Why doesn't STL have a pointer to member function adaptor, such as:

template <class Arg1, class Arg2, class Result>
class pointer_to_member_function : public binary_function<Arg1,Arg2,Result>
{
  public:
    explicit pointer_to_binary_function(Result (Arg1::*f)(Arg2)) : f(f)
      {}

    Result operator()(const Arg1& x, const Arg2& y) const
      { return x.*pf(y); }
};

template <class Arg1, class Arg2, class Result>
pointer_to_member_function<Arg1,Arg2,Result> ptr_fun(Result (Arg1::*f)(Arg2))
{
  pointer_to_member_function<Arg1,Arg2,Result>(f);
}

Of course, there also could a pointer_to_unary_member_function, and a
pointer_to_void_member_function.

IMHO, this seems to be a very easy addition, as well as VERY useful
when you want to use anything in <algorithm>.  [I have wanted it many
times, and after adding it myself, I use it all the time.]

Brian Freyburger


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