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. If you find any errors in this week's issue, please submit a PR.

Updates from Rust Community

• RustConf 2023: Call for Proposals

Official

• Language team advisors
• Welcome Tyler Mandry to the Rust language team!
• Governance Reform RFC Announcement

Project/Tooling Updates

• rust-analyzer Changelog #169
• Rust now available for Real-Time Operating System and Hypervisor PikeOS
• Announcing Relm4 v0.5
• Fornjot (code-first CAD in Rust) - Weekly Release - Accidental Side-Effect

Observations/Thoughts

• Why is building a UI in Rust so hard?
• Lightweight, Predictable Async Send Bounds
• Return type notation (send bounds, part 2)
• Faking Algebraic Effects and Handlers With Traits: A Rust Design Pattern
• winnow = toml_edit + combine + nom
• Battle Of The Backends: Rust vs. Go vs. C# vs. Kotlin - inovex GmbH
• The Bull Case for Rust on the Web
• I love building a startup in Rust. I wouldn't pick it again.
• Rust development for the Raspberry PI on Apple Silicon

Rust Walkthroughs

• Learn how to build and deploy a down detector Telegram bot in Rust
• Compile Time Correctness: Type State
• Build a casual side scroller with Rust
• True Observer Pattern with Unsubscribe mechanism using Rust
• Refactoring in Rust: Abstraction with the Newtype Pattern
• Rust to WebAssembly the hard way
• STM32F4 Embedded Rust at the PAC: System Clock Configuration
• Implement base64 encoding using Rust - (Part 1) Base64 for non-unicode characters
• Build a Apache Kafka Producer/Consumer Application in Rust
• Learning Rust by Building a To-Do App
• A Nibble of Quadtrees in Rust
• Embedded Rust on ESP32C3 Board, a Hands-on Quickstart Guide
• How to make a Text Adventure game in Rust - X - More Attributes
• Nothing in Rust
• [ES] Aprendiendo Rust 🦀️ II. Programming a guessing game
• [video] Speed up your Rust code with Rayon
• [video] Making Custom Asset Types: Platformer In Bevy #4
• Implementing a Binary Tree in Rust
• Run WebAssembly from your Rust Program

Research

• The Usability of Advanced Type Systems: Rust as a Case Study

Miscellaneous

• Learn Rust With JetBrains IDEs
• Rust in Rhymes II explainer
• [audio] Lodestone with Wilbur Zhang, Peter Jiang, and Kevin Huang
• Rust Nation UK 2023

Crate of the Week

This week's crate is Darkbird, a high-concurrency real-time in-memory database.

Thanks to DanyalMh 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.

• miri - Get Miri working on ARM again
• man-in-the-middle-proxy - Add Custom headers requests
• Ockam - Create clap command to delete a TCP Outlet on a node
• Ockam - Create clap command to delete a TCP Inlet on a node
• Ockam - Add a Github Action to avoid conflicts in TypeTag ids
• Ockam - Remove the disable/enable_check_credential arguments from ockam tcp-outlet create
• Ockam - Remove the disable/enable_check_credential arguments from ockam tcp-inlet create
• Ockam - Update ockam project addon configure influx-db clap command to ockam project addon configure influxdb

