/**
 * @description: 判断值是否未某个类型
 */
export declare function is(val: unknown, type: string): boolean;
/**
 * @description:  是否为函数
 */
export declare function isFunction<T = Function>(val: unknown): val is T;
/**
 * @description: 是否已定义
 */
export declare const isDef: <T = unknown>(val?: T) => val is T;
export declare const isUnDef: <T = unknown>(val?: T) => val is T;
export declare function isNull(val: unknown): val is null;
export declare function isNullAndUnDef(val: unknown): val is null | undefined;
export declare function isNullOrUnDef(val: unknown): val is null | undefined;
/**
 * @description: 是否为对象
 */
export declare const isObjectX: (val: any) => val is Record<any, any>;
/**
 * @description:  是否为时间
 */
export declare function isDate(val: unknown): val is Date;
/**
 * @description:  是否为数值
 */
export declare function isNumber(val: unknown): val is number;
/**
 * @description:  是否为AsyncFunction
 */
export declare function isAsyncFunction<T = any>(val: unknown): val is Promise<T>;
/**
 * @description:  是否为promise
 */
export declare function isPromise<T = any>(val: unknown): val is Promise<T>;
/**
 * @description:  是否为字符串
 */
export declare function isString(val: unknown): val is string;
/**
 * @description:  是否为boolean类型
 */
export declare function isBoolean(val: unknown): val is boolean;
/**
 * @description:  是否为数组
 */
export declare function isArray(val: any): val is Array<any>;
/**
 * @description: 是否客户端
 */
export declare const isClient: () => boolean;
/**
 * @description: 是否为浏览器
 */
export declare const isWindow: (val: any) => val is Window;
export declare const isElement: (val: unknown) => val is Element;
export declare const isServer: boolean;
export declare function isImageDom(o: Element): boolean;
/**
 * 是否为空
 * @param source
 * @returns
 */
export declare function isEmpty(source: unknown): boolean;
/**
 * 是否是异常
 * @param val
 * @returns
 */
export declare function isError(val: unknown): boolean;
/**
 * 判断元素是否为WeakSet
 * @param source
 * @returns
 */
export declare function isWeakSet(source: unknown): boolean;
/**
 * @description 判断元素是否为WeakMap
 * @param {*} source 元素
 * @return {Boolen}
 */
export declare function isWeakMap(source: unknown): boolean;
/**
 * @description 判断元素是否为Symbol
 * @param {*} source 元素
 * @return {Boolen}
 */
export declare function isSymbol(source: unknown): boolean;
/**
 * @description 判断元素是否为Map
 * @param {*} source 元素
 * @return {Boolen}
 */
export declare function isMap(source: unknown): boolean;
/**
 * 是否有效的URL地址
 * @param url
 * @returns
 */
export declare const isValidURL: (url: string) => boolean;