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 constcat, a std::concat!-replacement with support for const variables and expressions.

Thanks to Ross MacArthur for the self-suggestion!

Please submit your suggestions and votes for next week!

Call for Participation

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.

Updates from the Rust Project

386 pull requests were merged in the last week

Rust Compiler Performance Triage

A lot of noise in the results this week; there was an lull in the noise recently, so our auto-inferred noise threshold went down, and thus five PR's were artificially flagged this week (and three supposed improvements were just reverting to the mean). Beyond that, we had three nice improvements: the first to debug builds in #117962 (by ceasing emission of expensive+unused .debug_pubnames and .debug_pubtypes), a second to diesel and serde in #119048 (by avoiding some unnecessary work), and a third to several benchmarks in #117749 (by adding some caching of an internal compiler structure).

Triage done by @pnkfelix. Revision range: 57010939..bf9229a2

6 Regressions, 9 Improvements, 3 Mixed; 5 of them in rollups 67 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

Language Reference

  • No Language Reference RFCs entered Final Comment Period this week.

Unsafe Code Guidelines

  • No Unsafe Code Guideline RFCs entered Final Comment Period this week.

New and Updated RFCs

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 RFCs issued a call for testing 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.

Upcoming Events

Rusty Events between 2023-12-20 - 2024-01-17 🦀



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

The Tianyi-33 satellite is a 50kg class space science experimental satellite equipped with an operating system independently developed by Beijing University of Posts and Telecommunications—the Rust-based dual-kernel real-time operating system RROS. RROS will carry out general tasks represented by tensorflow/k8s and real-time tasks represented by real-time file systems and real-time network transmission on the satellite. It will ensure the normal execution of upper-layer applications and scientific research tasks, such as time-delay measurement between satellite and ground, live video broadcasting, onboard web chat services, pseudo-SSH experiments, etc. This marks the world’s first official application of a Rust-written dual-kernel operating system in a satellite scenario.

Qichen on the RROS web page

Thanks to Brian Kung 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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