These are some experinmental code snippets from "C Traps and Pitfalls" by Andrew Koenig. The original article is available online.
I wasn't aware of this epic article until jserv mentioned it in his online lecture, which is the most hardcore C progarmming lectures in Traditional Chinese. To follow his course, check [http://hackfoldr.org/dykc/] (http://hackfoldr.org/dykc/).
These are short excerpts from the article and I do NOT own the copy right.