-preview=in might break code

[Ola Fosheim Grøstad]

On Saturday, 3 October 2020 at 12:09:34 UTC, Mathias LANG wrote:
> On Saturday, 3 October 2020 at 05:02:36 UTC, Andrei 
> Alexandrescu wrote:
>> [...]
>>
>> Wait a SECOND! Are we really in the market of developing and 
>> deploying language features that come unglued at the slightest 
>> and subtlest misuse? We most certainly shouldn't.
>
> I agree. What I don't agree with is that this aliasing is a 
> "slight and subtle misuse". I went through the 64 projects and 
> their dependencies that are on Buildkite, and didn't see a hint 
> of this pattern emerging. Nor did it in any other code I've 
> surveyed in the almost 5 months the PR was open.

The codebases you look at are too small. If you look at the 
design rationale for Ada SPARK (which does not allow aliasing) 
you will see that aliasing is considered to be a problem that 
leads to very serious bugs in running systems.

This is well established irrespective of language.