import "../_dnt.polyfills.js";
export interface MapLike<K, V> {
    set(key: K, value: V): void;
    get(key: K): undefined | V;
}
export declare function getOrInit<K, V>(container: MapLike<K, V>, key: K, init: () => V): V;
export declare class WeakRefMap<K, V extends object> {
    map: Map<K, WeakRef<V>>;
    finReg: FinalizationRegistry<K>;
    get(key: K): V | undefined;
    set(key: K, value: V): void;
    delete(key: K): boolean;
}