I kind of disagree here. .lock() has the following behavior:
panic() if the lock is already held by this thread - should never happen
error - if the current lock holder paniced
The second case is incredibly rare, so it’s one of the few cases where I think .unwrap() makes sense in production code. But it should be an option to handle it in robust code that should never go down. This is rare, but it’s not so rare that we should force all locks to exist in a context where we can recover from panics.
.try_unlock() should never exist because there should only be one way to release a lock: drop(). Having a way to maybe unlock a mutex adds a ton of issues. If we assume this was a typo, .try_lock() absolutely exists, and it’s for a non-blocking lock.