Huh? None of that will be in 2.12 except unification, and that's already planned for backporting to 2.11 (and you can just use the compiler plugin until then).

> I don't want to be stuck on an old version as the language moves forward.

How are you going to be stuck? You might need to stay on 2.11 a bit longer until Google gets their shit together. Most likely this will be during 2.12. Sure, you might miss the first few minor releases of 2.12 ... but stuck?