C++ preprocessor conditional parameter

Question

Please note C++03! any C++11 solutions are not good for me, but do post them just for knowledge sake.

I know the preprocessor can do things like:

#de         


        

Answer 1

Some answers here were better than others. The one I accepted was posted by Christian Kiewiet in a comment, but it was the most accurate for my purpose. Here is the expanded version:

useCases.h

enum UseCases{
    useCase1=0,
    useCase2,
    useCaseNumber//always last for iterations
} 

specializer.h

#include "useCases.h"