Hello and welcome to another issue of This Week in Rust! Rust is a programming language empowering everyone to build reliable and efficient software. This is a weekly summary of its progress and community. Want something mentioned? Tag us at @thisweekinrust.bsky.social on Bluesky or @ThisWeekinRust on mastodon.social, or send us a pull request. Want to get involved? We love contributions.

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Updates from Rust Community

Official

Newsletters

Project/Tooling Updates

Observations/Thoughts

Rust Walkthroughs

Crate of the Week

This week's crate is index_permute, a library for in-place clone-less permutation on mutable slices.

Despite a lack of suggestions this week, llogiq is fairly pleased with his choice.

Please submit your suggestions and votes for next week!

Calls for Testing

An important step for RFC implementation is for people to experiment with the implementation and give feedback, especially before stabilization.

If you are a feature implementer and would like your RFC to appear in this list, add a call-for-testing label to your RFC along with a comment providing testing instructions and/or guidance on which aspect(s) of the feature need testing.

Let us know if you would like your feature to be tracked as a part of this list.

RFCs

Rust

Rustup

If you are a feature implementer and would like your RFC to appear on the above list, add the new call-for-testing label to your RFC along with a comment providing testing instructions and/or guidance on which aspect(s) of the feature need testing.

Call for Participation; projects and speakers

CFP - Projects

Always wanted to contribute to open-source projects but did not know where to start? Every week we highlight some tasks from the Rust community for you to pick and get started!

Some of these tasks may also have mentors available, visit the task page for more information.

If you are a Rust project owner and are looking for contributors, please submit tasks here or through a PR to TWiR or by reaching out on X (formerly Twitter) or Mastodon!

CFP - Events

Are you a new or experienced speaker looking for a place to share something cool? This section highlights events that are being planned and are accepting submissions to join their event as a speaker.

If you are an event organizer hoping to expand the reach of your event, please submit a link to the website through a PR to TWiR or by reaching out on X (formerly Twitter) or Mastodon!

Updates from the Rust Project

425 pull requests were merged in the last week

Compiler

Library

Cargo

Rustdoc

Clippy

Rust-Analyzer

Rust Compiler Performance Triage

Fairly busy week with improvements outweighing regressions. Most of the regressions were considered acceptable given the circumstances (such as landing a long awaited feature). By far the biggest win comes from being a bit smarter about hashing certain information inside of DefPathHash. Since hashing happens quite a lot in th compiler's query system, optimizing when hashing happens can have large performance impacts.

Triage done by @rylev. Revision range: a9fb6103..3f9f20f7

Summary:

(instructions:u) mean range count
Regressions ❌
(primary)		 0.4% [0.1%, 0.9%] 47
Regressions ❌
(secondary)		 0.8% [0.1%, 2.7%] 69
Improvements ✅
(primary)		 -0.8% [-4.1%, -0.2%] 122
Improvements ✅
(secondary)		 -0.7% [-2.5%, -0.0%] 143
All ❌✅ (primary) -0.5% [-4.1%, 0.9%] 169

3 Regressions, 8 Improvements, 8 Mixed; 8 of them in rollups 35 artifact comparisons made in total

Full report here.

Approved RFCs

Changes to Rust follow the Rust RFC (request for comments) process. These are the RFCs that were approved for implementation this week:

  • No RFCs were approved this week.

Final Comment Period

Every week, the team announces the 'final comment period' for RFCs and key PRs which are reaching a decision. Express your opinions now.

Tracking Issues & PRs

Rust
Rust RFCs,
Cargo

No Items entered Final Comment Period this week for Language Team, Language Reference or Unsafe Code Guidelines.

Let us know if you would like your PRs, Tracking Issues or RFCs to be tracked as a part of this list.

New and Updated RFCs

Upcoming Events

Rusty Events between 2025-07-23 - 2025-08-20 🦀

Virtual

Africa

2025-07-23 | Ikot Akpaden, Mkpat Enin, Akwa Ibom State, NG | Rust Nigeria

Asia

Europe

North America

Oceania

South America

If you are running a Rust event please add it to the calendar to get it mentioned here. Please remember to add a link to the event too. Email the Rust Community Team for access.

Jobs

Please see the latest Who's Hiring thread on r/rust

Quote of the Week

In a way, [the] borrow checker also makes interfaces simpler. The rules may be restrictive, but the same rules apply to everything everywhere. I can learn them once, and then know what to expect from every API using references. There are no exceptions in libraries that try to be clever. There are no exceptions for single-threaded programs. There are no exceptions for DLLs. There are no exceptions for programs built with -fpointers-go-sideways. It may be tricky like a game of chess, but I only need to consider the rules of the game, and not odd stuff like whether my opponent glued pieces to the chessboard.

– Kornel Lesiński on hacker news

Thanks to danjl1100 for the suggestion!

Please submit quotes and vote for next week!

This Week in Rust is edited by: nellshamrell, llogiq, cdmistman, ericseppanen, extrawurst, U007D, joelmarcey, mariannegoldin, bennyvasquez, bdillo

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