I'm all for extra documentation and we need it badly, because whole chunks of krita code are locked for changes because of the lack of it...

But when it comes to apidox, this isn't too helpful. It's better than nothing, but it still doesn't tell me why, when and how to use this class. It refers to something else, std::lock_guard, that in itself probably is unfamiliar to every krita coder and itself has (http://en.cppreference.com/w/cpp/thread/lock_guard) gobbledigook for apidox.