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

Project/Tooling Updates

• Announcing axum 0.7.0
• Announcing general availability of the AWS SDK for Rust
• ripgrep 14.0.0
• Improved Multithreading in wgpu - Arcanization Lands on Trunk
• Introducing SALT: A Rust error tutor, seeking participants in a study of errors!
• Bionic GPT - Chat GPT replacement built in Rust
• cargo-run-bin: Why does everyone install crates globally?
• CXX-Qt: On the Road to Stability, improved signals support and more in release 0.6
• Oatmeal: Terminal UI to chat with large language models (LLM) using different model backends, and integrations with your favourite editors!

Observations/Thoughts

• Project Goals
• poll_next
• [video] but what is 'a lifetime?
• [audio] Recruiting in Rust with Cedric Sellmann

Rust Walkthroughs

• Designing a SIMD Algorithm from Scratch
• Why Enums in Rust feel so much better
• How I Use Declarative Macros in Rust
• Embassy on ESP: Getting Started
• Intro to LLVM and MLIR with Rust and Melior
• Investigating crazy compile times
• [video] Rust Course (Part 2) (Bahasa Indonesia).

Research

• Refinement Proofs in Rust Using Ghost Locks
• Semantic fuzzing of the Rust compiler and interpreter

Miscellaneous

• Read arbitrary YAML files in Rust
• Create a Lambda in Rust using Terraform

Crate of the Week

This week's crate is tokio-graceful, a library for graceful shutdown of tokio-based async servers.

Thanks to Glen De Cauwsemaecker for the 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.

• Hyperswitch - [REFACTOR]: [Nuvei] MCA metadata validation
• Hyperswitch - [Features]: [Noon] Sync with Hyperswitch Reference
• Hyperswitch - [Features]: [Payme] Sync with Hyperswitch Reference
• Hyperswitch - [BUG]: MCA metadata deserialization failures should be 4xx
• Hyperswitch - [REFACTOR]: [Stripe] Error Message For Connector Implementation
• Ockam - Library - Slim down the NodeManagerWorker for node / node status
• Ockam - Command - refactor to use typed interfaces to implement commands for kafka services
• Ockam - Library - Validate CBOR structs according to the cddl schema for nodes/models/transport and nodes/models/workers
• r3bl-open-core - [tuify] API change the return type of select_from_list() 3
• r3bl-open-core - Improve "Bug report" issue template

