import { Observable } from '../Observable';
/**
 * Emits the values emitted by the source Observable until a `notifier`
 * Observable emits a value.
 *
 * <span class="informal">Lets values pass until a second Observable,
 * `notifier`, emits something. Then, it completes.</span>
 *
 * <img src="./img/takeUntil.png" width="100%">
 *
 * `takeUntil` subscribes and begins mirroring the source Observable. It also
 * monitors a second Observable, `notifier` that you provide. If the `notifier`
 * emits a value or a complete notification, the output Observable stops
 * mirroring the source Observable and completes.
 *
 * @example <caption>Tick every second until the first click happens</caption>
 * var interval = Rx.Observable.interval(1000);
 * var clicks = Rx.Observable.fromEvent(document, 'click');
 * var result = interval.takeUntil(clicks);
 * result.subscribe(x => console.log(x));
 *
 * @see {@link take}
 * @see {@link takeLast}
 * @see {@link takeWhile}
 * @see {@link skip}
 *
 * @param {Observable} notifier The Observable whose first emitted value will
 * cause the output Observable of `takeUntil` to stop emitting values from the
 * source Observable.
 * @return {Observable<T>} An Observable that emits the values from the source
 * Observable until such time as `notifier` emits its first value.
 * @method takeUntil
 * @owner Observable
 */
export declare function takeUntil<T>(this: Observable<T>, notifier: Observable<any>): Observable<T>;
