Not in a fair number of European countries (France, Germany, ...) - as the op stated you can not cede your copyright which is granted by law. You can't even sign it away (instead have to grant an unlimited + exclusive license to your employer for example)
In France at least you can cede what in English would be called copyright. What you can not sell are the moral rights, and this is the case or a bunch of European countries.
I'm not aware of any European countries where you can not cede reproduction rights / proprietary rights?
Good to know! (That's why I included the qualifier "in many jurisdictions".)
Here, also, Creative Commons' "CC0" declaration is a friend of authors who want to be universally open. CC0 was designed with multiple fallback clauses, intended to also handle copyright systems like those of France or Germany.
CC0 doesn't even necessarily require that you distribute the license text or copyright notice. You can use it as you'd use a public domain work - do anything with it.
