Same kind of thing, but typesafe:
https://github.com/FRRouting/frr/blob/master/lib/typesafe.h
https://github.com/FRRouting/frr/blob/master/doc/developer/l...
(disclaimer: it's my work.)
mine is better :)
And this one may be even "better" :)
https://github.com/tylov/STC