Rust 1.86.0 pre-release testing

announcements
1

The 1.86.0 pre-release is ready for testing. The release is scheduled for April 3. Release notes can be found here.

You can try it out locally by running:

RUSTUP_DIST_SERVER=https://dev-static.rust-lang.org rustup update stable

The index is https://dev-static.rust-lang.org/dist/2025-04-01/index.html.

The release team is also thinking about changes to our pre-release process: we'd love your feedback on this GitHub issue.

5 Likes
2

slice::get_disjoint_mut has a warning like this: This method does a O(n^2) check to check that there are no overlapping indices, so be careful when passing many indices. But HashMap::get_disjoint_mut does not have this. I thought "maybe they have a way to check it linear time!?!?". Then I checked source, apparently, it just forwarded to hashbrown::HashMap::get_many_mut, which does a O(n^2) check as well. So maybe we should add this warning to HashMap::get_disjoint_mut as well.

9 Likes
3

That's a great catch. Please do file an issue or PR for adding that documentation to HashMap::get_disjoint_mut.

4

Opened an issue.