export declare function sortByKey<V, S>(collection: Iterable<V>, sortKey: (v: V) => S, comparator: (a: S, b: S) => number): Iterable<V>;
export declare function sortByKey<V>(collection: Iterable<V>, sortKey: (v: V) => number): Iterable<V>;
export declare const gc: <K, V, S>(entries: IterableIterator<[K, V]>, sortKey: (v: V) => S, sortKeyComparer: (a: S, b: S) => number, weigher: (v: V) => Promise<number>, limit: number, deleter: (k: K) => void) => Promise<number>;
export declare class GcMap<K, V> extends Map<K, V> {
    gc<S>(limit: number, sortKey: (v: V) => S, weigher: (v: V) => Promise<number>, sortKeyComparer: (a: S, b: S) => number): Promise<number>;
    weight(weigher: (v: V) => Promise<number>): Promise<number>;
}