> Using the current git version of dmd I realized that C works! Hence, as
> a workaround it can be used by creating a local alias A and subsequently
> using A.Alias in the is-expressions. But it seems odd that
>
> "alias typeof(X).A B;" does not work but
> "alias typeof(X) Y; alias Y.A B;" does.
>
> Is this considered as a bug?

I should say so: it's surprising, and limiting for the user.