Case 1 is definitely addressed by the Polonius-related work. There's a post [1] on the official Rust blog from 2023 about that, and this post [2] from Niko Mats

Case 1 is definitely addressed by the Polonius-related work. There's a post [1] on the official Rust blog from 2023 about that, and this post [2] from Niko Matsakis' blog in June 2024 mentions that they were making progress on it, though the timeline has stretched out. [1]: https://blog.rust-lang.org/inside-rust/2023/10/06/polonius-update.html https://blog.rust-lang.org/inside-rust/2023/10/06/polonius-u... [2]: https://smallcultfollowing.com/babysteps/blog/2024/06/02/the-borrow-checker-within/ https://smallcultfollowing.com/babysteps/blog/2024/06/02/the...