DIP66 - Multiple alias this

[mw]

On Monday, 28 September 2020 at 18:13:15 UTC, H. S. Teoh wrote:
> On Mon, Sep 28, 2020 at 05:59:19PM +0000, mw via Digitalmars-d 
> wrote:
>
> As somebody already said, that's all well and good for Eiffel. 
> It's not so clear how to integrate this nicely in D.

D has `alias` already, which can be used as Eiffel's `rename`, 
and by introducing the other same keywords (mechanism), we can 
adopt the Eiffel multiple inheritance.

D and Eiffel are close: D picked design-by-contract from Eiffel, 
but throw away multiple inheritance,

... and instead introduced sub-typing, mixin,

which Walter said:

https://forum.dlang.org/post/rb4seo$bfm$1@digitalmars.com

"""
The trouble was, it was inserted without realizing it was 
multiple inheritance, meaning its behaviors are ad-hoc and don't 
make a whole lot of sense when examined carefully.
"""

If we really want to fix it, can do it in D3.