpunct money_get money_put moneypunct
Locale-specific facets
ctype_byname codecvt_byname messages_byname collate_byname	time_get_byname time_put_byname numpunct_byname moneypunct_byname
Code conversion facets
codecvt_utf8 (C++11) codecvt_utf16 (C++11)	codecvt_utf8_utf16 (C++11) codecvt_mode (C++11)
C locale
setlocale localeconv lconv	LC_ALLLC_COLLATELC_CTYPELC_MONETARYLC_NUMERICLC_TIME

 

Defined in header <locale>
template< class CharT > class numpunct_byname : public std::numpunct<CharT>;

std::numpunct_byname is a std::numpunct facet which encapsulates numeric punctuation preferences of a locale specified at its construction.

Two specializations are provided by the standard library

Defined in header <locale>
std::numpunct_byname<char>	locale-specific std::numpunct facet for narrow character I/O
std::numpunct_byname<wchar_t>	locale-specific std::numpunct facet for wide characters I/O

Member types

Member type	Definition
char_type	CharT
string_type	std::basic_string<CharT>

Member functions

(constructor)	constructs a new numpunct_byname facet (public member function)
(destructor)	destroys a numpunct_byname facet (protected member function)

std::numpunct_byname::numpunct_byname

explicit numpunct_byname( const char* name, std::size_t refs = 0 );
explicit numpunct_byname( const std::string& name, std::size_t refs = 0 );		(since C++11)

Constructs a new std::numpunct_byname facet for a locale with name.

refs is used for resource management: if refs == 0, the implementation destroys the facet, when the last std::locale object holding it is destroyed. Otherwise, the object is not destroyed.

Parameters

name	-	the name of the locale
refs	-	the number of references that link to the facet

std::numpunct_byname::~numpunct_byname

protected: ~numpunct_byname();

Destroys the facet.

Inherited from std::numpunct

Member types

Member type	Definition
char_type	charT
string_type	std::basic_string<charT>

Member functions

decimal_point	invokes do_decimal_point (public member function of std::numpunct<CharT>)
thousands_sep	invokes do_thousands_sep (public member function of std::numpunct<CharT>)
grouping	invokes do_grouping (public member function of std::numpunct<CharT>)
truenamefalsename	invokes do_truename or do_falsename (public member function of std::numpunct<CharT>)

Protected member functions

do_decimal_point [virtual]	provides the character to use as decimal point (virtual protected member function of std::numpunct<CharT>)
do_thousands_sep [virtual]	provides the character to use as thousands separator (virtual protected member function of std::numpunct<CharT>)
do_grouping [virtual]	provides the numbers of digits between each pair of thousands separators (virtual protected member function of std::numpunct<CharT>)
do_truenamedo_falsename [virtual]	provides the string to use as the name of the boolean true and false (virtual protected member function of std::numpunct<CharT>)

Member objects

static std::locale::id id

id of the locale (public member object)

Example

This example demonistrates how to apply numeric punctuation rules of another language without changing the rest of the locale.

Run this code

#include <iostream>
#include <locale>
int main()
{
    const double number = 1000.25;
    std::wcout << L"default locale: " << number << L'\n';
    std::wcout.imbue(std::locale(std::wcout.getloc(),
                                 new std::numpunct_byname<wchar_t>("ru_RU.UTF8")));
    std::wcout << L"default locale with russian numpunct: " << number << L'\n';
}

Output:

default locale: 1000.25
default locale with russian numpunct: 1 000,25

See also

numpunct

defines numeric punctuation rules (class template)