head.h

关于如何用C语言编写重载的例子

 #include<iostream.h>
class MyGraph
{
public:
	virtual double area()=0;
};
class MyCircle:MyGraph
{
private:
	int centerX;
	int centerY;
	int radius;
public:
	MyCircle();
	double area();
	friend istream &operator>>(istream& is,MyCircle& circle);

};
class MyRectangle:MyGraph
{
private:
	int length;
	int width;
public:
	MyRectangle();
	double area();
	friend istream &operator>>(istream& is,MyRectangle &Rectangle);
};