/**
 * Recursively makes all properties of T optional.
 * Arrays use element-level DeepPartial rather than making the array itself optional,
 * which allows sparse array diffs (e.g. only index 2 changed).
 */
export type DeepPartial<Value> = Value extends object ? Value extends Array<infer ArrayValue> ? Array<DeepPartial<ArrayValue>> : {
    [Property in keyof Value]?: DeepPartial<Value[Property]>;
} : Value;
/**
 * Returns true only for plain objects — intentionally excludes Array, Date, File, Map,
 * and Set so they are treated as atomic leaf values rather than being traversed.
 */
export declare const isObject: (value: unknown) => value is Record<string, any>;
/**
 * Deep-clones a value while preserving special types:
 * - Date → new Date instance with the same timestamp
 * - File → same reference (Files are immutable browser objects and cannot be meaningfully cloned)
 * - Map / Set / other class instances → same reference (treated as atomic by isObject)
 * Plain objects and arrays are recursively cloned.
 */
export declare const cloneDeep: <Value>(value: Value) => Value;