用C语言实现面向对象的多态

#include <stdio.h>

typedef void(*Draw)();
typedef struct 
{
	Draw draw;
}Shape;

typedef struct 
{
	Shape shape;
	int radius;
}Circle;

typedef struct 
{
	Shape shape;
	int length;
	int width;
}Rectangle;

void drawCircle() 
{
	printf("Drawing a circle\n");
}

void drawRectangle() 
{
	printf("Drawing a rectangle\n");
}

int main(void) 
{
	Circle circle;
	circle.shape.draw = drawCircle;
	circle.radius = 2;

	Rectangle rectangle;
	rectangle.shape.draw = drawRectangle;
	rectangle.length = 3;
	rectangle.width = 2;

	Shape* shape[] = { (Shape*)&circle ,(Shape*)&rectangle};
	for (int i = 0; i < sizeof(shape) / sizeof(shape[0]); i++) 
	{
		shape[i]->draw();
	}
	
	return 0;
}

运行结果