"alias that this" or "alias this : that"

[Mike]

On Friday, 7 February 2014 at 22:09:21 UTC, Jesse Phillips wrote:
>
> I'd like for 'alias that this' to go away.
>
> I'm fine with 'alias this = that'
>
> If we must 'alias this : that' or "this implicitly casts to 
> that" is also reasonable to me.
>
> Yes 'alias that this' can stay for backwards compatibility.
>
> No 'alias this : that' has not been implemented (that I'm aware 
> of).

It appears it has been implemented, but not acted upon:
https://github.com/D-Programming-Language/dmd/pull/1341