"Multiple alias this" status?

[Picaud Vincent via Digitalmars-d]

Hi All,

I just started to learn a little bit of D.

I read this thread
https://github.com/dlang/dmd/pull/3998

about "Multiple alias this".

I think this feature is very handy, but dmd and gcd compilers 
complain that "there must be only one" alias this.

It is not clear to me if this feature is not available yet or if 
there was a change in the language specifications (Andrei 
Alexandrescu book mentions "§6.13 Multiple subtyping") ?

Does anyone has more information concerning that?

Thanks in advance,
Vincent