/**
 * @license
 * Copyright 2017 Google LLC
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/**
 * Do a deep-copy of basic JavaScript Objects or Arrays.
 */
export declare function deepCopy<T>(value: T): T;
/**
 * Copy properties from source to target (recursively allows extension
 * of Objects and Arrays).  Scalar values in the target are over-written.
 * If target is undefined, an object of the appropriate type will be created
 * (and returned).
 *
 * We recursively copy all child properties of plain Objects in the source- so
 * that namespace- like dictionaries are merged.
 *
 * Note that the target can be a function, in which case the properties in
 * the source Object are copied onto it as static properties of the Function.
 *
 * Note: we don't merge __proto__ to prevent prototype pollution
 */
export declare function deepExtend(target: unknown, source: unknown): unknown;