pointer_to_binary_function
template<class Arg1, class Arg2, class Result>
class pointer_to_binary_function
: public binary_function<Arg1, Arg2, Result> {
public:
explicit pointer_to_binary_function(
Result (*pfunc)(Arg1, Arg2));
Result operator()(const Arg1 left, const Arg2 right) const;
};The template class stores a copy of pfunc. It defines its member function operator() as returning (*pfunc)(left, right).