#include <iostream>using namespace std;class Base{public:    int m_base;    Base():m_base(20){}    virtual void vfBase_1()    {        cout << "This is in Base::vfBase_1()" << endl;    }    virtual void vfBase_2()    {        cout << "This is in Base::vfBase_2()" << endl;    }};class Derived : public virtual Base{public:    int m_derived;    Derived():m_derived(10){}    virtual void vfDerived()    {      cout << "This is in Derived::vfDerived()" << endl;    }    void vfBase_1()    {        cout << "This is in Derived::vfBase_1()" << endl;    }};typedef void (*VFun)(void);int main(void){    Derived d;    int **pVtab=NULL;    pVtab=(int**)&d;    cout << "The size of Base object = \t" << sizeof(Derived) << endl;    cout << endl;    cout<<"derived lst virtual function address: "<<(int*)(*((int*)(*(int*)&d) + 0))<<endl;    cout<<"derived lst virtual function result: ";    VFun pVF =(VFun)pVtab[0][0];    pVF();    cout<<endl;    cout<<"derived 2nd virtual function address: "<<(int*)(*((int*)(*(int*)&d) + 1))<<endl;    cout<<"derived 2nd virtual function result: ";    pVF = (VFun)pVtab[0][1];    pVF();    cout<<endl;    cout<<"virtual table end flags: "<<pVtab[0][2]<<endl;    cout<<endl;    cout<<"derived data member:";    cout<<(int)*((int*)&d+1)<<endl;    cout<<"base lst virtual function address: "<<(int*)pVtab[2][0]<<endl;    cout<<"base lst virtual function result: ";    pVF = (VFun)pVtab[2][0];    pVF();    cout<<endl;    //转换为int*就代表虚函数的地址    cout<<"base 2nd virtual function address: "<<(int*)(*((int*)(*((int*)&d+2)) + 1))<<endl;    cout<<"base 2nd virtual function result: ";    //转换为vFun代表虚函数的函数指针    pVF = (VFun)(*((int*)(*((int*)&d+2)) + 1));    pVF();    cout<<endl;    cout<<"virtual table end flags: "<<(*((int*)(*((int*)&d+2)) + 2))<<endl;    cout<<endl;    cout<<"base data member:";    cout<<(int)pVtab[3]<<endl;    return 0;}