import { OperatorFunction, SubscribableOrPromise } from '../types';
/**
 * Buffers the source Observable values starting from an emission from
 * `openings` and ending when the output of `closingSelector` emits.
 *
 * <span class="informal">Collects values from the past as an array. Starts
 * collecting only when `opening` emits, and calls the `closingSelector`
 * function to get an Observable that tells when to close the buffer.</span>
 *
 * ![](bufferToggle.png)
 *
 * Buffers values from the source by opening the buffer via signals from an
 * Observable provided to `openings`, and closing and sending the buffers when
 * a Subscribable or Promise returned by the `closingSelector` function emits.
 *
 * ## Example
 *
 * Every other second, emit the click events from the next 500ms
 *
 * ```javascript
 * const clicks = fromEvent(document, 'click');
 * const openings = interval(1000);
 * const buffered = clicks.pipe(bufferToggle(openings, i =>
 *   i % 2 ? interval(500) : empty()
 * ));
 * buffered.subscribe(x => console.log(x));
 * ```
 *
 * @see {@link buffer}
 * @see {@link bufferCount}
 * @see {@link bufferTime}
 * @see {@link bufferWhen}
 * @see {@link windowToggle}
 *
 * @param {SubscribableOrPromise<O>} openings A Subscribable or Promise of notifications to start new
 * buffers.
 * @param {function(value: O): SubscribableOrPromise} closingSelector A function that takes
 * the value emitted by the `openings` observable and returns a Subscribable or Promise,
 * which, when it emits, signals that the associated buffer should be emitted
 * and cleared.
 * @return {Observable<T[]>} An observable of arrays of buffered values.
 * @method bufferToggle
 * @owner Observable
 */
export declare function bufferToggle<T, O>(openings: SubscribableOrPromise<O>, closingSelector: (value: O) => SubscribableOrPromise<any>): OperatorFunction<T, T[]>;