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 on Twitter 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.

Updates from Rust Community


Project/Tooling Updates


Rust Walkthroughs


Crate of the Week

This week's crate is coffee_break, the premier crate for those who think Rust compile times are too fast.

Thanks to Jonas Fassbender for the suggestion!

Please submit your suggestions and votes for next week!

Call for Testing

An important step for RFC implementation is for people to experiment with the implementation and give feedback, especially before stabilization. The following RFCs would benefit from user testing before moving forward:

  • No calls for testing were issued this week.

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.

CFP - Speakers

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 submission website through a PR to TWiR.

Updates from the Rust Project

444 pull requests were merged in the last week

Rust Compiler Performance Triage

An overall fairly quiet week with the unfortunate one exception of large instruction count and binary size regressions caused by changes in const evaluation. This was largely balanced out (at least in instruction count) by a group of small improvements, but the compiler did end up 0.2% slower on average across 97 benchmarks.

Triage done by @rylev. Revision range: 21d94a3..73476d


(instructions:u) mean range count
Regressions ❌
1.0% [0.2%, 3.2%] 56
Regressions ❌
0.6% [0.1%, 1.9%] 38
Improvements ✅
-0.8% [-1.5%, -0.2%] 41
Improvements ✅
-1.2% [-5.2%, -0.4%] 13
All ❌✅ (primary) 0.2% [-1.5%, 3.2%] 97

4 Regressions, 6 Improvements, 2 Mixed; 4 of them in rollups 63 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


New and Updated RFCs

Upcoming Events

Rusty Events between 2024-03-27 - 2024-04-24 🦀





North 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.


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

Quote of the Week

"Top contributor" is not a place of glory, it should go to a bot because people should work at a sustainable pace and prioritize touching grass every once in a while. If a person ever works harder than bors, that's a problem!

Carol (Nichols || Goulding) on rust-internals

Thanks to Anton Fetisov for the suggestion!

Please submit quotes and vote for next week!

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

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