C++ Operator Overloading Int Types

Question

I'm working on a fractions class in C++ and have defined the addition of a frac and an int in the new class, but it requires them to show up in that order: frac + int. Is there a way to overload + in the Int type such that we have a function that accepts a frac and outputs a frac? Or is there a way to reverse the order in the new class?

I already have frac + frac and frac += frac operators defined. The two functions in question are:

frac operator+=(int b)
{
    frac c = { n + b*d, d };
    return c;
}

frac operator+(int b)
{
    frac c = *this;
    frac d = { b };
    c += d;
    return c;
}

something like this:

frac int::operator+=(frac& b)
{
    frac c = { this * b.den() + b.num(), b.den() };
    return c;
}

But I'm not sure how to actually accomplish this.

---

Code from question below:

frac &operator+=(frac b)
{
    frac c = { n * b.den() + b.num() * d, d * b.den() };
    n = c.num();
    d = c.den();
    return *this;
}

frac operator+(int a, frac b)
{
    return frac{ a } += b;
}

Answer 1

Well there's no class int so you can't do what you suggested but the easy thing is to declare a function like this (inside your class)

 friend frac operator+(int a, frac b);

That way this function will be called when the other order is used. Edit: you need to use the friendspecifier because the function isn't in the class, I forgot about that.