Function pointer to member function.

[TheFlyingFiddle]

I would like to get access to a member function pointer. Taking
the this* as
the first argument.

class Foo
{
    void bar(int a)
    {
       //do something awesome
    }
}

unittest
{
    Foo a = new Foo();
    Foo b = new Foo();

    auto fp = getFP!(Foo.bar);
    fp(a, 1); //Basically calls a.foo(1)
    fp(b, 1); //Basically calls b.foo(1)
}

How should i implement getFP above? Is it even possible?