The state of string interpolation

[Martin Tschierschke]

On Thursday, 6 December 2018 at 00:32:48 UTC, Adam D. Ruppe wrote:
> On Thursday, 6 December 2018 at 00:20:53 UTC, H. S. Teoh wrote:
>> Why can't this be added to to code.dlang.org as a library / 
>> dub package / whatever?
>
> Library things cannot access the local scope of the string 
> unless you mixin.
>
> So
>
> mixin(interp!"foo #{a}");
>
> is doable as a library (and I know Nick Sabalusky's scriptlike 
> has it, probably among others), but
>
> string b = "foo #{a}";
>
> is only doable as a language feature.

I am referring to this post, because it is the first mentioning 
the mixin way in this thread:

           Why is mixin() not allowed in UFCS?


it may become way nicer, and with an alias i=interp; we would have

=>

writeln(i!"foo #{a}".mixin) // which is not to far away from 
writeln(i"foo #{a}")
or:
i!"foo #{a}".mixin.writeln;