/**
 * Assign properties, constructors, etc. to an object
 *
 * @param target - The target object that gets `sources` assigned to it
 * @param sources - The sources to be assigned to the target object
 * @return An object representing the union of the target and sources objects
 */
export declare const assign: (target: object, ...sources: object[]) => object;
/**
 * Deep clone an object.
 *
 * @param source - Object to be cloned.
 * @return Cloned `source` object.
 */
export declare const deepClone: (source: object) => object;
/**
 * Extend an object with another object.
 *
 * @param target - Target object or `undefined` if a new object should
 *   be created.
 * @param source - Object to be cloned.
 * @return Cloned `source` object
 */
export declare const extend: (target: object | undefined, source: object) => object;
/**
 * Update the target object by the source object. Besides extending that target
 * object, properties that are not present in the source object.
 *
 * @param target - Target object
 *   be created.
 * @param source - Object to be cloned.
 * @return Cloned `source` object
 */
export declare const update: (target: object, source: object) => object;
/**
 * Invert an object by swapping its keys and values.
 *
 * @example
 * ```js
 * invert({ a: 'cool', b: 'sweet' });
 * // => { cool: 'a', sweet: 'b' }
 * ```
 *
 * @param obj - The object to be inverted.
 * @return Inverted object
 */
export declare const invert: (obj: Record<string, string | number>) => Record<string, string>;