How to resolve ambiguity in overloaded functions using SFINAE

Question

I have an incredibly exciting library that can translate points: it should work with any point types

template
auto translate_point(T &p, int x         


        

Answer 1

With SFINAE, I would do something like this:

template
auto translate_point(T &p, int x, int y) -> decltype(p[0], void())
{
    p[0] += x;
    p[1] += y;
}

template::value>
auto translate_point(T &p, int x, int y) -> decltype(p.x, p.y, void())
{
    p.x += x;
    p.y += y;
}

By doing this, when T = (class with StupidPoint as base class), the second overload will be called.

But it is easier with a simple overload, as pointed out by m.s.