静态联编和动态联编初认识。

 1     #include <iostream>  
 2     using namespace std;  
 3     class shape{  
 4       public:  
 5         void virtual draw(){cout<<"I am shape"<<endl;}//这里设定了draw是虚函数  
 6         void fun(){draw();}  
 7     };  
 8     class circle:public shape{  
 9       public:  
10         void draw(){cout<<"I am circle"<<endl;}//虽然没有说明circle类中的draw是虚函数，但是circle其实继承了virtual性质  
11     };  
12     void main(){  
13         circle  oneshape;  
14         oneshape.fun();  
15     }