I just wanted to share, based on TheGag96's work porting D to devkitarm 3DS, I have successfully ported D to GBA along with D headers for the entirety of libtonc.

https://github.com/redthing1/gba_dlang
https://beanmachine.alt.icu/post/d_on_gba/

This pretty much gives you drop in, full support for D on GBA (in betterC mode of course).

On Wednesday, 9 February 2022 at 02:58:38 UTC, redthing1 wrote:

Hey, nice to see you post this here! Something you should know - I recently pushed an update to my repo that adds dummy Throwable, Exception, and Error classes to my object.d, which made it so you can import Phobos stuff without having to have horrible hacky copies of those files with stuff commented out. (One Phobos file does intentionally stay, though.) I recommend updating your repo with that change.

Let's keep using D in weird places! :)