Announcing Rust 1.75.0

Dec. 28, 2023 · The Rust Release Team

The Rust team is happy to announce a new version of Rust, 1.75.0. 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 1.75.0 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 1.75.0.

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 1.75.0 stable

async fn and return-position impl Trait in traits

As announced last week, Rust 1.75 supports use of async fn and -> impl Trait in traits. However, this initial release comes with some limitations that are described in the announcement post.

It's expected that these limitations will be lifted in future releases.

Pointer byte offset APIs

Raw pointers (*const T and *mut T) used to primarily support operations operating in units of T. For example, <*const T>::add(1) would add size_of::<T>() bytes to the pointer's address. In some cases, working with byte offsets is more convenient, and these new APIs avoid requiring callers to cast to *const u8/*mut u8 first.

Code layout optimizations for rustc

The Rust compiler continues to get faster, with this release including the application of BOLT to our binary releases, bringing a 2% mean wall time improvements on our benchmarks. This tool optimizes the layout of the library containing most of the rustc code, allowing for better cache utilization.

We are also now building rustc with -Ccodegen-units=1, which provides more opportunity for optimizations in LLVM. This optimization brought a separate 1.5% wall time mean win to our benchmarks.

In this release these optimizations are limited to x86_64-unknown-linux-gnu compilers, but we expect to expand that over time to include more platforms.

Stabilized APIs

These APIs are now stable in const contexts:

Other changes

Check out everything that changed in Rust, Cargo, and Clippy.

Contributors to 1.75.0

Many people came together to create Rust 1.75.0. We couldn't have done it without all of you. Thanks!