/**
 * A queue collection that supports FIFO operations.
 *
 * @public
 */
export default class Queue {
    /**
     * Adds an item to the end of the queue.
     *
     * @public
     * @param {*} item - The item to add.
     * @returns {*} The item added to the queue.
     */
    public enqueue(item: any): any;
    /**
     * Removes the next item from the queue and returns it. Throws if the queue is empty.
     *
     * @public
     * @returns {*} The item removed from the queue.
     * @throws {Error} If the queue is empty.
     */
    public dequeue(): any;
    /**
     * Returns the next item in the queue without removing it.
     *
     * @public
     * @returns {*} The next item in the queue.
     * @throws {Error} If the queue is empty.
     */
    public peek(): any;
    /**
     * Indicates whether the queue is empty.
     *
     * @public
     * @returns {boolean} True if the queue is empty; otherwise, false.
     */
    public empty(): boolean;
    /**
     * Runs an action on each item in the queue.
     *
     * @public
     * @param {Function} action - The action to run.
     */
    public scan(action: Function): void;
    /**
     * Returns a copy of the queue's items without affecting its internal state.
     *
     * @public
     * @returns {Array<*>} A copy of the queue's items.
     */
    public toArray(): Array<any>;
    /**
     * Returns the queue's internal array for use by derived classes.
     *
     * @protected
     * @returns {Array<*>} The internal array.
     */
    protected _getArray(): Array<any>;
    /**
     * Returns a string representation.
     *
     * @public
     * @returns {string}
     */
    public toString(): string;
    #private;
}