Functions with return values (C++)

Question

When main() calls a function which has a return value of some datatype ( primitive or user-defined ) , the statement in which the function is called is \'usually\' an assign

Answer 1

Another solution is to use operator + in global scope but as a friend of your class:

class complex
{
    // ...

public:

    // ...

    friend complex operator +(const complex &c1, const complex &c2)
    {
        complex c;
        c.real = c1.real + c2.real;
        c.imag = c1.imag + c2.imag;
        return c;
    }

    // ...

};

Using this technique you can also use an integer as argument (at the lhs) by adding:

    friend complex operator +(const int n, const complex &c)
    {
        complex c;
        c.real = n + c.real;
        c.imag = c.imag;
        return c;
    }

    friend complex operator +(const complex &c, const int n)
    {
        complex c;
        c.real = c.real + n;
        c.imag = c.imag;
        return c;
    }

So now you can also do

 complex c1, c2, c3;
 c3 = 1 + c2 + 8 + c1 + 2;

and your class is missing a (virtual) destructor, I would also make the member variables protected instead of private :)