c++动态绑定

#include<iostream>
using namespace std;
class b{
public:
	virtual void fun()
	{
		cout<<"我来自b"<<endl;
	}
};
class d:public b{
public:
	void fun()
	{
		cout<<"我来自d"<<endl;
	}
};
int main()
{
	d x;
	b*pb = &x;
	pb->fun();
	d*pd = &x;
	pd->fun();
	return 0;
}