Returns true if the map is empty. */

Returns true if the map is empty in the current context. */

Returns true if the queue is empty in the current context. */

Returns true if the queue is empty in the current context. */

* Returns an iterator to the end of the map. * Acts like a hash_map::const_iterator. */

* Enqueues an element in the current context. * Returns its index in the queue. */

The hard way is this: