Why can't structs be derived from?

[Bekenn]

On 3/17/2011 2:36 PM, Andrei Alexandrescu wrote:
>
> I'm with y'all too. Even Walter needs to stop and think for a second.
> We're considering enabling
>
> alias a = b;
>
> as an equivalent for
>
> alias b a;
>

Along similar lines (hoping this isn't too far off-topic), what's the 
current plan for typedef?  I'm aware that it's deprecated (and for good 
reason), but some of my reading suggests that there's a successor on the 
horizon.