/**
 * Checks if `test` is `undefined`.
 *
 * @param {*} test The value to check.
 * @returns {boolean} Returns `true` if `value` is `undefined`, else `false`.
 * @example
 *
 *      isUndefined(void 0);  //=> true
 *      isUndefined(null);    //=> false
 */
export declare const isUndefined: (test: any) => test is undefined;
export default isUndefined;