dip1000 and preview in combine to cause extra safety errors

[Mathias LANG]

On Thursday, 9 June 2022 at 01:18:30 UTC, Steven Schveighoffer 
wrote:
>
> 2. The programmer is *not* expecting this. They did not write 
> `scope`, they wrote `in`, which according to the spec is 
> "equivalent to const" (see 
> https://dlang.org/spec/function.html#in-params). I'm convinced 
> that we *absolutely cannot* turn on preview in by default until 
> this is addressed. I can't even recommend using the preview 
> switch, as this is too dangerous for memory safety.

According to the spec, `in` means `const scope` when you are 
using `-preview=in`.