C / C++ / MFC

class A   
{
    int val;
public:
    A() { val = 0; }
    A(int j) { val = j; }

    int aFun(int k) {val -= k; return val; }
};

typedef int (* func)(int );
class B
{
    func m_addr;
public:
    B(func param)
        : m_addr(param)
    {

    }
    void execute()
    {
        cout << m_addr(9) << endl;
    }
};

/* error C2355: 'this' : can only be referenced inside non-static member functions error C2064: term does not evaluate to a function taking 1 arguments class does not define an 'operator()' or a user defined conversion operator to a pointer-to-function or reference-to-function that takes appropriate number of arguments */
A a;
B b(A::aFun); 
b.execute();