/**
 * A CompletablePromise is a Promise whose fulfillment or rejection
 * can be triggered externally.
 *
 * @param T - the type of the object the promise can be fulfilled with.
 */
export declare class CompletablePromise<T> implements Promise<T>, PromiseLike<T> {
    /**
     * Create a new CompletablePromise that is already in the fulfilled state.
     *
     * @param value - the value to fulfill the promise with.
     */
    static resolved<U>(value: U): CompletablePromise<U>;
    [Symbol.toStringTag]: string;
    /** Backing promise object. */
    private promise;
    /** The current state of the backing promise object. */
    private stateField;
    /**
     * Construct a new CompletablePromise.
     */
    constructor();
    /**
     * Get the current state of the CompletablePromise.
     *
     * @returns 'pending' | 'resolved' | 'rejected'.
     */
    get state(): "pending" | "resolved" | "rejected";
    /**
     * Fulfill the completable promise with some value.
     *
     * @param value - The value to fulfill the promise with.
     */
    fulfill: (value: T | PromiseLike<T>) => void;
    /**
     * Reject the completable promise with an error.
     *
     * @param reason - The reason to reject the completable promise.
     */
    reject: (reason?: any) => void;
    /**
     * Attaches a single callback for both the resolution and rejection
     * of the promise.
     */
    finally(onfinally?: (() => void) | null | undefined): Promise<T>;
    /**
     * Attaches callbacks for the resolution and/or rejection of the Promise.
     */
    then<TResult1 = T, TResult2 = never>(onfulfilled?: ((value: T) => TResult1 | PromiseLike<TResult1>) | null | undefined, onrejected?: ((reason: any) => TResult2 | PromiseLike<TResult2>) | null | undefined): Promise<TResult1 | TResult2>;
    /**
     * Attaches callbacks for just the rejection of the Promise.
     */
    catch<TResult = never>(onrejected?: ((reason: any) => TResult | PromiseLike<TResult>) | null | undefined): Promise<T | TResult>;
    wait(): Promise<T>;
}