@ yglukhov While you make good points, I would argue that D feels more ... ... "complete". Don't get me wrong, I like Nim. However D is self hosted, and it has nice features like CTFE, static ifs and Mixins etc. I'm currently reading through the Nim book so I don't quite know if Nim has these.
Both D and Nim are great imo, but D has had the blessing of genius minds like Andrei Alexandrescu and Walter Bright. Tldr: Haven't finished the book yet, Nim looks pretty promising but I can't compare them yet. If anything, both these are easier to work with than C++.
