import { In, Out } from "../_interfaces";
import { EventStream } from "../EventStream";
import { Property } from "../Property";
/**
 * For `EventStream`, this operator adds an extra event with the given value
 * to the beginning of the stream.
 *
 * For `Property`, this operator ensures that the property has an initial value.
 * If the property already has an initial value then this operator is a no-op.
 *
 * @param value Value to be added to the stream / property's initial value
 * @param observable Source observable
 *
 * @example
 *
 * F.pipe(F.once(1),
 *  F.startWith(2),
 *  F.startWith(3),
 *  F.log("EventStream"))
 * // logs: 3, 2, 1, <end>
 *
 * F.pipe(F.constant(1),
 *  F.startWith(2),
 *  F.startWith(3),
 *  F.log("Property"))
 * // logs: 1, <end>
 *
 * @public
 */
export declare const startWith: CurriedStartWith;
interface CurriedStartWith {
    <ObsType, ValueType>(value: ValueType, observable: In<ObsType, ValueType>): Out<ObsType, ValueType>;
    <ValueType>(value: ValueType): <ObsType>(observable: In<ObsType, ValueType>) => Out<ObsType, ValueType>;
}
export declare function _startWithE<T>(value: T, stream: EventStream<T>): EventStream<T>;
export declare function _startWithP<T>(value: T, property: Property<T>): Property<T>;
export {};