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

Official

• Announcing Rust 1.75.0

Project/Tooling Updates

• Rustdoc JSON in 2023
• 2023 in Review: Establishing Rust as a Godot 4 language
• Rust9x update: Rust 1.76.0-beta
• Announcing smol-macros, smol-hyper and smol-axum
• Rust Language Bootstrap Team Progress Report 2023
• gitoxide: The year in retrospective, and what's to come

Observations/Thoughts

• A few fast solutions for Advent of Code 2023
• An Update on Writing Memory Safety Bugs
• avatar.png
• Arc vs String, is Arc really faster?
• Iggy.rs - building message streaming in Rust
• Getting Started with Loco in Rust: Part 1
• Printing errors in Rust
• [video] Rust 1.75.0: 54 highlights in 20 minutes!

Miscellaneous

• Test command line application written in Rust
• Open Source Applications written in Rust
• Prompt - read input from Standard Input (STDIN) in Rust
• Testing Your Embedded Rust (feat. embedded-hal-mock and explosions)
• [video] Rust Release Train 1.75
• [video] Rust 1.75.0: 54 highlights in 20 minutes

Crate of the Week

This week's crate is fast_pool, a fast async pool based on the flume channel crate.

Thanks to zhuxiujia for the self-suggestion!

Please submit your suggestions and votes for next week!

Call for Participation; projects and speakers

CFP - Projects

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.

• Hyperswitch - Implement Code cov for local system using makefile
• Hyperswitch - Setup code coverage for local tests & CI
• Hyperswitch - Add domain type for client secret
• Hyperswitch - Have get_required_value to use ValidationError in OptionExt
• Ockam - Use GitHub API to check if the CLI is outdated
• Ockam - refactor to use typed interfaces to implement commands for kafka services
• Ockam - Validate CBOR structs according to the cddl schema for cloud/space and cloud/subscription

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

Updates from the Rust Project

194 pull requests were merged in the last week

• rustc_lint: Enforce rustc::potential_query_instability lint
• rustc_lint: Prevent triplication of various lints
• unused_bindings: also walk bindings created by if-let guards
• change rustc_codegen_ssa's atomic_cmpxchg interface to return a pair of values
• coverage: avoid a possible query stability hazard in CoverageCounters
• coverage: prepare mappings separately from injecting statements
• coverage: unexpand spans with find_ancestor_inside_same_ctxt
• don't drop a hir node after lowering
• don't suggest writing a bodyless arm if the pattern can never be a never pattern
• don't validate / lint MIR before each pass
• enable profiler in dist-powerpc-linux
• fix infinite loop in <BoundConstness as Display>
• fix invalid check-cfg Cargo feature diagnostic help
• fix parenthesization of subexprs containing statement boundary
• fix: correct the args for disambiguate the associated function diagnostic
• fix: diagnostic for casting reference to slice
• introduce const Trait (always-const trait bounds)
• simplify Parser::ident_or_error
• simplify bootstrap --check-cfg arguments
• solaris support on bootstrap lock
• subtree sync for rustc_codegen_cranelift
• suggest => → >= in comparisons
• utilize the unused llvm-tools option
• miri: fix integer overflow ICEs from round_up_to_next_multiple_of
• miri: NaN non-determinism for intrinsics and libm functions
• miri: support for tempfile crate on UNIX hosts
• implement constant propagation on top of MIR SSA analysis
• only store StableCrateId once in DefPathTable
• shrink span encoding further
• openbsd: available_parallelism: use the right API
• cargo: cargo add - fix for adding features from repository with multiple packages
• cargo: cargo fix: always inherit the jobserver
• cargo: fix fix::fix_in_dependency to not rely on rustc
• cargo: rustfix: support inserting new lines
• rustdoc-search: count path edits with separate edit limit
• rustdoc: treat query string + as space
• clippy: check for redundant matches! with Ready, Pending, V4, V6
• clippy: [doc_markdown]: Add "WebGL2", "WebGPU" to default doc_valid_idents
• clippy: add external macro checks to iter_without_into_iter and into_iter_without_iter
• clippy: don't lint default_numeric_fallback on return and local assigned macro calls with type stated
• clippy: extend unconditional_recursion to check for ToString implementations
• clippy: add manual_is_variant_and lint
• clippy: add new lint pub_underscore_fields
• clippy: suggest str.lines when splitting at hard-coded newlines
• clippy: make mutex_atomic more type aware
• clippy: new lint: empty_enum_variants_with_brackets
• clippy: new lint: thread_local_initializer_can_be_made_const
• clippy: new lint: eager_transmute
• clippy: remove mitigations for incorrect node args
• rust-analyzer: fix SyntaxContextID using incorrect self IDs
• rust-analyzer: fix out-of-bounds panic in some macros due to unhandled self_ref

Rust Compiler Performance Triage

Overall, this week had very few regressions and a moderate amount of improvements. The two biggest improvements came in how metadata was being encoded including a change to only store StableCrateId once in DefPathTable which yielded a 0.3% average improvement across 79 different benchmarks.

