这是《C／C++程序员实用大全》上面的源码

				#include 
				
				class Base 
				{
				 public:
				   void display(void) { cout 				};
				
				class Derived: public Base 
				{
				 public:
				   void display(void) { cout 				};
				
				void main(void)
				 {
				   Derived my_class;
				
				   my_class.display();
				 }