/**
 * A Least Recently Used (LRU) Cache implementation with a fixed capacity.
 * Provides O(1) lookup, insertion, and removal.
 *
 * @template Key - The type of keys stored in the cache.
 * @template Value - The type of values stored in the cache.
 */
export declare class LRUCache<Key, Value> {
    private readonly capacity;
    private cache;
    private nodes;
    private usageOrder;
    private evictionCallback;
    /**
     * @param capacity The maximum number of entries the cache can hold.
     */
    constructor(capacity: number);
    /**
     * Retrieve a value from the cache.
     * Moves the accessed item to the front of the usage order.
     *
     * @param key The key to look up.
     * @returns The value associated with the key, or undefined if not found.
     */
    get: (key: Key) => Value | undefined;
    /**
     * Add or update a key-value pair.
     * If adding the item causes the cache to exceed capacity, evicts the least recently used item.
     *
     * @param key The key.
     * @param value The value.
     */
    put: (key: Key, value: Value) => void;
    /**
     * Remove an item from the cache.
     *
     * @param key The key of the item to remove.
     * @returns True if the item was removed, false otherwise.
     */
    remove: (key: Key) => boolean;
    /**
     * Clear the cache of all entries.
     */
    clear: () => void;
    /**
     * Get all keys currently in the cache (order not guaranteed).
     */
    getAllKeys: () => Key[];
    /**
     * Get all values currently in the cache (order not guaranteed).
     */
    getAllValues: () => Value[];
    /**
     * Set a callback to be called when an item is evicted.
     *
     * @param callback The callback function.
     */
    setEvictionCallback: (callback: (key: Key, value: Value) => void) => void;
    /**
     * Get a generator yielding all entries in the cache (order not guaranteed).
     */
    entries(): Generator<[Key, Value]>;
}
export default LRUCache;