第六章课后练习题（P273_3_3）

#include<iostream>
using namespace std;

class Base
{
public:
virtual void display() = 0;
};

class Dervied1:public Base
{
public:
void display()
{
cout<<"Dervied1 called!"<<endl;
}
};

class Dervied2:public Base
{
public:
void display()
{
cout<<"Dervied2 called!"<<endl;
}
};

void fun(Base *p)
{
p->display();
}

int main()
{
Dervied1 b1;
Dervied2 b2;
Base *p = &b1;
fun(p);
p = &b2;
fun(p);
return 0;
}