Hello and welcome to another issue of This Week in Rust! Rust is a systems language pursuing the trifecta: safety, concurrency, and speed. 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

Official

• [Inside] What the Error Handling Project Group is Working On

Newsletters

Tooling

• Rust Analyzer Changelog #52
• Knurling-rs Changelog #7

Observations/Thoughts

• FlatBuffer as serialization agnostic IDL
• WTF is Rust? The Illustrated Notes
• First Lines of Rust
• Optimizing Benchpress
• pwintln uwu and other fun with elves and dynamic linkers

Rust Walkthroughs

• Hands-on Rust: Effective Learning through 2D Game Development and Play
• CBOR IoT Data Serialization for Embedded C and Rust
• Basic Interactions with Yew
• Testing your crate C-API
• Rocket Tutorial 03 part II: Proper Testing
• Select Syscall in Rust
• FBSim: football-playing AI agents in Rust
• Building a Recipe Manager - Part 5 - Data Integrity
• Bootstrapping support for the STM32WLE with the Embedded Rust ecosystem
• Recipe for Calling Swift Closures from Asynchronous Rust Code
• [video] A Cool Generic Concurrency Primitive in Rust
• [video] Creative coding in Rust: re-creating a retro screensaver
• [video] (Live Coding) Audio adventures in Rust: Packaging Actix + React app as macOS bundle
• [video] Prototype (Rust tutorial) - Design Patterns

Project Updates

• cargo-mobile: Rust on mobile made easy!
• Welcoming the RustFest Project
• Levenshtein Heuristic in Poi

Miscellaneous

• Strengthening memory safety in Rust: exploring CHERI capabilities for a safe language
• Why AWS loves Rust, and how we'd like to help
• Why Work in Blockchain? - Journey from C++ to Rust Developer
• Flash Animations Live Forever at the Internet Archive [via ruffle.rs, a Flash emulator written in Rust compiled to WASM]
• [video] How to create an awesome Rust GitHub project

Crate of the Week

This week's crate is cargo-intraconv, a cargo subcommand to convert links in rust documentation to the newly stable intra-doc-links format.

Thanks to Alexis Bourget for the suggestion!

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.

• oapth - Meta issue for clean method
• uom - Fix issues with uom CI process

If you are a Rust project owner and are looking for contributors, please submit tasks here.

Updates from Rust Core

345 pull requests were merged in the last week

• never inline naked functions
• fix exhaustiveness in case a byte string literal is used at slice type
• Arena: use specialization to avoid copying data
• add column number support to Backtrace
• add support for custom allocators in Vec
• change slice::to_vec to not use extend_from_slice
• tighten the bounds on atomic Ordering in std::sys::unix::weak::Weak
• Add #[cold] attribute to std::process::abort and alloc::alloc::handle_alloc_error
• impl Default for PhantomPinned
• add trailing_zeros and leading_zeros to non zero types
• add f{32, 64}::is_subnormal
• add core::slice::fill_with
• implement Index and IndexMut for arrays
• make as{_mut,}_slice on array::IntoIter public
• stabilize refcell_take
• stabilize clamp
• stabilise then
• stabilize IpAddr::is_ipv4 and is_ipv6 as const
• stabilize alloc::Layout const functions
• futures: stream: unzip operator
• cargo: allow resolver="1" to explicitly use the old resolver behavior
• rustdoc: give a better error when rustdoc tests fail
• semverver: speed compilation by using .rmeta over .rlib files
• measureme: hardware performance counter support (via rdpmc)

Rust Compiler Performance Triage

• 2020-11-24: 1 Regression, 2 Improvements, 2 mixed

This week saw landing of #79237 which by itself provides no wins but opens the door to support for split debuginfo on macOS. This'll eventually show huge wins as we can likely avoid re-collecting debuginfo while retaining support for lldb and Rust backtraces. #79361 tracks the stabilization of the rustc flag, but the precise rollout to stable users is not yet 100% clear.

Triage done by @jyn514 and @simulacrum.

4 regressions, 4 improvements, 2 mixed results. 5 of them in rollups.

See the full report for more.

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.

RFCs

No RFCs are currently in the final comment period.

Tracking Issues & PRs

No Tracking Issues or PRs are currently in the final comment period.

New RFCs

• Add a new syntax to declare that a trait must always be object-safe

Upcoming Events

Online

• November 26, Edinburgh, UK - Rust in the Polymesh Project - Rust Edinburgh
• November 26, Berlin, DE - Rust Hack and Learn - Berline.rs
• November 26, Tel Aviv-Yafo, IL - Rust Machine Learning On-line Meetup - ODSC Tel Aviv Data Science
• December 1, Buffalo, NY, US - Buffalo Rust User Group - Buffalo Rust Meetup
• December 1, Munich, DE - Rust Remote #4 (CEST) - Rust Munich Meetup
• December 2, Johannesburg, ZA - Monthly Joburg Rust Chat - Johannesburg Rust Meetup
• December 2, Indianapolis, IN, US - Indy.rs - with Social Distancing - Indy Rust
• December 8, Saarbücken, Saarland, DE - Meetup: 6u16 (virtual) - Rust Saar

North America

• December 9, Atlanta, GA, US - Grab a beer with fellow Rustaceans - Rust Atlanta

Asia Pacific

• December 7, Auckland, NZ - Rust AKL - Show and Tell + Introduction to RUst II

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

• Senior Software Engineer, IOx at InfluxData (Remote)

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

Quote of the Week

I know noting about the compiler internals but it looks to me as if 90% of the time is spent pretty-printing LayoutError.

– Vadzim Dambrouski on github

Thanks to mmmmib 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