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? Tweet us at @ThisWeekInRust or send us a pull request. Want to get involved? We love contributions.

This Week in Rust is openly developed on GitHub. 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 serde_with, a crate of helper macros to ease implementing serde traits for your types.

Thanks to piegames for the suggestion!

Please submit your suggestions and votes for next week!

Call for Participation

Always wanted to contribute to open-source projects but didn't 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

353 pull requests were merged in the last week

Rust Compiler Performance Triage

A week where improvements outweigh regressions. The highlight of the week is the change to split out LLVM profile guided optimization (PGO) and using clang 13 to compile LLVM which led to improvements in many real world crates (e.g., cargo) in the range of 10%. Most regressions were limited and at most in the less than 1% range. We are seeing more performance changes in rollups which are supposed to be performance neutral. We'll have to decide how to best address this.

Triage done by @rylev. Revision range: 9475e609..d45ed750

3 Regressions, 4 Improvements, 2 Mixed; 2 of them in rollups; 34 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 RFCs

Upcoming Events


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.

Rust Jobs


Connected Cars






Tweet us at @ThisWeekInRust to get your job offers listed here!

Quote of the Week

The biggest failure in Rust‘s communication strategy has been the inability to explain to non-experts that unsafe abstractions are the point, not a sign of failure.

withoutboats on twitter

Thanks to Alice Ryhl for the suggestion!

Please submit quotes and vote for next week!

This Week in Rust is edited by: nellshamrell, llogiq, and cdmistman.

Discuss on r/rust