Multiple alias this, what's the hold up?

[Timon Gehr]

On 17.06.19 00:14, Walter Bright wrote:
> On 6/16/2019 7:39 AM, Timon Gehr wrote:
>> On 16.06.19 08:08, Walter Bright wrote:
>>> Multiple alias this is multiple inheritance.
>>
>> No. It's multiple imports.
> 
> D already has multiple imports with template mixins. If multiple imports 
> is what people want, it's already there.
> ...

No. Mixins and imports are not the same thing. E.g., this code is fine:

import std.stdio;

void main(){
     writeln("hello world!");
}

This code is horrible (it does not even compile):

mixin(import("std/stdio.d"));

void main(){
     writeln("hello world!");
}

(Whether the automated copy-pasting of code happens before or after 
parsing doesn't really matter.)