Pass member OR non-member function pointers as parameters

Question

I have a struct called Foo which contains a function that calls whatever method it is passed and returns the value.

struct Foo
{
    unsigned char fooFunc(unsigned char param, unsigned char(getValueMethod)(const unsigned char))
    {
        return getValueMethod(param);
    }
};

I have a method called barFunc...

static unsigned char barFunc(const unsigned char paramA)
{
    return paramA * 2;
}

...which can be nicely passed to fooFunc

Foo foo1;
foo1.fooFunc(10, &barFunc);

But I also want fooFunc to accept member functions, like bazFunc....

struct Baz
{
    unsigned char bazFunc(const unsigned char paramB)
    {
        return paramB * 3;
    }
};

...to be called like this...

Foo foo2;
Baz baz;
foo2.fooFunc(10, ?????);

...but that isn't valid.

Everything I have found on the subject of passing member functions as parameters talks about knowing what class the object comes from before it is called, which means I would have to create 2 functions instead of one.

Is there a way I haven't found yet, which would require only 1 fooFunc method but would support non-member and member functions?

Answer 1

post c++11, as per other answers

pre c++11:

#include <iostream>
#include <functional>


using namespace std;

struct foo_holder {

    template<class T>
    unsigned char foo(unsigned char v, T f) {
        return f(v);
    }

};

unsigned char bar(unsigned char param) {
    return param * 2;
}

struct baz {
    unsigned char bar(unsigned char param) {
        return param * 3;
    }
};

int main()
{
   cout << "Hello World" << endl; 

   foo_holder f;
   baz b;

   cout << static_cast<int>(
    f.foo(6, bar)
    ) << endl;

   cout << static_cast<int>(
    f.foo(6, std::bind1st(std::mem_fun(&baz::bar), &b))
    ) << endl;

   return 0;
}