This needs to be fixed

[Manu]

On Mon, 26 Aug 2024 at 18:45, Timon Gehr via Digitalmars-d <
digitalmars-d at puremagic.com> wrote:

> On 8/26/24 07:21, Walter Bright wrote:
> > On 8/24/2024 9:36 AM, Manu wrote:
> >> alias x = s.tupleof; // this works
> >> alias y = s.tupleof[0]; // this is a compile error?!
> >
> >
> > Can you please repost with the missing declarations from your example?
> > Thanks!
>
> This suffices to reproduce:
>
> ```d
> struct S{ int x; }
> S s;
> alias x = s.tupleof; // this works
> alias y = s.tupleof[0]; // this is a compile error?!
> ```
>
> The underlying issue is that `.tupleof` has some magic that is not
> accessible to aliases.
>
> Consider:
>
> ```d
> struct S{ int x; }
> void main(){
>      S s;
>      alias x = s.tupleof;
>      x[0] = 2; // ok
>      alias y = s.x;
>      y = 2; // error
> }
> ```
>
> So `x[0]` is an alias to the field of an instance.
>
> I think all of these examples should just work.
>
> When template parameters get involved however, local instantiation can
> get a bit tricky. So making it work without breakage probably also comes
> down to the issue that local instantiation works with only one context,
> which had a fix in DMD but was never ported to GDC and LDC, and was then
> reverted via deprecation in DMD as well. This is one of the most
> annoying and long-standing issues in D.
>

I endorse every word of this post.
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