/** @template T */
export default class FlatQueue<T> {
    /** @type T[] */
    ids: T[];
    /** @type number[] */
    values: number[];
    /** Number of items in the queue. */
    length: number;
    /** Removes all items from the queue. */
    clear(): void;
    /**
     * Adds `item` to the queue with the specified `priority`.
     *
     * `priority` must be a number. Items are sorted and returned from low to high priority. Multiple items
     * with the same priority value can be added to the queue, but there is no guaranteed order between these items.
     *
     * @param {T} item
     * @param {number} priority
     */
    push(item: T, priority: number): void;
    /**
     * Removes and returns the item from the head of this queue, which is one of
     * the items with the lowest priority. If this queue is empty, returns `undefined`.
     */
    pop(): T | undefined;
    /** Returns the item from the head of this queue without removing it. If this queue is empty, returns `undefined`. */
    peek(): T | undefined;
    /**
     * Returns the priority value of the item at the head of this queue without
     * removing it. If this queue is empty, returns `undefined`.
     */
    peekValue(): number | undefined;
    /**
     * Shrinks the internal arrays to `this.length`.
     *
     * `pop()` and `clear()` calls don't free memory automatically to avoid unnecessary resize operations.
     * This also means that items that have been added to the queue can't be garbage collected until
     * a new item is pushed in their place, or this method is called.
     */
    shrink(): void;
}