/** 是否为某个对象 */
export declare const is: (x: any, y: any) => boolean;
/**
 * Checks if `value` is `null` or `undefined`.
 *
 * @static
 * @memberOf _
 * @since 4.0.0
 * @category Lang
 * @param {*} value The value to check.
 * @returns {boolean} Returns `true` if `value` is nullish, else `false`.
 * @example
 *
 * _.isNil(null);
 * // => true
 *
 * _.isNil(void 0);
 * // => true
 *
 * _.isNil(NaN);
 * // => false
 */
export declare function isNil(value: any): boolean;
export declare function isPromise<T = any>(value: any): value is PromiseLike<T>;
export declare function isObject(val: any): boolean;
export declare function isObjectObject(o: any): boolean;
export declare function isPlainObject(o: any): boolean;
export declare function isRegExp(v: any): boolean;
/**
 * Check is Array and contains some elements
 * @param arrayLike
 */
export declare function isValidArray(arrayLike: ArrayLike<any>): boolean;
/**
 * Check if val is a valid array index.
 */
export declare function isValidArrayIndex(val: any): boolean;
/** 如果数组有有效值且对象有值，则判断为有效 */
export declare function isValid(obj: any): boolean;
/**
 * Description 获取对象类型
 * @param obj
 */
export declare function type(obj: any): string;
export declare function isFunction(maybaFunction: any): boolean;
export declare const isFunctionAlias: typeof isFunction;
/**
 * Description 判断传入的对象是否为字符串
 * @param maybeStr
 * @return {boolean}
 */
export declare function isString(maybeStr: any): boolean;
export declare const isStringAlias: typeof isString;
export declare function isUndef(v: any): boolean;
export declare function isDef(v: any): boolean;
export declare function isTrue(v: any): boolean;
export declare function isFalse(v: any): boolean;
/**
 * Check if value is primitive
 */
export declare function isPrimitive(value: any): boolean;