With Concepts removed from C++Ox, people have been disappointed that this chance of making C++ template code generate better error messages was given up. Yet, there is no need for C++0x concepts in order to achieve this. Indeed, we have Boost.ConceptCheck that already makes things a bit simpler. Plus, by extending it with SFINAE for expressions, which allows to detect whether a type models a concept at compile-time, we get almost the same quality in error messages as with C++0x concepts. It would even allow to do concept-based overloading, but since SFINAE for expressions is not an universally supported feature, code shouldn't rely on that. Should all Boost libraries be modified in order to include concept checking, and should it become part of the programming policy? From what I can see, it seems most libraries don't make use of Boost.ConceptCheck at all.