Nice. Let me just fill in a tip that I got from merlyn on how to make your eval's have nice messages. Just use a line directive in a comment as described at the end of perlsyn. See Class::FlyweightWrapper for an example where I do that. Any errors in the classes that I generate with eval there will appear with messages identifying clearly what the purpose of that eval is, and hopefully with enough information to be able to go in and figure out what is messed up in the eval that was called.