How is <tgmath.h> implemented?

Question

C doesn't have (to the best of my knowledge) overloading or templates, right? So how can a set of type-agnostic functions with the same name exist in plain ol' C? The usual compile-time trickery would involve a whole bunch of macros, wouldn't it?

Answer 1

There's a great explanation of how it works in GCC here.

Also, if anyone can solve the medium-difficulty exercise, I'd love to know the answer.