-- | /O(min(n,W))/. Is the key not a member of the map?
notMember :: Key -> IntMap a -> Bool
notMember k (IntMap m) = W.notMember (i2w k) m
notMember :: Key -> IntMap a -> Bool
notMember k (IntMap m) = W.notMember (i2w k) m
notMember k (IntMap m) = W.notMember (i2w k) m