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.

This Week in Rust is openly developed on GitHub and archives can be viewed at this-week-in-rust.org. If you find any errors in this week's issue, please submit a PR.

Want TWIR in your inbox? Subscribe here.

Updates from Rust Community

Official

Newsletters

Project/Tooling Updates

Observations/Thoughts

Rust Walkthroughs

Crate of the Week

This week's crate is primitive_fixed_point_decimal, a crate of real fixed-point decimal types.

Thanks to Wu Bingzheng for the self-suggestion!

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.

No Calls for papers or presentations were submitted this week.

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

448 pull requests were merged in the last week

Compiler

Library

Cargo

Rustdoc

Clippy

Rust-Analyzer

Rust Compiler Performance Triage

A week dominated by the landing of a large patch implementing RFC#3729 which unfortunately introduced rather sizeable performance regressions (avg of ~1% instruction count on 111 primary benchmarks). This was deemed worth it so that the patch could land and performance could be won back in follow up PRs.

Triage done by @rylev. Revision range: 45acf54e..42245d34

Summary:

(instructions:u) mean range count
Regressions ❌
(primary)		 1.1% [0.2%, 9.1%] 123
Regressions ❌
(secondary)		 1.0% [0.1%, 4.6%] 86
Improvements ✅
(primary)		 -3.8% [-7.3%, -0.3%] 2
Improvements ✅
(secondary)		 -2.3% [-18.5%, -0.2%] 44
All ❌✅ (primary) 1.0% [-7.3%, 9.1%] 125

2 Regressions, 4 Improvements, 10 Mixed; 7 of them in rollups 40 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

No Items entered Final Comment Period this week for Cargo, Language Reference, Language Team 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

  • No New or Updated RFCs were created this week.

Upcoming Events

Rusty Events between 2025-06-25 - 2025-07-23 🦀

Virtual

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

Our experience is that no matter how many safeguards you put on code, there’s no cure-all that prevents bad programming. Of course, to take the contrary argument, seat belts don’t stop all traffic fatalities, but you could just choose not to have accidents. So we do have seat belts. If Rust can prevent some mistakes or malicious intent, maybe it’s worth it even if it isn’t perfect.

– Al Williams on hackaday

Thanks to Kill The Mule 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

Email list hosting is sponsored by The Rust Foundation

Discuss on r/rust