import { Observable } from './Observable';
export interface UnaryFunction<T, R> {
    (source: T): R;
}
export interface OperatorFunction<T, R> extends UnaryFunction<Observable<T>, Observable<R>> {
}
export declare type FactoryOrValue<T> = T | (() => T);
export interface MonoTypeOperatorFunction<T> extends OperatorFunction<T, T> {
}