명품 C++ Programming 실습문제 7장 7번

#include <iostream>
using namespace std;
 
class Circle {
    int radius;
public:
    Circle(int radius = 0) { this->radius = radius; }
    void show() { cout << "radius = " << radius << " 인 원" << '\n'; }
    Circle operator++();
    Circle operator++(int x);
};
 
Circle Circle::operator++() {
    radius++;
    return *this;
}
 
Circle Circle::operator++(int x) {
    Circle tmp = *this;
    radius++;
    return tmp;
}
 
int main() {
    Circle a(5), b(4);
    ++a;
    b = a++;
    a.show();
    b.show();
}