Which language constructs could be done as a library if we accept some breaking changes?

[Ola Fosheim Grøstad]

On Sunday, 28 November 2021 at 21:01:53 UTC, Elronnd wrote:
> On Sunday, 28 November 2021 at 20:47:28 UTC, Ola Fosheim 
> Grøstad wrote:
>> Which features that are currently in the language could with 
>> some adjustments be done as a library feature?
>>
>> Class?
>
> Classes should be a language feature in any case, for 
> performance reasons

A good compiler will detect standard library features and use a 
fast-path/optimized-path for those. So there should be no 
performance impact.