Question

In a project of mine, I’m writing a wrapper for std::vector. I’m doing this because I am using homogeneous coordinates and for some operations it’s just easier to temporarily ‘forget’ the fourth coordinate.

Now I stumbled upon a problem. I have loads of assignments like the following:

    Vector v;
    v(0) = 5;
    v(1) = 6;

and so on. I also want to do the following:

   double x;
   x = v(0);

For that last thing, I can overload the () operator, but how would implement the first thing? (the zero and one being an index).

Answer 1

Just return reference.

class Vector
{
  int data[4];
  int & operator() (int index) { return data[index]; }
};