/**
 * An simple, efficient queue implementation with amortized O(1) operations,
 * using a circular buffer.
 *
 * Dynamically resizes to manage memory usage.
 *
 * @template T The type of elements held in the queue.
 */
export declare class Queue<T> implements Iterable<T> {
    #private;
    /**
     * Creates a new Queue instance.
     *
     */
    constructor();
    /**
     * Adds an item to the back of the queue.
     *
     * @param {T} item The item to add to the queue.
     * @returns {number} The new size of the queue.
     */
    enqueue(item: T): number;
    /**
     * Removes and returns the item at the front of the queue.
     *
     * @returns {T | undefined} The item at the front of the queue, or undefined if the queue is empty.
     */
    dequeue(): T | undefined;
    /**
     * Returns the item at the front of the queue without removing it.
     *
     * @returns {T | undefined} The item at the front of the queue, or undefined if the queue is empty.
     */
    peek(): T | undefined;
    /**
     * Returns the element at the specified index in the queue without removing it.
     *
     * @param {number} index - The index of the element to retrieve (0-based).
     * @returns {T | undefined} The element at the specified index, or undefined if the index is out of bounds.
     */
    get(index: number): T | undefined;
    /**
     * Returns the number of items in the queue.
     *
     * @returns {number} The number of items in the queue.
     */
    get size(): number;
    /**
     * Returns the internal size of the queue.
     *
     * @returns {number} The internal size of the queue.
     */
    get internalSize(): number;
    /**
     * Removes all items from the queue.
     */
    clear(): void;
    /**
     * Creates an iterator for the elements in the queue.
     *
     * @generator
     * @yields {T} The next element in the queue.
     * @returns {Generator<T>} A generator that yields elements of type T.
     */
    [Symbol.iterator](): Generator<T>;
    /**
     * Creates an iterator for the elements in the queue.
     *
     * @generator
     * @yields {[T, number]} A tuple containing the element and its index in the queue.
     * @returns {Generator<[T, number]>} A generator that yields tuples of elements of type T and their indices.
     */
    entries(): Generator<[T, number]>;
    /**
     * Returns a string representation of the queue.
     *
     * @returns {string} A string representation of the queue in the format:
     *                   "Queue(size) { item1, item2, ... }"
     */
    toString(): string;
    /**
     * Executes a provided function once for each queue element.
     *
     * @param {function} callbackFn - Function to execute for each element, taking three arguments:
     * @param {T} callbackFn.value - The current element being processed in the queue.
     * @param {number} callbackFn.index - The index of the current element being processed in the queue.
     * @param {Queue<T>} callbackFn.queue - The queue object forEach() was called upon.
     *
     * @throws {TypeError} If callbackFn is not a function.
     */
    forEach(callbackFn: (value: T, index: number, queue: Queue<T>) => void): void;
}