[KMag]

You use a hash map, and make the linked list a linked list of hash entries. So, if you're using chaining (as opposed to the many variations on open addressing):

    class Entry<K,V> {
        Entry<K,V> younger;  // LRU doubly linked list
        Entry<K,V> older;    // LRU doubly linked list
        Entry<K,V> next;     // for hash map bucket chaining
        V value;
        K key;
    }

The naive solution using two separate data structures would look like:

    class MapEntry<K,V> {
        Entry<K,V> next;
        DoublyLinkedListEntry<MapEntry<K,V>> LruEntry;
        K key;
        V value;
    }

    class DoublyLinkedListEntry<T> {
        ListEntry<T> prev;
        LintEntry<T> next;
        T value;
    }