/**
 * A Map that holds at most `max` entries and drops the least recently used one
 * past that. Reading an entry counts as using it. `onEvict` is handed what is
 * dropped, for a cache whose values hold GPU memory.
 */
export declare class LruMap<K, V> extends Map<K, V> {
    private readonly max;
    private readonly onEvict?;
    constructor(max: number, onEvict?: ((value: V, key: K) => void) | undefined);
    get(key: K): V | undefined;
    set(key: K, value: V): this;
}
/** Keeps `value` as one variant of `key`, such as one flatness a path is traced at. */
export declare function setVariant<V>(cache: LruMap<string, Map<string, V>>, key: string, variant: string, value: V): void;