declare function isString(value: unknown): boolean;
declare function isUndefined(value: unknown): boolean;
declare function isNotUndefined<T>(value: unknown): value is T;
declare function isTrue(value: unknown): boolean;
declare function isNotFalse(value: unknown): boolean;
declare function isFunction(value: unknown): boolean;
declare function isPlainObject<T>(value: unknown): value is T;
export { isString, isUndefined, isPlainObject, isTrue, isFunction, isNotUndefined, isNotFalse };
declare const _default: {
    isString: typeof isString;
    isUndefined: typeof isUndefined;
    isPlainObject: typeof isPlainObject;
    isTrue: typeof isTrue;
    isFunction: typeof isFunction;
    isNotUndefined: typeof isNotUndefined;
    isNotFalse: typeof isNotFalse;
};
export default _default;