Curiously Recurring Template Patterns

CRTP can be useful for many things like allowing objects to be counted.

I actually use it with all of my game objects as it allows me to easily implement a way to track all the objects of a particular type that automatically adds and removes them from the list as needed.

PS: As I continue to post you might notice that I'll often reference other sites (such a wikipedia, I might reference C++ FAQ lite or cplusplus.com)