25. implement UnwrapPromise<T>

TypeScript

  - accepted / - tried

Implement UnwrapPromise<T> to return the resolved type of a promise.

type A = UnwrapPromise<Promise<string>> // string
type B = UnwrapPromise<Promise<null>> // null
type C = UnwrapPromise<null> // Error

5分間以内で解いてみて