Many thanks for the quick replies. I admit I did the header guards in a bit of a hurry, so I will check into that.
I've understood the idea of passing the parameter by reference, and I agree with that. Guess I was too used to Java.
I performed a complete replacement of the code to accept this declaration:
Code:
bool CB_col(Wall & blck) const;
The main problem (C2061) remains, though.