export declare class QueueNode<T> {
    value: T;
    next: QueueNode<T> | null;
    constructor(value: T);
}
export declare class Queue<T> {
    head: QueueNode<T> | null;
    tail: QueueNode<T> | null;
    size: number;
    constructor();
    enqueue(value: T): void;
    dequeue(): T | undefined;
    peek(): T | undefined;
    isEmpty(): boolean;
    [Symbol.iterator](): Iterator<T>;
}