Two years ago I proposed the feature with experimental compiler change, but it was properly rejected.
https://github.com/D-Programming-Language/dmd/pull/459

Kenji Hara


2013/7/30 JS <js.mdnq@gmail.com>
On Tuesday, 30 July 2013 at 13:03:47 UTC, monarch_dodra wrote:
On Tuesday, 30 July 2013 at 12:25:47 UTC, JS wrote:
First how does that remove having to type mixin every time?

That will *never* happen. Having the keyword *mixin* at call site is important so the caller understand what is actually happening. Without this, you are basically injecting a macro into caller code. Good luck with the re-read.

Um, so? You think my d source is going to be hacked? Someone is going to turn all my templates into string mixins and trick me?