On Sat, 14 Sep 2013 14:33:56 +0900 Larry Hastings <larry@hastings.org> wrote:Whenever I read a discussion about the dict, I always wonder whether the same thing applies to a set. Have you considered the utility of a TransformSet? Or is it YAGNI?Well, a TransformSet is like a normal dict, you just need to call the transformation function yourself when inserting the keys.