import { Cell } from './reactive';

export interface KeyedSelector<K> {
    (key: K): boolean;
    /** Number of materialized per-key cells (introspection / tests). */
    readonly size: number;
    /** Unsubscribe from the source and drop all per-key cells. Idempotent. */
    destroy(): void;
}
export declare function keyedSelector<K>(source: Cell<K> | (() => K), owner?: object, debugName?: string): KeyedSelector<K>;