Why can't structs be derived from?

[Don]

Andrei Alexandrescu wrote:
> On 3/17/11 11:21 AM, Andrej Mitrovic wrote:
>> On 3/17/11, Nick Sabalausky<a at a.a>  wrote:
>>> I've long been convinced that "alias old new;" should really be 
>>> "alias new =
>>> old;" The current way confuses me, and I *still* have to consciously 
>>> stop
>>> and think about it every time I write an alias statement (including just
>>> now).
>>>
>>
>> I thought I was the only one. The `alias symbol this` in structs in
>> particular always stops me and I have to think about what it means,
>> even though it might be obvious.
> 
> 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;
> 
> 
> Andrei

That would be great!