C++ Operator Ambiguity
- by Scott
Forgive me, for I am fairly new to C++, but I am having some trouble regarding operator ambiguity. I think it is compiler-specific, for the code compiled on my desktop. However, it fails to compile on my laptop. I think I know what's going wrong, but I don't see an elegant way around it. Please let me know if I am making an obvious mistake. Anyhow, here's what I'm trying to do:
I have made my own vector class called Vector4 which looks something like this:
class Vector4
{
private:
GLfloat vector[4];
...
}
Then I have these operators, which are causing the problem:
operator GLfloat* () { return vector; }
operator const GLfloat* () const { return vector; }
GLfloat& operator [] (const size_t i) { return vector[i]; }
const GLfloat& operator [] (const size_t i) const { return vector[i]; }
I have the conversion operator so that I can pass an instance of my Vector4 class to glVertex3fv, and I have subscripting for obvious reasons. However, calls that involve subscripting the Vector4 become ambiguous to the compiler:
enum {x, y, z, w}
Vector4 v(1.0, 2.0, 3.0, 4.0);
glTranslatef(v[x], v[y], v[z]);
Here are the candidates:
candidate 1: const GLfloat& Vector4:: operator[](size_t) const
candidate 2: operator[](const GLfloat*, int) <built-in>
Why would it try to convert my Vector4 to a GLfloat* first when the subscript operator is already defined on Vector4? Is there a simple way around this that doesn't involve typecasting? Am I just making a silly mistake? Thanks for any help in advance.
