C++ 虚函数表解析（转）——转自陈皓

#include<iostream>
using namespace std;

//基类
class Base {
public:
	virtual void f() { cout << "Base::f" << endl; }
	virtual void g() { cout << "Base::g" << endl; }
	virtual void h() { cout << "Base::h" << endl; }

};

//无虚函数覆盖的子类
class derive:public Base
{
	virtual void f1() { cout << "derive::f1" << endl; }
	virtual void g1() { cout << "derive::g1" << endl; }
	virtual void h1() { cout << "derive::h1" << endl; }
};

//有虚函数覆盖
class derive2:public Base
{
	virtual void f() { cout << "derive2::f" << endl; }
	virtual void g() { cout << "derive2::g" << endl; }
	virtual void h() { cout << "derive2::h" << endl; }
};

int main()
{
	//基类里虚函数
	/*
	typedef void(*Fun)(void);//表示定义一个函数指针类型
	Base b;
	Fun pFun = NULL;
	cout << "虚函数表地址：" << (int*)(&b) << endl;
	cout << "虚函数表 — 第一个函数地址：" << (int*)*(int*)(&b) << endl;
	// Invoke the first virtual function 
	pFun = (Fun)*((int*)*(int*)(&b));//加上后面的（Fun）*是将int*强制转换为函数指针
	pFun();
	*/

	//无虚函数覆盖
	/*
	typedef void(*Fun)(void);
	derive c;
	Fun pFun=NULL;
	cout<<(int*)*(int*)(&c)+0<<endl;
	pFun=(Fun)*((int*)*(int*)(&c)+0);
	pFun();
	cout<<(int*)*(int*)(&c)+1<<endl;
	pFun=(Fun)*((int*)*(int*)(&c)+1);
	pFun();
	cout<<(int*)*(int*)(&c)+2<<endl;
	pFun=(Fun)*((int*)*(int*)(&c)+2);
	pFun();
	cout<<(int*)*(int*)(&c)+3<<endl;
	pFun=(Fun)*((int*)*(int*)(&c)+3);
	pFun();
	*/

	//


	system("pause");
	return 1;
}