why I can access private method from outside in C++? [duplicate]

Question

Possible Duplicate:
Why is it allowed to call derived class' private virtual method via pointer of base class?

Recently, I met a strange question, plz refer to following code:

#include <iostream>

using namespace std;

class A
{
    public:
        virtual void disp() {
            cout<<"A disp"<<endl;
        }

};

class B : public A
{
    private:
        void disp() {
            cout<<"B disp"<<endl;
        }
};

int main()
{
    A a;
    a.disp();

    A *b = new B();
    b->disp();
}

and the output is:

A disp
B disp

I'm wondering why pointer b can access disp()? It's private! Isn't it?

Answer 1

disp() is public since you're calling it through an A* and disp() is declared as public in A. Since it is virtual, B's version of disp gets called, but that doesn't affect whether it's public or private.