import { Source } from "./_core";
import { In, Out } from "./_interfaces";
import { EventStream } from "./EventStream";
import { Observable } from "./Observable";
import { Property } from "./Property";
export declare function makeObservable<ObsValueType, NewValueType, ObsType = Observable<ObsValueType>>(parent: In<ObsType, ObsValueType>, source: Source<NewValueType>): Out<ObsType, NewValueType>;
export declare function makeEventStream<T>(source: Source<T>): EventStream<T>;
export declare function makeProperty<T>(source: Source<T>): Property<T>;
/**
 * Test whether the given value is Francis observable or not
 * @param x - Value to be tested
 * @returns `true` if value extends observable, otherwise `false`
 * @public
 */
export declare function isObservable<T>(x: any): x is Observable<T>;