std::numpunct_byname

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

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

Protected member functions

[virtual]
 provides the character to use as decimal point
(virtual protected member function of std::numpunct<CharT>)
[virtual]
 provides the character to use as thousands separator
(virtual protected member function of std::numpunct<CharT>)
[virtual]
 provides the numbers of digits between each pair of thousands separators
(virtual protected member function of std::numpunct<CharT>)
[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.

#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

defines numeric punctuation rules
(class template)

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