So many good changes in this edition, but I think my favorite is the block tail expression temporaries change, because it means you can finally wrap an expression in a block to drop any temporaries in that expression. This means code like

match process_value(mutex.lock().unwrap()) {
    Ok(()) => { do_stuff(); }
    Err(e) => { log_err(e); }
}

can be fixed to stop holding the lock across the whole match using a simple block, like

match { process_value(mutex.lock().unwrap()) } {
    Ok(()) => { do_stuff(); }
    Err(e) = { log_err(e); }
}

instead of having to extract the scrutinee out into a separate variable.

Big update, lots of good unsafe stuff in the new edition. Setting env vars, extern blocks, attributes, unsafe fn bodies, static mut references banned altogether. All of these things make unsafe code easier, or clearer at least.

Also a huge fan of formatting being tied to editions so it can improve without churn.

It’s nice that the “breaking” changes made in editions tend to be quite small things which unblock larger features later or just make life a tiny bit easier. It seems unlikely for any of these changes to be difficult to accommodate and I imagine cargo fix will do most of the work.

Async closures fixes such a massive hole, stoked to see it stable

THANK GOD we finally have async closures, this was such a pain to work around

One thing I’ve always wondered is why Rust doesn’t use major version increments for major editions like this? The only thing I can think of is the residual fear of the Python 2 -> 3 jump. Or do they just not use semver?

Niko Matsakis made a song (again!)
https://smallcultfollowing.com/babysteps/blog/2025/02/20/rust-2024-is-coming/

Oh the updates and forthcoming undeprecation of std::env::home_dir is a nice change.

I’m happy to see that powerpc64le-unknown-linux-musl is now Tier 2.