Preview features status?

[Mathias LANG]

On Wednesday, 14 July 2021 at 08:24:03 UTC, Tejas wrote:
> Last question:
>
> How do you _exactly_ specify that you're expecting a rvalue 
> reference as a parameter?
> In other words, what is the D equivalent of this C++ code:
>
> ``` func(T&& parameter) {  }```

There isn't. `in` is for const references. 
`-preview=rvaluerefparam` will allow you to get a mutable ref, 
but it simply creates a temporary at the call site (so does 
`-preview=in`). To my knowledge, we can't represent that in D 
(and we can't bind to such a definition in C++).