std::locale::facet::facet (3) - Linux Man Pages
Defined in header <locale>
explicit facet( std::size_t refs = 0 ); (1)
facet(const facet&) = delete; (2)
1) creates a facet with starting reference count refs. If refs is non-zero, the facet will not be deleted when the last locale referencing it goes out of scope. A facet with static or dynamic storage duration should always be constructed with a non-zero refs.
2) copy constructor is deleted; std::locale::facet is not copyable.