Closures? It would most likely be a frustrating and unrewarding one, but sure.

One thing I would like in C is a more programmable preprocessor. C++ templates are on to something useful -- metaprogramming removes some of the drudgery from writing fast native code. Templates are fatally flawed, though. I think it may be possible to get some of the benefits from a smarter preprocessor -- if it was done conservatively in the C style.