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