There was a long discussion about shared_mutex et al, and that was great. I don't want to start it all over again, but I was just wondering about the name: - I agree that 'reader writer', while known, might not be the best basis for a name - 'shared' is part of the answer but - aren't the terms 'shared' and 'mutual exclusion' (as in 'mutex'), well, mutually exclusive? ie somewhat contradicting? also, maybe 'shareable' is better than 'shared'? (other than an argument over whether it should have an 'e' stuck in the middle there or not) so how about: 'sharable_exclusion' (still sounds contradictory?) (sharex?) 'access_controller' - doesn't use known terminology, but is closer to what is really going on - it controls access to a resource. or 'shareable_access'? or ? shared_or_exclusive_access is probably the 'truest' description (and closest to reader_writer, as it does list both 'sides of the coin'), but a bit wordy... Tony