std::locale::id

From Cppreference

The class std::locale::id provides implementation-specific identification of a locale facet. Each class derived from std::locale::facet must have a public static member of type std::locale::id and each std::locale object maintains a list of facets it implements, indexed by their ids.

[edit] Member functions

[edit] Example

The following example shows how to construct a minimal custom facet.

#include <iostream>
#include <locale>
#include <iostream>
#include <locale>
struct myfacet : std::locale::facet
{
    myfacet(std::size_t refs=0) : facet(refs) {}
    static std::locale::id id;
};
std::locale::id myfacet::id;
int main()
{
    std::locale myloc(std::locale(), new myfacet);
    std::cout << "has_facet<myloc, myfacet> returns " << std::boolalpha
              << std::has_facet<myfacet>(myloc) << '\n';
}

Output:

has_facet<myloc, myfacet> returns true

[edit] See also