[Boost-users] question about threading library

I want to use the boost threading library in an application. Looking through the documentation, I have a questions. a) in the examples I find "boost::mutex::scoped_lock" but I don't find this in the documentation. It looks like this is called "lock_guard". What should I be doing here. b) Its not clear to me how unique_lock(Lockable l) is different than using lock_gard(..) or scoped_lock. Robert Ramey