The part of the blog post where it says

> What’s with all these new reference types? > All of these are speculative ideas

makes it pretty clear to me that they are indeed not yet part of Rust but instead something people have been thinking about adding. The rest of the post discusses how these would work if they were implemented.

Right. The &pin, &own, and &uninit in the article (or rather everything except & and &mut in that table) do not exist in Rust.

I have seen &pin being proposed recently [1], first time I'm seeing the others.

[1] https://blog.rust-lang.org/2025/11/19/project-goals-update-o...

Own and uninit have been in discussions wrt in place construction. The Rust in the Linux kernel project seems to be the motivating use case for this that really got the effort going recently.