Hi, I have been reading the Test Tools docs. Would it be a good idea to add ConceptChecking to the list of alternative methods of reporting errors, in /test/doc/index.html#introduction ? A recent post on boost alluded to the fact that Concepts (ie What is a concept? ) can be difficult to understand. Well ... ConceptChecks are the medium for pinning down Concepts in C++ code and are probably the most effective means of error reporting at compile time, but are not used as much as they could be. The Boost Test Library would seem to be as good a place as any to promote them, which could help to remove some of the mystery. regards Andy Little