OperatorOverloadExample

// Example program
#include <iostream>
#include <string>


class C {
private:
    int x = 10;

public:
    C() {
        std::cout << "Build C without x" << std::endl;

    }


    C(int _x) : x {_x } {
        std::cout << "Build C with x" << std::endl;
    }


    C sub(const C& c) const {
        int x_value = x - c.x;
        return  C(x_value);
    }

    int getX() const {
        return x;
    }


    C operator-() const {
        int new_x = -getX();
        return C(new_x);
    }

    C operator+() const {
        int new_x = getX();
        return C(new_x);
    }

    C& operator-=(const C& c) {
        x -= c.x;
        return *this;
    }

    friend C operator+(const C& left, const C& right);
    friend C operator-(const C& left, const C& right);


};

C operator+(const C& left, const C& right) {
    return C(left.getX() + right.getX());
}

C operator-(const C& left, const C& right) {
    return C(left.getX() - right.getX());
}

int main()
{
    C a;
    C b;

    auto var = a + b;

    std::cout << var.getX() << std::endl;
    var -= a;
    std::cout << var.getX() << std::endl;
}