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.

This week's crate is mailtutan, a simulating SMTP server.

Thanks to Mohsen Alizadeh 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

346 pull requests were merged in the last week

Rust Compiler Performance Triage

Our build pipeline got sped up by PR #112012, which side-steps one of the rustc rebuilds we were suffering with before. (There is further potential speed-up by caching LLVM, as noted by on that PR.) Other than that, various small regressions that are largely noise, as well as one unexpected increase in binary sizes from PR #109005 that we should follow up on.

Triage done by @pnkfelix. Revision range: adc719d7..4bd4e2ea

7 Regressions, 3 Improvements, 5 Mixed; 5 of them in rollups 46 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:

Return position impl Trait in traits

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.

RFCs

No RFCs entered Final Comment Period this week.

Tracking Issues & PRs

[disposition: merge] Implement Sync for mpsc::Sender
[disposition: merge] resolve: Remove artificial import ambiguity errors
[disposition: merge] Relax implicit T: Sized bounds on BufReader<T>, BufWriter<T> and LineWriter<T>

New and Updated RFCs

[new] Infered types

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 2023-06-14 - 2023-07-12 🦀

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.