import { Awaitable } from './types';
/**
 * The promise that can be resolved externally.
 *
 * @template T The value that the promise is fulfilled with.
 */
export declare class Deferred<T> extends Promise<T> {
    static get [Symbol.species](): PromiseConstructor;
    /**
     * Fulfills the promise with the specified value. If the promise has already been resolved, either to a value,
     * a rejection, or another promise, this method does nothing.
     *
     * @param value If this value is not a promise, including `undefined`, it becomes the fulfillment value of the
     * associated promise. If this value is a promise, then the associated promise will be resolved to the passed promise,
     * and follow the state as the provided promise (including any future transitions).
     */
    resolve: (value: Awaitable<T>) => void;
    /**
     * Rejects the promise with the specified reason. If the promise has already been resolved, either to a value,
     * a rejection, or another promise, this method does nothing.
     *
     * @param reason The rejection reason for the associated promise. Although the reason can be undefined, it is
     * generally an {@link Error} object, like in exception handling.
     *
     * **Note:** This argument should not be a promise. Specifying a rejected promise would make the rejection reason
     * equal to the rejected promise itself, and not its rejection reason.
     */
    reject: (reason?: any) => void;
    /**
     * Creates a new instance of {@link Deferred}.
     *
     * @template T The value that the promise is fulfilled with.
     */
    constructor();
}