/* 0.28.0 */
export type CachedValue<T> = {
    value: T | null;
    generation: number | undefined;
};
/** The cache v will get updated if necessary */
export declare function cachedValue<T>(v: CachedValue<T>, generation: number | undefined, fn: () => T): T;
export declare function cachedValueAsync<T>(v: CachedValue<T>, generation: number | undefined, fn: () => Promise<T>): Promise<T>;