vectorization of a simple loop -- not in DMD?

[ryuukk_]

How do i achieve fast compile speed (results above were on 
windows, on linux i get much faster results):

I maintain healthy project management:

- Templates ONLY when necessary and when the cost is worth the 
time saved in the long term
   - this is why i try to lobby for builtin tagged union instead 
of std.sumtype

- Dependencies, only dependency WITHOUT dependencies, and i keep 
them at the bare minimum!

- Imports of std: i simply don't, and i copy/paste functions i 
need

- I avoid dub packages, instead i prefer import/src path, and i 
chery pick what i need