Re: [boost] [contract] concepts: pseudo-signatures vs. usage patterns

Can we write down pros and cons for concepts implemented via pseudo-signatures (C++0x-like and Boost.Generic) vs. usage patterns (N3351 and Boost.Contract)?

I think it would be more productive to start writing concepts in whatever system seems appropriate. Pick a library; write the concepts and their requirements in a way that feels natural to you. Don't forget the semantics. Figure out what you need to say, and try to find the most effective and least verbose way to say it. Try writing it another way. Maybe you'll end up with different ideas that either use-patterns or pseudo-signatures. It's more important to know the range of things that need to be said than how to say them.