/*
CS371p: Quiz #20 (5 pts)
*/

/* -----------------------------------------------------------------------
1. Operators have the following properties.
   a. precedence
   b. associativity
   c. arity (number of arguments)
   d. lvalue / rvalue nature of the arguments or return
   Which of those properties can be changed when overloading the operator
   on a user type?
   (Maybe more than one.)
   (2 pts)

d.
*/

/* -----------------------------------------------------------------------
2. Define class Complex such that the program below works.
   The operator+() MUST call the operator+=().
   (2 pts)
*/

#include <cassert> // assert

template <typename T>
class Complex {
    private:
        T _r;
        T _i;

    public:
        Complex (const T& r = T(), const T& i = T()) :
                _r (r),
                _i (i)
            {}

        Complex& operator += (const Complex& rhs) {
            _r += rhs._r;
            _i += rhs._i;
            return *this;}

        const T& real () const {
            return _r;}

        const T& imag () const {
            return _i;}};

template <typename T>
Complex<T> operator + (Complex<T> lhs, const Complex<T>& rhs) {
    return lhs += rhs;}

int main () {
          Complex<int> x(2, 3);
    const Complex<int> y(4, 5);

    const Complex<int>& z = (x += y);
    assert(&z == &x);
    assert(z.real() == 6);
    assert(z.imag() == 8);

    Complex<int> t = y + z;
    assert(t.real() == 10);
    assert(t.imag() == 13);

    return 0;}