Thread: Pointers to Class Member Functions

I am working on a class that holds a vector of class member functions. While normal function pointers a quite easy to implement I have discovered that using pointers to member functions take a bit more thought.

My first attempt:

Code:

typedef void *pData;
typedef void(*pFunction)(pData);
class MyClass1
{
public:
    MyClass1() { m_a = 5; m_b = 10; }
    ~MyClass1() { }
    void Go();
    static void f1(pData d) { std::cout<<"Member Function 1.  a = " <<static_cast<MyClass1*>(d)->m_a <<"\n"; }
    static void f2(pData d) { std::cout<<"Member Function 2.  b = " <<static_cast<MyClass1*>(d)->m_b <<"\n"; }
private:
    std::vector<pFunction> m_VecFunc;
    int                    m_a, m_b;
};
void MyClass1::Go()
{
    m_VecFunc.push_back(&f1);
    m_VecFunc.push_back(&f2) ;
    std::vector<pFunction>::iterator iter;
    for (iter = m_VecFunc.begin(); iter != m_VecFunc.end(); ++iter)
    {
        (*iter)(this);
    }
    return;
}

This works quite well. The only problem is that in order to access member variables I have to pass this to the function and cast it to a MyClass1 pointer before each call to a member variable.
I'm not sure I like this. While it works it seems like more work than it should be, having to remember to cast each member variable before I use it.

So then I came up with my second approach.

Code:

class MyClass2
{
public:
    MyClass2() { m_a = 5; m_b = 10; }
    ~MyClass2() { }
    void f1() { std::cout<<"Member Function 1.  a = " <<m_a <<"\n"; }
    void f2() { std::cout<<"Member Function 2.  b = " <<m_b <<"\n"; }
    void Go();
    void DoCallBack(pFunction f, pData x) { f(x); }  // calls f(x)
private:
    static void call_f1(pData d) { static_cast<MyClass2*>(d)->f1(); }
    static void call_f2(pData d) { static_cast<MyClass2*>(d)->f2(); }
    int                    m_a, m_b;
    std::vector<pFunction> m_VecFunc;
};
void MyClass2::Go()
{
    m_VecFunc.push_back(call_f1);
    m_VecFunc.push_back(call_f2);
    std::vector<pFunction>::iterator iter;
    for (iter = m_VecFunc.begin(); iter != m_VecFunc.end(); ++iter)
    {
        (*iter)(this);
    }
    return;
}

This also works quite well. I no longer have to cast each member variable before I can use it. The only problem now is that for each member function I want to take the address of, I have to have a second function just to call it. And I still have to pass this to the calling function.
I'm not sure I care for this either.

Is there a way of doing this so that I can directly use member variables without having to do any type casting?