std::use_facet

From cppreference.com
< cpp‎ | locale
Defined in header <locale>
template< class Facet >
const Facet& use_facet( const std::locale& loc );

Obtains a reference to a facet implemented by loc.

Parameters

loc - the locale object to query

Return value

Returns a reference to the facet. The reference returned by this function is valid as long as any std::locale object exists that implements Facet.

Exceptions

std::bad_cast if std::has_facet<Facet>(loc) == false.

Example

Display the 3-letter currency name used by the user's preferred locale

#include <iostream>
#include <locale>
 
int main()
{
    std::locale loc = std::locale(""); // user's preferred locale
    std::cout << "Your currency string is "
              << std::use_facet<std::moneypunct<char, true>>(loc).curr_symbol() << '\n';
}

Output:

Your currency string is USD

See also

set of polymorphic facets that encapsulate cultural differences
(class)
checks if a locale implements a specific facet
(function template)