import { AsyncDirective } from 'lit/async-directive.js';
import { DirectiveResult } from 'lit/directive.js';
interface Observable<T> {
    subscribe: (callback: (value: T) => unknown) => Subscription;
}
interface Subscription {
    unsubscribe: () => unknown;
}
declare class ObserveDirective extends AsyncDirective {
    private observable;
    private subscription;
    private callback?;
    render<T>(observable: Observable<T>, callback?: (value: T) => unknown): symbol;
    private subscribe;
    disconnected(): void;
    reconnected(): void;
}
export declare const observe: <T>(observable: Observable<T>, callback?: (value: T) => unknown) => DirectiveResult<typeof ObserveDirective>;
export {};