BFE.devでのAI解答例 - TypeScript タイプパズル
28. implement IsEmptyType<T>

type IsEmptyType<T> = keyof T extends never ? true : false;

Explanation:

• keyof T returns the union of all possible keys of T.
• never is an empty type, so if keyof T evaluates to never, it means T has no possible keys, thus it is an empty type.
• We use a conditional type to check if keyof T extends never. If it does, it means T is an empty type, and we return true. Otherwise, we return false.