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

Updates from the Rust Project

405 pull requests were merged in the last week

• stabilize dyn upcasting coercion (RFC #3324)
• add an experimental feature gate for function delegation
• enable Rust to use the EHCont security feature of Windows
• enable profiler in dist-powerpc64-linux
• enable the Arm Cortex-A53 errata mitigation on aarch64-unknown-none
• remove now deprecated target x86_64-sun-solaris
• EvalCtxt::commit_if_ok don't inherit nested goals
• intercrate_ambiguity_causes: handle self ty infer + reservation impls
• add Span to TraitBoundModifier
• add debug_assert_nounwind and convert assert_unsafe_precondition
• add allow-by-default lint for unit bindings
• allow defining opaques in check_coroutine_obligations
• call FileEncoder::finish in rmeta encoding
• coverage: simplify building coverage expressions based on sums
• do not erase late bound regions when selecting inherent associated types
• don't ICE when ambiguity is found when selecting Index implementation in typeck
• don't ICE when encountering placeholders in implied bounds computation
• don't consider generic args of supertrait in deref_into_dyn_supertrait lint
• don't require intercrate mode for negative coherence
• eagerly compute output_filenames
• fix early param lifetimes in generic_const_exprs
• fixes error count display is different when there's only one error left
• improve tool-only help for multiple #[default] variants
• make PlaceholderReplacer shallow_resolver and recur when infer vars
• note about object lifetime defaults in does not live long enough error
• print query map for deadlock when using parallel front end
• relate Inherent Associated Types using eq
• remove --check-cfg checking of command line --cfg args
• remove HirId from QPath::LangItem
• separate NaN/Inf floats with _
• suggest swapping the order of ref and box
• the unadjusted ABI needs to pass aggregates by-value
• tighten up link attributes for llvm-wrapper bindings
• typeck break expr even if break is illegal
• use an absolute path to the NUL device
• when failing to import core, suggest std
• add VarDebugInfo to Stable MIR
• add support for global allocation in smir
• fix smir's Ty::Ref pretty printing
• expand Miri's BorTag GC to a Provenance GC
• validate there are no critical call edges in optimized MIR
• miri: GC the dead_alloc_map too
• miri: check that target features required by LLVM intrinsics are enabled
• miri: refactor float_to_int_checked to remove its generic parameter and reduce code duplication a bit
• cache flags for ty::Const
• indicate that multiplication in Layout::array cannot overflow
• rewrite exhaustiveness in one pass
• AmbiguityCause should not eagerly format strings
• specialize SpecFromElem for ()
• refactor binary_search_by to use conditional moves
• stabilize ptr::addr_eq
• add BufRead::skip_until
• kmc-solid: I/O safety
• add Duration::abs_diff
• non null convenience ops
• hashbrown: specialize fold implementation of iterators
• cranelift: implement another batch of vendor intrinsics
• cargo: refactor(toml): Better abstract inheritance details
• cargo: exited with hard error when custom build file no existence or not in package
• cargo: add CARGO_RUSTC_CURRENT_DIR (unstable)
• cargo: use custom error instead of anyhow
• cargo: review and remove ignored tests in rustfix
• cargo: try running on windows
• rustdoc-search: add support for traits and associated types
• rustdoc-search: avoid infinite where clause unbox
• rustdoc-search: simplify checkPath and sortResults
• rustdoc: sort unstable items last instead of first
• rustfix: add notice that rustfix has moved
• clippy: TypeckResults::node_type() can be used inside of bodies
• clippy: deprecated_semver: Allow #[deprecated(since = "TBD")]
• clippy: manual_try_fold: check that fold is really Iterator::fold
• clippy: missing_asserts_for_indexing: work with bodies instead of blocks separately
• clippy: needless_return_with_question_mark: don't lint if never type is used for coercion
• clippy: ptr_arg: recognize methods that also exist on slices
• clippy: add new check_private_items config
• clippy: create new lint option_map_or_err_ok
• clippy: don't suggest a.mul_add(b, c) if parameters are not float
• clippy: extend result_map_or_into_option lint to handle Result::map_or_else(|_| None, Some)
• clippy: fix box_default behaviour with empty vec! coming from macro arg
• clippy: fix iter_kv_map false positive into_keys and into_values suggestion
• clippy: improve error messages format
• clippy: remove underscore check for manual_non_exhaustive lint
• clippy: suggest alternatives to iterate an array of ranges
• clippy: use absolute path for declare_tool_lint in declare_clippy_lint
• rust-analyzer: cancelable initialization
• rust-analyzer: editor/code: add option to suppress internal error notifications
• rust-analyzer: ensure renames happen after edit
• rust-analyzer: fix variant resolve for type alias
• rust-analyzer: fix: add fallback for completion label details
• rust-analyzer: fix: better resolve assoc item with type bound
• rust-analyzer: fix: dedup duplicate crates with differing origins in CrateGraph construction
• rust-analyzer: fix: remove parenthesis should ensure space
• rust-analyzer: improve completion label details display
• rust-analyzer: replace option.map(cond) == Some(true) with option.is_some_and(cond)

Rust Compiler Performance Triage

A good week, despite a few PRs that pnkfelix opted not to mark as triaged. In particular, a broad set of primary benchmarks improved, due to improvements to resolve (PR #118188) and a one-pass rewrite of exhaustiveness (PR #117611).

