1. It's not quite trivial to statically disallow use-before-initialization, but it's definitely a solved problem if you disallow returning uninitialized variabl

1. It's not quite trivial to statically disallow use-before-initialization, but it's definitely a solved problem if you disallow returning uninitialized variables. 2. The other option is to disallow declaration without initialization of non-nullable values. If you can't declare an uninitialized foo_vec, then the user can't ever see an invalid foo_vec.