export interface Subject<T> extends AsyncIterable<T> {
    /**
     * whether the subject has been disposed.
     */
    readonly isDisposed: boolean;
    /**
     * push an item into the subject to yield
     * @param {T} item the item to buffer and yield to the consumer.
     * @returns {number} the number of items stored in the internal buffer
     */
    next(item: T): number;
    /**
     * immediately rethrow an error to the consumer
     * @param err the error object to rethrow
     */
    error(err: any): void;
    /**
     * signal the the pushed sequence is complete
     */
    done(): void;
    /**
     * raised when the Subject has been disposed
     */
    on(event: "disposed", cb: () => void): any;
    /**
     * raised when the Subject has yielded an item.
     * @param {number} cb.remaining remaining items in the internal buffer
     */
    on(event: "pull", cb: (remaining: number) => void): any;
}
export default function <T>(): Subject<T>;