alias restriction??!

[Basile B.]

On Saturday, 18 July 2020 at 22:49:18 UTC, Dennis wrote:
> On Saturday, 18 July 2020 at 18:46:16 UTC, Carl Sturtivant 
> wrote:
>> Is there any way to avoid the duplication of the entries in 
>> the anonymous union, aside from using a mixin template?
>
> I think this would be fixed if 
> https://github.com/dlang/dmd/pull/11273 gets merged.

The feature still needs some work. With this PR aliases of 
members only works when they are declared in a function scope and 
not in the aggregate scope.

Example:

---
struct Inner
{
     int a;
}

struct TopLevel
{
     Inner inner;
     alias ia = inner.a;
}

void main()
{
     TopLevel tl;
     alias ia = tl.inner.a;
     ia = 42;        // OK with PR 11273
     tl.ia = 42;     // NG Error: need `this` for `a` of type `int`
}
---

I think it's not good to merge until the second case works.
Also it requires approval. For now it is specified that 
expressions cant be aliased.