多继承无虚函数覆盖下的vftb排列

#include <iostream>
#include <string>
#include <vector>
#include <cctype>
using namespace std;
//多继承（无虚函数覆盖）
//1） 每个父类都有自己的虚表，有多少个父类就有多少个虚指针
//2） 子类的虚函数地址被放到了第一个父类的虚函数表中（排列顺序：先基类虚函数地址后子类虚函数地址）。（所谓的第一个父类是按照声明顺序来判断的）


class Base1
{
public:
	int x1;
	virtual void f1(){cout << "Base1::f" << endl;}
	virtual void g1(){cout << "Base1::g" << endl;}
	
};

class Base2
{
public:
	int x2;
	virtual void f2(){cout << "Base2::f" << endl;}
	virtual void g2(){cout << "Base2::g" << endl;}
	
};

class Base3
{
public:
	int x3;
	virtual void f3(){cout << "Base3::f" << endl;}
	virtual void g3(){cout << "Base3::g" << endl;}
	
};



class Derive:public Base1,public Base2,public Base3
{
public:
	int y;
	virtual void f(){cout << "Derive::f" << endl;}
	virtual void g(){cout << "Derive::g" << endl;}

};

typedef void (*Fun)();

int main()
{
	Fun pFun;
	

	Derive derive;
	Derive *de = &derive;
	
	//通过获取private虚函数指针，如下（(Fun)((*q)[3])）实现访问！
	void*** p = (void***)&derive;  

	cout<<*p<<endl;    // Base1Subobj 的 vptr,即指向Base1的虚函数表;
	cout<<**p<<endl;   // 指向Base1的f1虚函数
	cout<<*(*p+1)<<endl;
	cout<<*(*p+2)<<endl;  // 指向Derive的f虚函数
	cout<<*(*p+3)<<endl;  // 指向Derive的g虚函数
	
	pFun = (Fun)(**p);  //pFun为指向Base1::f1()的指针
	pFun();
	pFun = (Fun)(*(*p+1));  //pFun为指向Base1::g1()的指针
	pFun();
	pFun = (Fun)(*(*p+2));   //pFun为指向Derive::f()的指针
	pFun();
	pFun = (Fun)(*(*p+3));   //pFun为指向Derive::g()的指针
	pFun();
	

	system("pause");
	return 0;
}