import Optional from "./Optional";
/**
 * A Least Recently Used (LRU) Cache implementation with a fixed capacity.
 *
 * @template Key - The type of keys stored in the cache.
 * @template Value - The type of values stored in the cache.
 */
export default class LRUCache<Key, Value> {
    private readonly capacity;
    private cache;
    private usageOrder;
    private objectPool;
    private evictionCallback;
    /**
     * Create an LRUCache instance with a specified capacity.
     *
     * @param {number} capacity - The maximum number of entries the cache can hold.
     */
    constructor(capacity: number);
    /**
     * Retrieve a value from the cache based on the provided key.
     * Moves the accessed item to the front of the usage order.
     *
     * @param {Key} key - The key for the desired value.
     * @returns {Value | undefined} - The value associated with the key, or undefined if not found.
     */
    get(key: Key): Optional<Value>;
    /**
     * Add a key-value pair to the cache. If the cache exceeds capacity, the least recently used item is evicted.
     * Moves the added or accessed item to the front of the usage order.
     *
     * @param {Key} key - The key for the new item.
     * @param {Value} value - The value associated with the key.
     */
    put(key: Key, value: Value): void;
    /**
     * Add multiple key-value pairs to the cache. If the cache exceeds capacity, the least recently used items are evicted.
     * Moves the added or accessed items to the front of the usage order.
     *
     * @param {[Key, Value][]} entries - An array of key-value pairs to add to the cache.
     */
    putAll(entries: [Key, Value][]): void;
    /**
     * Clear all entries from the cache.
     */
    clear(): void;
    /**
     * Get an array of all keys currently in the cache.
     *
     * @returns {Key[]} - An array of keys in the cache.
     */
    getAllKeys(): Key[];
    /**
     * Get an array of all values currently in the cache.
     *
     * @returns {Value[]} - An array of values in the cache.
     */
    getAllValues(): Value[];
    /**
     * Get a generator yielding all entries (key-value pairs) in the cache.
     *
     * @yields {[Key, Value]} - A key-value pair from the cache.
     */
    entries(): Generator<[Key, Value]>;
    /**
     * Set a callback function to be called when an item is evicted from the cache.
     *
     * @param {(key: Key, value: Value) => void} callback - The callback function.
     */
    setEvictionCallback(callback: (key: Key, value: Value) => void): void;
    /**
     * Remove an item from the cache based on the provided key.
     *
     * @param {Key} key - The key of the item to remove.
     * @returns {boolean} - True if the item was removed, false if the key was not found.
     */
    remove(key: Key): boolean;
}