Triage done by @rylev. Revision range: 1ab783112..67b6975

Summary:

2 Regressions, 3 Improvements, 1 Mixed; 0 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:

• 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 for tuples and unit by type with ()

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

• RFC: New range types for Edition 2024
• Add RFC to discuss RustConf 2024 Steering Committee

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 2024-01-03 - 2024-01-31 🦀

Virtual

• 2024-01-03 | Virtual (Indianapolis, IN, US) | Indy Rust
  • Indy.rs - with Social Distancing
• 2024-01-06 | Virtual (Kampala, UG) | Rust Circle
  • Rust Circle Meetup
• 2024-01-09 | Virtual (Dallas, TX, US) | Dallas Rust
  • Second Tuesday
• 2024-01-11 | Virtual (Charlottesville, NC, US) | Charlottesville Rust Meetup
  • Crafting Interpreters in Rust Collaboratively
• 2024-01-11 | Virtual (Nürnberg, DE) | Rust Nuremberg
  • Rust Nürnberg online
• 2024-01-16 | Virtual (Washington, DC, US) | Rust DC
  • Mid-month Rustful
• 2024-01-17 | Virtual (Vancouver, BC, CA) | Vancouver Rust
  • Rust Study/Hack/Hang-out
• 2024-01-18 | Virtual (Berlin, DE) | OpenTechSchool Berlin
  • Rust Hack and Learn
• 2024-01-21 | Virtual | Rust Maven
  • Web development with Rocket - In English
• 2024-01-23 | Virtual (Halifax, NS, CA) | Rust Halifax
  • Rust&Tell - Halifax
• 2024-01-24 | Virtual (Berlin, DE) | WeAreDevelopers Community
  • WeAreDevelopers LIVE - Rust Day
• 2024-01-25 | Virtual (Charlottesville, NC, US) | Charlottesville Rust Meetup
  • Crafting Interpreters in Rust Collaboratively
• 2024-01-28 | Virtual (Wrocław, PL) | Stacja IT Wrocław
  • Wprowadzenie do języka Rust
• 2024-01-30 | Virtual (Buffalo, NY, US) | Buffalo Rust User Group
  • Buffalo Rust User Group
• 2024-01-30 | Virtual (Dallas, TX, US) | Dallas Rust
  • Last Tuesday

Europe

• 2024-01-10 | Cologne, DE | Rust Cologne
  • Game development in Rust
• 2024-01-11 | Reading, UK | Reading Rust Workshop
  • Reading Rust Meetup at Browns
• 2024-01-11 | Wrocław, PL | Rust Wrocław
  • Rust Meetup #36
• 2024-01-13 | Tampere, FI | Finland Rust-lang Group
  • January Meetup
• 2024-01-16 | Leipzig, DE | Rust - Modern Systems Programming in Leipzig
  • Async in Rust
• 2024-01-17 | Praha / Prague, CZ | Rust Prague
  • Rust Meetup Renewed
• 2024-01-17 | Zurich, CH | Rust Zurich
  • How to Community - January Meetup
• 2024-01-23 | Aarhus, DK | Rust Aarhus
  • Hack and Learn

North America

• 2024-01-06 | Boston, MA, US | Boston Rust Meetup
  • Beacon Hill Rust Lunch
• 2024-01-08 | Chicago, IL, US | Deep Dish Rust
  • Rust Hack Night
• 2024-01-09 | Seattle, WA, US | Cap Hill Rust Coding/Hacking/Learning
  • Rusty Coding/Hacking/Learning Night
• 2024-01-09 | Minneapolis, MN, US | Minneapolis Rust Meetup
  • Minneapolis Rust Meetup Happy Hour
• 2024-01-09 | New York, NY, US | Rust NYC
  • Rust NYC Monthly Meetup: A Deep Dive into Tower by Adrien Guillo
• 2024-01-14 | Cambridge, MA, US | Boston Rust Meetup
  • Alewife Rust Lunch
• 2024-01-16 | San Francisco, CA, US | San Francisco Rust Study Group
  • Rust Hacking in Person
• 2024-01-17 | Chicago, IL, US | Deep Dish Rust
  • Rust Happy Hour
• 2024-01-18 | Seattle, WA, US | Seattle Rust User Group
  • Seattle Rust User Group Meetup
• 2024-01-22 | Boston, MA, US | Boston Rust Meetup
  • North End Rust Lunch
• 2024-01-24 | Austin, TX, US | Rust ATX
  • Rust Lunch - Fareground
• 2024-01-30 | Cambridge, MA, US | Boston Rust Meetup
  • Harvard Square Rust Lunch

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

Some people don't believe in life after death... Rust doesn't believe in magic after compilation.

– Stephan Sokolow on rust-users

Thanks to Todd Fleming 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