#include <iostream>

class T {
    int i = 0;

public:
    explicit T(int i): i(i) {}; // 기본 생성자

    T operator+ (const T& t) const {
        T t_(i + t.i);
        return t_;
    }

    T(T& t) { // 복사 생성자
        std::cout << "copy called" << std::endl;
        i = t.i;
        std::cout << "constructor ended" << std::endl;
    }

    T(T&& t) noexcept { // 이동 생성자
        std::cout << "move called" << std::endl;
        i = t.i;
        std::cout << "constructor ended" << std::endl;
    }

    ~T() { // 소멸자
        std::cout << "destroyed" << std::endl;
    }
};

int main() {
    T t1(10);
    T t2(20);

    std::cout << "(1) ============" << std::endl;
    T&& t3 = t1 + t2;
    std::cout << std::endl;

    std::cout << "(2) ============" << std::endl;
    T t3_1 = t1 + t2;
    std::cout << std::endl;

    std::cout << "(3) ============" << std::endl;
    const T& t4 = t1 + t2;
    std::cout << std::endl;

    std::cout << "(4) ============" << std::endl;
    T& t5 = t1;
    std::cout << std::endl;

    std::cout << "(5) ============" << std::endl;
    T t5_1 = t1;
    std::cout << std::endl;

    std::cout << "code fin\n" << std::endl;

    return 0;
}