map package:unordered-containers

O(n) Transform this map by applying a function to every value.
O(n) Transform this set by applying a function to every value. The resulting set may be smaller than the source.
O(n) Transform this map by applying a function to every value and retaining only some of them.
O(n) Transform this map by applying a function to every value and retaining only some of them.
O(n) Transform this map by applying a function to every value.
A map from keys to values. A map cannot contain duplicate keys; each key can map to at most one value.
O(1) Convert from the equivalent HashMap.
O(1) Convert to the equivalent HashMap.