/**
 * @class Queue
 * @util
 */
declare class Queue {
    /**
     * The ordered collection of items held in the queue, where index 0 is the front.
     */
    items: unknown[];
    /**
     * Initializes the queue with an optional pre-populated array of items.
     */
    constructor(initial?: unknown[]);
    /**
     * Add new item or items at the back of the queue.
     *
     * @param {*} items An item to add.
     */
    enqueue(...items: unknown[]): void;
    /**
     * Remove the first element from the queue and returns it.
     *
     * @returns {*}
     */
    dequeue(): unknown;
    /**
     * Return the first element from the queue (without modification queue stack).
     *
     * @returns {*}
     */
    peek(): unknown;
    /**
     * Check if the queue is empty.
     *
     * @returns {boolean}
     */
    isEmpty(): boolean;
    /**
     * Return number of elements in the queue.
     *
     * @returns {number}
     */
    size(): number;
}
export default Queue;