import { Source, Subscriber, Subscription } from "../_core";
import { EventStream } from "../EventStream";
import { Observable } from "../Observable";
import { Identity } from "./_base";
export declare function toEventStream<ValueType>(observable: Observable<ValueType>): EventStream<ValueType>;
export declare class ToEventStream<T> extends Identity<T> {
    constructor(source: Source<T>);
    subscribe(subscriber: Subscriber<T>, order: number): Subscription;
    activate(initialNeeded: boolean): void;
}