Move data-structures to a namespace

[jumpnbrownweasel]

There has been lots of discussion about this but it’s not always easy to find. Here’s one example, starting with this post in a larger thread:

Why are allocator interfaces and implementations split across `std.mem` / `std.heap`, while IO is colocated under `std.Io`?

I’d be a bit more in favor of std.alloc. It’s an abbreviation, but so is std.mem. Although the standard library is moving more toward “fat types”, Io being the prime example, by which I mean: containers which can be instantiated, but also have a whole namespace of other goodies, I’m not convinced this is the best way to do it. When you look at the docs for std, there’s a bunch of types at the top, and a bunch of namespaces below it. Some of the types are just types: if you click on ArrayList,…