Defined in header <functional> template< class Arg, class Result >
std::pointer_to_unary_function<Arg,Result>
ptr_fun( Result (*f)(Arg) ); (1) (until C++17)(deprecated since C++11) template< class Arg1, class Arg2, class Result >
std::pointer_to_binary_function<Arg1,Arg2,Result>
ptr_fun( Result (*f)(Arg1, Arg2) ); (2) (until C++17)(deprecated since C++11)
Creates a function wrapper object (either std::pointer_to_unary_function or std::p