use_facet (3C++std) - Tru64 UNIX
Standard C++ LibraryCopyright 1996, Rogue Wave Software, Inc.
NAME
use_facet - Template function used to obtain a facet.
SYNOPSIS
#include <locale>
template <class Facet> const Facet& use_facet(const locale&);
DESCRIPTION
use_facet returns a reference to the corresponding facet contained in the
locale argument. You specify the facet type be explicitly providing the
template parameter (See the example below). If that facet is not present
then use_facet throws bad_cast. Otherwise, the reference will remain valid
for as long as any copy of the locale exists.
Note that if your compiler cannot overload function templates on return
type then you'll need to use an alternate use_facet template. The
alternate template takes an additional argument that's a pointer to the
type of facet you want to extract from the locale. The declaration looks
like this:
template <class Facet>
const Facet& use_facet(const locale&, Facet*);
The example below shows the use of both variations of use_facet.
EXAMPLE
//
// usefacet.cpp
//
#include <iostream>
int main ()
{
using namespace std;
locale loc;
// Get a ctype facet
const ctype<char>& ct =
#ifndef _RWSTD_NO_TEMPLATE_ON_RETURN_TYPE
use_facet<ctype<char> >(loc);
#else
use_facet(loc,(ctype<char>*)0);
#endif
cout << 'a' << ct.toupper('c') << endl;
return 0;
}
SEE ALSO
locale, facets, has_facet
privacy and legal statement