/**
 * @packageDocumentation
 * @module Utility
 */
import { MonoTypeOperatorFunction } from 'rxjs';
/**
 * Returns the source Observable, emitting it through the passed WritableStream and handling the internal
 * subscription state and error handling. If passed an
 * {@link https://developer.mozilla.org/en-US/docs/Web/API/AbortSignal|AbortSignal} the WritableStream can be ended
 * early without ending the entire subscription
 *
 * @category Streams
 *
 * @see {@link https://stackblitz.com/edit/rxjs-writable-stream|Writable Stream Demo}
 *
 * @param stream The Writer object to emit the data to
 * @param signal Optional signal used to end the writer without ending the rest of the stream
 *
 * @example Write an array of Observable values to a WritableStream
 * ```ts
 * let result = ''
 * const stream = new WritableStream({
 *   write: (chunk) => result += chunk,
 *   close: () => console.log(result)
 * });
 *
 * const input = ['Hello', ' ', 'RxJS', ' ', 'Ninja'];
 * from(input).pipe(toWritableStream(stream)).subscribe();
 * ```
 * Output: `Hello RxJS Ninja`
 *
 * @returns Observable that emits the source observable after performing a write to the WritableStream
 */
export declare function toWritableStream<T extends unknown>(stream: WritableStream<T> | WritableStreamDefaultWriter<T>, signal?: AbortSignal): MonoTypeOperatorFunction<T>;