I'm trying to summarize the renaming suggestions so they do not get lost. Here's my current list: The format is: current name ------------ suggestion 1 suggestion 2 ... unique_lock<Mutex> ------------------ exclusive_lock<Mutex> The boost name is Mutex::scoped_lock unique_lock<Mutex>::owns() -------------------------- owned() owns_lock() held() holds_lock() The boost name is locked() try_to_lock ----------- immediate The boost name is true defer_lock ---------- deferred Boost doesn't have this functionality accept_ownership ---------------- prelocked Boost doesn't have this functionality Have I missed any "renaming" suggestions? Comments pro or con on any of the above? My current feeling is that exclusive_lock has strong support, and I have no problem with that one myself. I'm not quite sure which of the owns() substitutes is the current front runner (holds_lock?). My only concern with this decision is that the name we choose should clearly not be ambiguous with "referencing a mutex". And the name should also not be ambiguous with asking if the mutex is locked (it may be locked by another thread). "try_lock" or "trylock" is a well known term. I fear "immediate" is not a good substitute as it does not imply to me that a "try_lock" is going to be performed. The existing "try_to_lock" is a compromise to avoid conflicts with a namespace-scope try_lock function. "try" would be nice, but is a keyword. I have no opinion on the last two (defer_lock, accept_ownership). -Howard