export interface LRUCacheOptions {
    /** Time to live in milliseconds, must be a non-zero positive number */
    ttl?: number;
}
export declare class LRUCache {
    private readonly capacity;
    private readonly options;
    /*!
     * The cache is a stack where recently used items are moved to the top of the stack.
     *
     * `top` - The most recently used item in the cache
     * `bottom` - The least recently used item in the cache
     * `downward` - The earlier item in the cache
     * `upward` - The recent item in the cache
     */
    private top;
    private bottom;
    private downward;
    private upward;
    private deletedSize;
    private deleted;
    private size;
    private keys;
    private ttls;
    private values;
    private items;
    constructor(capacity: number, options?: LRUCacheOptions);
    private static getTypedArray;
    private splayOnTop;
    private validateTTL;
    clear(): void;
    set<T>(key: string, value: T): LRUCache;
    has(key: string): boolean;
    get<T>(key: string): T | undefined;
    peek<T>(key: string): T | undefined;
    remove<T>(key: string): T | undefined;
}