Yes, I know C has no function overloading (or optional parameters) of course. I didn't feel like writing it out twice though. The pattern is more useful when

Yes, I know C has no function overloading (or optional parameters) of course. I didn't feel like writing it out twice though. The pattern is more useful when there are more arguments to foo and you don't want to have bar(int a, int b, double c, foo * useme) and bar(int a, int b, double c) in the API.