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

Updates from the Rust Project

396 pull requests were merged in the last week

• wasm: register the relaxed-simd target feature
• enable #[thread_local] on armv6k-nintendo-3ds
• add sanitizer support for modern iOS platforms
• add kernel-address sanitizer support for freestanding targets
• add an unstable #[rustc_coinductive] attribute
• added another error to be processed in fallback
• check that built-in callable types validate their output type is Sized (in new solver)
• implement partial support for non-lifetime binders
• deny non-lifetime bound vars in for<..> || closure binders
• don't call with_reveal_all_normalized in const-eval when param_env has inference vars in it
• don't eagerly convert principal to string
• don't recover lifetimes/labels containing emojis as character literals
• don't suggest #[doc(hidden)] trait methods with matching return type
• make codegen choose whether to emit overflow checks
• fix RPITITs in default trait methods (by assuming projection predicates in param-env)
• fix json reexports of different items with same name
• improve the suggestion on future not awaited
• unexpected trait bound not satisfied in HRTB and Associated Type
• make dyn*'s value backend type a pointer
• more accurate spans for arg removal suggestion
• enable CopyProp
• enable instcombine for mutable reborrows
• factor query arena allocation out from query caches
• avoid accessing HIR when it can be avoided
• optimize LazyLock size
• optimize mk_region
• prevent some attributes from being merged with others on reexports
• remove save-analysis
• rework min_choice algorithm of member constraints
• suggest fix for misplaced generic params on fn item
• suggest the correct array length on mismatch
• tighter spans for bad inherent impl self types
• type-directed probing for inherent associated types
• use is_str instead of string kind comparison
• use target instead of machine for mir interpreter integer handling
• use covariance on type relations of field projection types if possible
• use derive attributes for uninteresting traversals
• use id-based thread parking on SOLID
• use restricted Damerau-Levenshtein distance for diagnostics
• use semantic equality for const param type equality assertion
• constify RangeBounds, RangeX::contains and RangeX::is_empty (where applicable)
• implement more methods for vec_deque::IntoIter
• use custom implementation of read_buf in Read for &'a FileDesc
• futures: add AbortHandle::is_aborted()
• cargo: enhance help texts of position args
• only include stable lints in rustdoc::all group
• rustdoc: perform name resolver cleanups
• rustdoc: correctly handle links starting with whitespace
• rustdoc: cleanup doc link extraction
• rustfmt: use correct span for struct generics
• bindgen: add support for enums with the wrapped static functions feature
• clippy: add let_underscore_untyped lint
• clippy: add question_mark_used lint
• clippy: add the transmute_int_to_non_zero lint
• clippy: add significant_drop_tightening lint
• clippy: significant_drop_tightening: evaluate the return expression of a block
• clippy: significant_drop_tightening: ignore inexpensive statements
• clippy: fix false positives for extra_unused_type_parameters
• clippy: stop bytes_nth from suggesting code that does not compile
• clippy: stop doc_markdown requiring backticks on links to external websites
• clippy: box_default: don't omit the type of the removed trait object
• clippy: manual_let_else: do not suggest semantically different replacements
• clippy: manual_let_else: let/else is not divergent by default
• clippy: never_loop Fix false positive with labeled blocks
• clippy: uninlined_format_args: do not inline argument with generic parameters
• clippy: change unusual_byte_groupings to only require byte groupings of equal size
• clippy: do not base map_entry lint suggestion on expanded code
• clippy: fix needless_return incorrect suggestion when returning if sequence
• clippy: ignore synthetic type parameters for extra_unused_type_parameters
• clippy: liberate late-bound regions rather than erasing them in needless_pass_by_value
• rust-analyzer: add v7 metadata support to rust-analyzer
• rust-analyzer: don't assume VSCode internal commands in the server
• rust-analyzer: support UTF-32 position encoding
• rust-analyzer: adjust binding mode inlay hints to render better with @ patterns
• rust-analyzer: bring back hovering call parens for return type info
• rust-analyzer: don't expand macros in the same expansion tree after overflow
• rust-analyzer: don't trigger postfix completion in if block which has an else block
• rust-analyzer: search raw identifiers without prefix
• rust-analyzer: trigger call info for more completions of signature having things

Rust Compiler Performance Triage

Overall a fairly positive week, with few noise-related regressions or improvements and many benchmarks showing significant improvements. The one large regression is limited to documentation builds and has at least a partial fix already planned.

Other wins this week include an average improvement of around 1% in maximum memory usage of optimized builds, and a 2% average reduction in compiled binary sizes. These are fairly significant wins for these metrics.

Triage done by @simulacrum. Revision range: 9bb6e60..3fee48c1

3 Regressions, 3 Improvements, 3 Mixed; 2 of them in rollups 45 artifact comparisons made in total

Full report

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 entered Final Comment Period this week.

Tracking Issues & PRs

• [disposition: merge] rustdoc: search by macro when query ends with !
• [disposition: merge] Stabilize rustdoc --test-run-directory
• [disposition: merge] Treat str as containing [u8] for auto trait purposes

