Thanks to you too Tiago!

You touched upon something I meant to ask for. A name. unique_multilock
felt right at the time I started because it is supposed to be ju like a
unique_lock, only for multiple lockables.

Today we have lock_guard and it's multi mutex cousin scoped_lock.
With this proposal we'd have unique_lock and ...

Some candidates, other than unique_multilock:
unique_scoped_lock ("scoped" didn't feel right for this movable type)
unique_lock_set (the "set" part didn't feel right)

If anyone has an idea, please share!