Announcing Rust 1.95.0

Programming

The Rust team is happy to announce a new version of Rust, 1.95.0. Rust is a programming language empowering everyone to build reliable and efficient software.

If you have a previous version of Rust installed via rustup, you can get 1.95.0 with:

$ rustup update stable

If you don’t have it already, you can get rustup from the appropriate page on our website, and check out the detailed release notes for 1.95.0.

If you’d like to help us out by testing future releases, you might consider updating locally to use the beta channel (rustup default beta) or the nightly channel (rustup default nightly). Please report any bugs you might come across!

What’s in 1.95.0 stable

cfg_select!

Rust 1.95 introduces a cfg_select! macro that acts roughly similar to a compile-time match on cfgs. This fulfills the same purpose as the popular cfg-if crate, although with a different syntax. cfg_select! expands to the right-hand side of the first arm whose configuration predicate evaluates to true. Some examples:

cfg_select! {
    unix => {
        fn foo() { /* unix specific functionality */ }
    }
    target_pointer_width = "32" => {
        fn foo() { /* non-unix, 32-bit functionality */ }
    }
    _ => {
        fn foo() { /* fallback implementation */ }
    }
}

let is_windows_str = cfg_select! {
    windows => "windows",
    _ => "not windows",
};

if-let guards in matches

Rust 1.88 stabilized let chains. Rust 1.95 brings that capability into match expressions, allowing for conditionals based on pattern matching.

match value {
    Some(x) if let Ok(y) = compute(x) => {
        // Both `x` and `y` are available here
        println!("{}, {}", x, y);
    }
    _ => {}
}

Note that the compiler will not currently consider the patterns matched in if let guards as part of the exhaustiveness evaluation of the overall match, just like if guards.

Stabilized APIs