Implementing interfaces using alias this

[Balagopal Komarath via Digitalmars-d-learn]

On Wednesday, 14 June 2017 at 09:41:49 UTC, ketmar wrote:
> Balagopal Komarath wrote:
>
>> Why doesn't this work? The Test!Duck type has a void quack() 
>> method but the compiler says it is not implemented.
>
> 'cause `alias this` is *not* a tool that can be used to emulate 
> inheritance. no, `quack` is NOT impemented. `alias this` won't 
> automagically paste the code.

Thanks for the reply. Is there any reason for disallowing this? 
AFAIK, the alias this guarantees that the interface provided by 
Test!T is a superset of the interface provided by T. And, when T 
= Duck, T provides everything required by IDuck. Couldn't the 
compiler check while instantiating that Test!Duck provides all 
methods required by IDuck?