[Boost-users] Sequence of Types, What For?

I've just finished reading C++ Template Metaprogramming again. I just don't get it. Why would someone use a type container? I have used enable_if, along with some of the logic functions for managing an overload set. Otherwise, I'm clueless. I'd really like a reference to an MPL primer or some case studies. Too much pain with very little gain. Time to ask for help. Rereading this, it sounds negative. Really, I think the MPL is really cool! terry