Here's my code...

Code:

// Operators
inline Vector operator- (Vector v) const { return Vector(-v.X(), -v.Y()); }
inline bool operator== (Vector v, Vector u) const { return v.X() == u.X() && v.Y() == u.Y(); }
inline bool operator!= (Vector v, Vector u) const { return !(v == u); }
inline Vector operator+ (Vector v, Vector u) const { return Vector(v.X() + u.X(), v.Y() + u.Y()); }
inline Vector operator- (Vector v, Vector u) const { return Vector(v.X() - u.X(), v.Y() - u.Y()); }
inline Vector operator* (Vector v, int in) const { return Vector(v.X() * in, v.Y() * in); }
inline Vector operator/ (Vector v, int in) const { return Vector(v.X() / in, v.Y() / in); }

Here's the error: c:\my documents\pong16\vector.h(33) : error C2270: '-' : modifiers not allowed on nonmember functions

This error repeats for all the operators. I should note, this overloading is taking place outside of the class definition, but in the same file.