String Interpolation

[Adam D Ruppe]

On Saturday, 21 October 2023 at 15:59:06 UTC, duckchess wrote:
> can we just lower ```___""``` into ```mixin(___!"")```, where 
> ```___``` can be any template name. this way you can implement 
> whatever interpolation method you want in a library.

https://github.com/adamdruppe/interpolation-examples/blob/master/01-basics.d

I'll add more examples to that repo as I have time, but this 
implementation allows libraries to do whatever methods they want.