ptr_fun

template<class Arg, class Result>
    pointer_to_unary_function<Arg, Result>
        ptr_fun(Result (*pf)(Arg));
template<class Arg1, class Arg2, class Result>
    pointer_to_binary_function<Arg1, Arg2, Result>
        ptr_fun(Result (*pf)(Arg1, Arg2));

The first template function returns pointer_to_unary_function<Arg, Result>(pf).

The second template function returns pointer_to_binary_function<Arg1, Arg2, Result>(pf).