class refusing to accept external function

[Blessman11]

I have got a weird error were my class is refusing to accept a function that has been declared externally outside the class.

Do I need some denotation that I am using an external function or should I declare this function as a friend? This function draw_ball doesn't access any private elements.

 void draw_ball() {
  glColor3f(0.6,0.3,0.);
  MyCircle2f(0.,0.,RadiusOfBall);
 }

class CLetter
{
public:
virtual void draw()const
{	draw_ball();
}
};

[hanst99]

Is the setup like that?

Because when draw_ball is actually under class CLetter, the compiler won't know what it is at compile time, which would cause errors. Other than that it could also be you put it in another namespace, in that case you'd have to use the scope operator.

[hamsterman]

There's nothing wrong with this code. What does the error say?