alias can't find symbol or can't use symbol

[Carl Sturtivant via Digitalmars-d-learn]

On Wednesday, 3 May 2017 at 09:04:07 UTC, Jonathan M Davis wrote:
> I believe that the core problem is that an alias declaration 
> just aliases a symbol - i.e. it just creates a new name for the 
> symbol. And as far as I can tell,
>
> alias n2 = x2.n;
>
> is actually equivalent to
>
> alias n2 = member.n;
>
> You get exactly the same error message if that change is made. 
> It's a bit like how you can call a static function with an 
> object rather than the struct/class(e.g. s.foo() instead of 
> S.foo()). Similarly, if you turn n into a member function, then 
> you get an error like
>
> q.d(20): Error: this for n needs to be type member not type 
> outer
>
> It's just aliasing the function, not creating a delegate or 
> doing a syntactic conversion. If it _were_ doing a syntactic 
> conversion and just making it so that everywhere you see n2, it 
> got changed to x.n, then I could see code like
>
> outer o;
> o.n2 = 5;
>
> working. But that's not how alias declarations work. They just 
> create a new name for the symbol in the scope that they're 
> declared. So, the symbol isn't tied to a particular instance, 
> and you get the problem that you're having.

The following works with
     outer2 o;
     o.n2 = 5;
so it's not static, i.e. n2 is tied to the instance here.

struct outer2
{
     int n;
     alias n2 = n;
}

So it seems reasonable to have better semantics for an embedded 
struct with alias_this.