Preview features status?

[Tejas]

On Tuesday, 13 July 2021 at 18:20:36 UTC, evilrat wrote:
> On Tuesday, 13 July 2021 at 15:51:26 UTC, Tejas wrote:
>>
>> Shouldn't this be a bug? Isn't this still ```const - 
>> non-const```?
>> Do you think this is worth filing?
>
> Definitely a bug from usability point. But...
>
> Well, seems like it is just yet another half baked feature 
> according to this GH issue, also it seems like it was supposed 
> to be superseded by relevant "in" qualifier for extern(C++) but 
> that DIP seems to be abandoned as well.
>
> https://github.com/dlang/dmd/pull/12064
>
>> Also, where did you find out how to represent rvalue 
>> references as parameters? I couldn't find any info on that. 
>> Just learned that these are available under a preview switch.
>
> Can't find it anywhere in release notes, it was just silently 
> showed up around Apr 2019.

Does your code "just work" if you use  ```preview=in``` instead? 
Could be a good reason to just get rid of the 
```rvaluerefparam``` then.