UDAs - Restrict to User Defined Types?

[simendsjo]

On Thursday, 8 November 2012 at 09:05:31 UTC, Jacob Carlborg 
wrote:
> I think we should only allow user defined types marked with 
> @attribute, i.e.
>
> @attribute struct foo {}
> @attribute class foo {}
> @attribute interface foo {}
> @attribute enum foo {}
>
> And so on.

Or
struct @foo {}
interface @foo {}
enum @foo {0
etc