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std::numpunct_byname - cppreference.com

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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.

Specializations

The standard library is guaranteed to provide the following specializations:

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 character I/O

Nested types

Type Definition
char_type CharT
string_type std::basic_string<CharT>

Member functions

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

Nested types

Type Definition
char_type CharT
string_type std::basic_string<CharT>

Data members

Member Description
std::locale::id id [static] the identifier of the facet

Member functions

invokes do_decimal_point
(public member function of std::numpunct<CharT>) [edit]
invokes do_thousands_sep
(public member function of std::numpunct<CharT>) [edit]
invokes do_grouping
(public member function of std::numpunct<CharT>) [edit]
invokes do_truename or do_falsename
(public member function of std::numpunct<CharT>) [edit]

Protected member functions

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

Example

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

#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