C++ 虚函数表

C++中，通过虚函数表，可以访问基类的私有成员函数：

#include <iostream>

using namespace std;

class Base{

private:
    virtual void f() {cout << "Base::f" << endl;}
};

class Derive : Base{
};

typedef void(*Fun) (void);

int main() {

Base b;
Fun pFun = NULL;
cout << "virtual table's address is " << (int *) (&b) << endl;
cout << "the first func's address of virtual table is " << (int *) * (int *) (&b) << endl;

Derive d;

pFun = (Fun) * ((int*) * (int*) (&d) + 0);
pFun();
// delete pFun;  // can't delete a function pointer

return 0;

}

Reference : http://blog.csdn.net/hairetz/archive/2009/04/29/4137000.aspx