import { Observable } from '../Observable'; import { MonoTypeOperatorFunction } from '../types'; /** @deprecated In future versions, empty notifiers will no longer re-emit the source value on the output observable. */ export declare function delayWhen<T>(delayDurationSelector: (value: T, index: number) => Observable<never>, subscriptionDelay?: Observable<any>): MonoTypeOperatorFunction<T>; export declare function delayWhen<T>(delayDurationSelector: (value: T, index: number) => Observable<any>, subscriptionDelay?: Observable<any>): MonoTypeOperatorFunction<T>;