declare global {
    interface AsyncIteratorObject<T, TReturn = unknown, TNext = unknown> extends AsyncIterator<T, TReturn, TNext> {
        [Symbol.asyncIterator](): AsyncIteratorObject<T, TReturn, TNext>;
    }
    interface ReadableStreamAsyncIterator<T> extends AsyncIteratorObject<T, undefined, unknown> {
        [Symbol.asyncIterator](): ReadableStreamAsyncIterator<T>;
    }
}
export interface ReadableStreamIteratorOptions {
    preventCancel?: boolean;
}
/**
 * Get an async iterable iterator from a readable stream.
 * @param readableStream
 * @param readableStreamIteratorOptions
 * @returns
 */
export declare function asyncIterator<R>(readableStream: ReadableStream<R>, { preventCancel }?: ReadableStreamIteratorOptions): ReadableStreamAsyncIterator<R>;