New and Updated RFCs

• [new] Stabilize may_dangle
• [new] Add a [lints] table to Cargo.toml

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 2023-02-22 - 2023-03-22 🦀

Virtual

• 2023-02-23 | Virtual (Charlottesville, VA, US) | Charlottesville Rust Meetup
  • Tock, a Rust based Embedded Operating System
• 2023-02-23 | Virtual (Kassel, DE) | Java User Group Hessen
  • Eine Einführung in Rust (Stefan Baumgartner)
• 2023-02-23 | Virtual (México City, MX) | Rust MX
  • Rust: ¿por qué es una opción adecuada para implantar Blockchain?
• 2023-02-24 | Virtual (Tunis, TN) | Rust Meetup Tunisia
  • Rust Meetup Tunisia - Volume I, Number II
• 2023-02-28 | Virtual (Berlin, DE) | Open Tech School Berlin
  • Rust Hack and Learn
• 2023-02-28 | Virtual (Cardiff, UK) | Rust and C++ Cardiff
  • Rust Nation - What we learnt
• 2023-02-28 | Virtual (Dallas, TX, US) | Dallas Rust
  • Last Tuesday
• 2023-02-28 | Virtual (Munich, DE) | Rust Munich
  • Rust Munich 2023 / 1 - hybrid
• 2023-03-01 | Virtual (Indianapolis, IN, US) | Indy Rust
  • Indy.rs - Michael Baykov on Category Theory & Argument Parsing
• 2023-03-02 | Virtual (Linz, AT) | Rust Linz
  • Rust Meetup Linz - 30th Edition
• 2023-03-07 | Virtual (Buffalo, NY, US) | Buffalo Rust Meetup
  • First Tuesdays
• 2023-03-08 | Virtual (Boulder, CO, US) | Boulder Elixir and Rust
  • Monthly Meetup
• 2023-03-11 | Virtual | Rust GameDev
  • Rust GameDev Monthly Meetup
• 2023-03-14 | Virtual (Berlin, DE) | Berlin.rs
  • Rust Hack and Learn
• 2023-03-15 | Virtual (Cardiff, UK) | Rust and C++ Cardiff
  • Injecting Rust Hooks into a 1999 game binary (unsafe)
• 2023-03-15 | Virtual (Vancouver, BC, CA) | Vancouver Rust
  • Rust Study/Hack/Hang-out
• 2023-03-21 | Virtual (Washington, DC, US) | Rust DC
  • Mid-month Rustful

Asia

• 2023-03-04 | Kyoto, JP | Kansai Rust
  • Fn vs FnMut vs FnOnce

Europe

• 2023-02-23 | Bordeaux, FR | DedoTalk
  • #1 DedoTalk 🎙️ : Rust pour un développeur Python
• 2023-02-23 | Copenhagen, DK | Copenhagen Rust Community
  • Rust metup #33
• 2023-02-23 | Vienna, AT | Rust Vienna
  • Rust Meetup Revived with an Exciting Exploration of Ownership!
• 2023-02-28 | Munich, DE + Virtual | Rust Munich
  • Rust Munich 2023 / 1 - hybrid
• 2023-02-28 | Nijmegen, NL | Rust Nederland
  • Regular track: Rust at RU
  • Student track: Rust at RU
• 2023-03-01 | Cologne, DE | Rust Cologne
  • Rust traits for Fn and profit
• 2023-03-02 | Barcelona, ES | BcnRust
  • 9th BcnRust Meetup: Full Stack
• 2023-03-02 | Wrocław, PL | Rust Wrocław
  • Rust Wrocław Meetup #32
• 2023-03-07 | Bratislava, SK | Bratislava Rust Meetup Group
  • Rust Meetup by Sonalake
• 2023-03-09 | Basel, CH | Rust Basel
  • Rust Meetup #7
• 2023-03-09 | Delft, NL | Rust Nederland
  • Regular track: Embedded Rust
  • Student track: Embedded Rust
• 2023-03-09 | Lyon, FR | Rust Lyon
  • Rust Lyon Meetup #2
• 2023-03-15 | Nürnberg, DE | Rust Nuremberg
  • Walk around Embedded World Exhibition

North America

• 2023-02-23 | Mountain View, CA, US | Mountain View Rust Study Group
  • Rust Meetup at Hacker Dojo
• 2023-03-01 | Austin, TX, US | Rust ATX
  • Rust Lunch
• 2023-03-09 | Lehi, UT, US | Utah Rust
  • Trails, Triumphs, & Travails of Yet-Another-Database-Crate with PJ and Food!

Oceania

• 2023-02-23 | Brisbane, QLD, AU | Rust Brisbane
  • February Meetup
• 2023-02-28 | Canberra, ACT, AU | Canberra Rust User Group
  • February Meetup
• 2023-03-01 | Sydney, NSW, AU | Rust Sydney
  • 🦀 Lightning Talks - We are back!

South America

• 2023-02-22 | Montevideo, UY | Rust Meetup Uruguay
  • Hands on: Lifetimes

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.

Jobs

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

Quote of the Week

It’s enjoyable to write Rust, which is maybe kind of weird to say, but it’s just the language is fantastic. It’s fun. You feel like a magician, and that never happens in other languages.

– Parker Timmerman cited in a TechnologyReview article

Thanks to robin 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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Discuss on r/rust