export declare function isNil(val: unknown): val is null | undefined;
export declare function is(val: unknown, type: string): boolean;
export declare function isUnDef(v: any): v is undefined | null;
export declare function isDef<T>(v: T): v is NonNullable<T>;
export declare function isObject(val: any): val is Record<any, any>;
export declare function isNotEmpty(val: any): boolean;
/**
 * 是否是空
 * value is (undefined | null | '' | {} | [])
 * @returns { value is (undefined | null | '' | {} | [])}
 * @example
    isEmpty('')  // => true
    isEmpty() // => true
    isEmpty(null) // => true
    isEmpty({}) // => true
    isEmpty([]) // => true
    isEmpty(Date) // => false
    isEmpty(false) // => false
    isEmpty(true) // => false
    isEmpty(()=>{}) // => false
    isEmpty(1) // => false
    isEmpty(0) // => false
 */
export declare function isEmpty<T = unknown>(val: T): val is T;
export declare function isDate(val: unknown): val is Date;
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;
export declare function isNumber(val: unknown): val is number;
export declare function isPromise<T = any>(val: unknown): val is Promise<T>;
export declare function isString(val: unknown): val is string;
export declare function isFunction(val: unknown): val is Function;
export declare function isBoolean(val: unknown): val is boolean;
export declare function isRegExp(val: unknown): val is RegExp;
export declare function isArray(val: any): val is Array<any>;
export declare function isUrl(path: string): boolean;
export declare function isHttpUrl(path: string): boolean;