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Defined in header <locale>

template< class charT >
class numpunct;

The facet std::numpunct encapsulates numeric punctuation preferences. Stream I/O operations use std::numpunct through std::num_get and std::num_put for parsing numeric input and formatting numeric output.

Two specializations are provided by the standard library

Defined in header <locale>
std::numpunct<char> provides equivalents of the "C" locale preferences
std::numpunct<wchar_t> provides wide character equivalents of the "C" locale preferences


[edit] Member types

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

[edit] Member objects

Member name Type
id (static) std::locale::id

[edit] Member functions

constructs a new numpunct facet
(public member function)
destructs a numpunct facet
(protected member function)
invokes do_decimal_point
(public member function)
invokes do_thousands_sep
(public member function)
invokes do_grouping
(public member function)
invokes do_truename
(public member function)
invokes do_falsename
(public member function)
the following protected member functions can be overridden in a user-defined facet derived from numpunct
do_decimal_point [virtual]
provides the character to use as decimal point
(virtual protected member function)
do_thousands_sep [virtual]
provides the character to use as thousands separator
(virtual protected member function)
do_grouping [virtual]
provides the numbers of digits between each pair of thousands separators
(virtual protected member function)
do_truename [virtual]
provides the string to use as the name of the boolean true
(virtual protected member function)
do_falsename [virtual]
provides the string to use as the name of the boolean false
(virtual protected member function)

[edit] Example

The following example changes the string representations of true and false

#include <iostream>
#include <locale>
struct french_bool : std::numpunct<char> {
    string_type do_truename() const { return "oui"; }
    string_type do_falsename() const { return "non"; }
int main()
    std::cout << "default locale: "
              << std::boolalpha << true << ", " << false << '\n';
    std::cout.imbue(std::locale(std::cout.getloc(), new french_bool()));
    std::cout << "locale with modified numpunct: "
              << std::boolalpha << true << ", " << false << '\n';


default locale: true, false
locale with modified numpunct: oui, non

[edit] See also

creates a numpunct facet for the named locale
(class template)