Triage done by @pnkfelix. Revision range: 4f3da903..df0295f0

1 Regressions, 5 Improvements, 5 Mixed; 2 of them in rollups 84 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

• [disposition: merge] Macro fragment specifiers edition policy

Tracking Issues & PRs

• [disposition: merge] [rustdoc] Add highlighting for comments in items declaration
• [disposition: merge] generalize: handle occurs check failure in aliases

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: constants in patterns
• Add RFC combining Infra and Release teams

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 2023-11-29 - 2023-12-27 🦀

Virtual

• 2023-11-29 | Virtual (Cardiff, UK) | Rust and C++ Cardiff
  • Atomics & Locks Book Club Final Chapter! (Chapter 10)
• 2023-11-30 | Virtual (Charlottesville, NC, US) | Charlottesville Rust Meetup
  • Crafting Interpreters in Rust Collaboratively
• 2023-11-30 | Virtual (Dublin, IE) | Rust Dublin
  • Automating expertise with cargo-semver-checks
• 2023-12-01 | Virtual (Cardiff, UK) | Rust and C++ Cardiff
  • Rust & C++ Christmas Game Jam Kick-Off!
• 2023-12-02 | Virtual (Kampala, UG) | Rust Circle Kampala
  • Rust Circle Meetup
• 2023-12-05 | Virtual (Berlin, DE) | OpenTechSchool Berlin
  • Rust Hack and Learn | Mirror
• 2023-12-05 | Virtual (Buffalo, NY, US) | Buffalo Rust Meetup
  • Buffalo Rust User Group, First Tuesdays
• 2023-12-06 | Virtual (Indianapolis, IN, US) | Indy Rust
  • Indy.rs - with Social Distancing
• 2023-12-10 | Virtual (Cardiff, UK) | Rust and C++ Cardiff
  • Rust & C++ Christmas Game Jam Finale
• 2023-12-12 | Virtual | Mainmatter
  • Workshop: Telemetry for Rust applications
• 2023-12-12 | Virtual (Dallas, TX, US) | Dallas Rust
  • Second Tuesday
• 2023-12-14| Virtual (Charlottesville, NC, US) | Charlottesville Rust Meetup
  • Crafting Interpreters in Rust Collaboratively
• 2023-12-14 | Virtual (Nuremberg, DE) | Rust Nuremberg
  • Rust Nürnberg online
• 2023-12-17 | Virtual (Tel Aviv, IL) | Code Mavens
  • Don't panic! - Our journey to error handling in Rust
• 2023-12-18 | Virtual (Munich, DE) | Rust Munich
  • Rust Munich 2023 / 5 - hybrid
• 2023-12-19 | Virtual (Berlin, DE) | OpenTechSchool Berlin
  • Rust Hack and Learn | Mirror
• 2023-12-20 | Virtual (Vancouver, BC, CA) | Vancouver Rust
  • Adventures in egui app dev

Asia

• 2023-12-16 | Delhi, IN | Rust Delhi
  • Meetup #4

Europe

• 2023-11-30 | Brussels, BE | Lambda Brussels
  • Lambda Brussels
• 2023-11-30 | Copenhagen, DK | Copenhagen Rust Community
  • Rust metup #42 sponsored by Nine A/S
• 2023-11-30 | Vienna, AT | Rust Vienna
  • Rust Vienna Meetup - November
• 2023-11-30 | Zurich, CH | Rust Zurich
  • November Meetup
• 2023-12-06 | Cologne, DE | Rust Cologne
  • December Meetup
• 2023-12-07 | Aarhus, DK | Rust Aarhus
  • Rust and Talk at Danske Commodities
• 2023-12-07 | Lille, FR | Rust Lille
  • Rust Lille #5
• 2023-12-14 | Augsburg, DE | Rust - Modern Systems Programming in Leipzig
  • Augsburg Rust Meetup #4
• 2023-12-18 | