Message-ID: <m3zntzwlex.fsf@k242.linux.bogus>
p4raw-id: //depot/perl@17961
Restricts the given %hash's set of keys to @keys. If @keys is not
given it restricts it to its current keyset. No more keys can be
added. delete() and exists() will still work, but it does not effect
-the set of allowed keys.
+the set of allowed keys. B<Note>: the current implementation does not
+allow you to bless() the resulting hash, so if you want to use
+lock_keys() for an object, you need to bless it prior to locking it.
unlock_keys(%hash);