export interface ObservableNextEvent<T> {
    value: T;
    completed: false;
    failed: false;
}
export interface ObservableErrorEvent<E> {
    error: E;
    completed: false;
    failed: true;
}
export interface ObservableCompletedEvent {
    completed: true;
    failed: false;
}
export declare type ObservableEvent<T, E = any> = ObservableNextEvent<T> | ObservableErrorEvent<E> | ObservableCompletedEvent;
export declare function next<T>(value: T): ObservableNextEvent<T>;
export declare function error<E>(e: E): ObservableErrorEvent<E>;
export declare function completed(): ObservableCompletedEvent;
export declare function isNextEvent<T>(event: ObservableEvent<T>): event is ObservableNextEvent<T>;
export declare function isErrorEvent<E>(event: ObservableEvent<unknown, E>): event is ObservableErrorEvent<E>;
export declare function isCompletedEvent(event: ObservableEvent<unknown>): event is ObservableCompletedEvent;