std::locale:: facet

Defined in header <locale>
class locale :: facet ;

std::locale::facet is the base class for facets. It provides a common base class so that locales could store pointers to the facets they implement in a single indexed container, and it abstracts support for facet reference counting.

Whenever a facet is added to a locale, the locale increments the reference count in the facet (through an implementation-specific mechanism). Whenever a locale is destructed or modified, it decrements the reference count in each facet it no longer implements. Whenever a facet's reference count becomes zero, the locale performs delete static_cast < std :: locale :: facet * > ( f ) ; where f is the pointer to the facet.

Contents 1 Facet class 2 Member functions 3 Example 4 Defect reports 5 See also

Facet class

A class is a facet if

• it is publicly derived from another facet, or
• it is a class derived from std::locale::facet and contains a publicly accessible declaration as follows:

static :: std:: locale :: id id ;

Member functions

(constructor)	constructs a new facet with specified reference count (protected member function)
operator=	the copy assignment operator is deleted (protected member function)
(destructor) [virtual]	the destructor is protected virtual (virtual protected member function)

Example

This section is incomplete Reason: no example

Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

DR	Applied to	Behavior as published	Correct behavior
LWG 2694	C++98	the definition of 'facet' was removed by the resolution of LWG issue 436	added the definition back

See also

id	the facet index type: each facet class must declare or inherit a public static member of this type (class)