I've put together a proposal for using covariant return types in Array::type() in the C++ library. I wanted to get some feedback before putting together a PR in case it's too controversial or would require to much re-factoring of the code:
https://docs.google.com/document/d/14mLO9uNIcrb-yTj_byBxwJeYbGy88JS9fQ6aOa46XRc/edit?usp=sharing It would be nice to use Google Doc's comment feature, but I would imagine it may be safer to memorialize the discussion here on the mailing list.
