export declare class DeferredPromise<T> {
    promise: Promise<T>;
    resolve: (value: T) => void;
    reject: (error: Error) => void;
    private settled;
    constructor();
    get isSettled(): boolean;
}
export declare function createDeferred<T>(): DeferredPromise<T>;
export interface Deferred<T> {
    promise: Promise<T>;
    resolve: (value: T) => void;
    reject: (reason?: any) => void;
}
export declare function defer<T>(): Deferred<T>;