Interpolated strings

[Jonas Drewsen via Digitalmars-d]

On Monday, 17 April 2017 at 19:12:37 UTC, Martin Tschierschke 
wrote:
> defining a new method exho! (derived from echo + mixin...:-)
>
>   auto exho(string x)(){
>      return mixin("writeln("~interp!x~")");}
>
> You can just write:
>
>    exho!"The number ${num} doubled is ${num * 2}!"

It requires 'num' to be available to the exho function definition 
so will not
work in the general case.