DIP 1027---String Interpolation---Format Assessment

[12345swordy]

On Monday, 24 February 2020 at 19:45:49 UTC, Adam D. Ruppe wrote:
> On Monday, 24 February 2020 at 19:35:16 UTC, Walter Bright 
> wrote:
>> Having the compiler lower string interpolation to some hidden 
>> template is - AST macros. We're not doing AST macros.
>
> This is untrue.
>
>> Hidden user-defined semantics are not for D.
>
> We are NOT calling for this.
>
>
> What, exactly, do you think we're proposing?

I knew it. You needs an actual implementation here, to show 
walter what you are talking about. This reminds me of the whole 
mangle only discussion a while back. It took an actual PR for 
Walter to accept it instead of days arguing with him.

Let get to work on this.

-Alex