클래스 Circle 참조에 의한 호출

#include <iostream>
using namespace std;

void increaseBy(Circle& a, Circle b);

class Circle
{
private:
	int radius;
public:
	Circle(int r) { radius = r; }
	int getRadius() { return radius; }
	void setRadius(int r) { radius = r; }
	void show() { cout << "반지름이 " << radius << "인 원" << endl; }
};


int main()
{
	cout << "2018305065 전유정" << endl;

	Circle x(10), y(5);
	increaseBy(x, y);
	x.show();
}

void increaseBy(Circle& a, Circle b)
{
	int r = a.getRadius() + b.getRadius();
	a.setRadius(r);
}