import { Optional } from '.';
export default class Queue<T> {
    private items;
    constructor(initElm: T[]);
    /**
     * The function takes a variable number of arguments of type T and pushes them into the items array
     * @param {any[]} elm - T[]
     */
    push(...elm: T[]): void;
    /**
     * It returns the first element of the array
     * @returns The first item in the array.
     */
    peek(): Optional<T>;
    /**
     * It removes the first element from an array and returns that element
     * @returns The first element of the array.
     */
    shift(): Optional<T>;
    /**
     * Returns true if the queue is empty, false otherwise
     * @returns The method returns a boolean value.
     */
    empty(): boolean;
    toString(): string;
    /**
     * This function returns a copy of the items array.
     * @returns The clone of the items array.
     */
    toArray(): T[];
    /**
     * It takes the items array and converts it to a JSON string.
     * @returns The JSON string representation of the items array.
     */
    toJSONString(): string;
    [Symbol.iterator](): Iterator<T>;
}