Undefined

A value can conform to a boolean IFF it is undefined.

This base type isn't very helpful, but can be combined with Union types to create more complex types. See Undefinable for an example.

Usage

import { T } from "type-guarder";
 
T.Undefined().conforms(undefined); // true
T.Undefined().conforms(null); // false
T.Undefined().conforms("Hello, world!"); // false