A multimap container supports equivalent keys that may contain multiple copies of the same key value. Multimap provides for fast retrieval of values of another type based on the keys.
Multimap supports bidirectional iterators.
The multimap satisfies all of the requirements of a container, reversible container and associative containers.
Multimap supports the a_eq operations but not the a_uniq operations.
For a multimap<Key,T> the key_type is Key and the value_type is pair<const Key,T>