Why can't structs be derived from?

[Steven Schveighoffer]

On Tue, 15 Mar 2011 15:28:09 -0400, Jens <jne at somewhere.org> wrote:

> Steven Schveighoffer wrote:
>> On Tue, 15 Mar 2011 14:54:13 -0400, Jens <jne at somewhere.org> wrote:
>>
>>> I didn't ask how to do composition in D. I asked why composition
>>> cannot be done via derivation, i.e., the reasoning behind the
>>> language design choice. A design faux paus IMO.
>>
>> Because composition by inheritance can be *completely* implemented
>> using alias this -- a feature that also provides other niceties.  Why
>> provide another mechanism to do the exact same thing, just because
>> you are used to it?
>
> 1. I'm not convinced the other functionality is necessary.
> 2. I eschew ugly syntax.

Beauty is subjective, so I guess I can say at this point, go write your  
own language that is beautiful in your mind.  Good luck.

>
>>
>> Note that "inheritance" is actually done exactly this way in C++, by
>> putting the derived type at the front of the "derived" type, and
>> aliasing all the methods/fields into the derived namespace.
>>
>> Show me what composition by derivation provides that alias this does
>> not.
>
> Nice syntax.

So in other words, you want an aqua-blue bikeshed, when D's is just blue.

This will be my last reply to this thread...

-Steve