Namespace:
I'm pretty nervous, but here is the first: https://github.com/D-Programming-Language/dmd/pull/2952
Good. Keep in mind that at best it will take a month or more for your patch to be accepted. Also patches that implement basic language features like this pass a stringent process of review, that can be laborious and a bit painful. And even after after all that work there's a certain probability of rejection. So you have to build stamina and accumulate patience :-) (Other kind of patches, like D front-end bug fixes or Phobos improvements are faster and often much less painful).
Bye, bearophile