/**
 * 递归合并两个或多个对象
 * Copyright (c) 2024 xxm
 *
 * @template T - 目标对象类型
 * @template U - 源对象类型
 * @param {T} target - 目标对象
 * @param {U} source - 源对象
 * @returns {T & U} 返回合并后的新对象
 * @example
 *
 * ```ts
 * const obj1 = { a: 1, b: { c: 2 } };
 * const obj2 = { b: { d: 3 }, e: 4 };
 *
 * const result = deepMerge(obj1, obj2);
 * // 结果: { a: 1, b: { c: 2, d: 3 }, e: 4 }
 * ```
 */
export declare function deepMerge<T extends Record<string, any>, U extends Record<string, any>>(target: T, source: U): T & U;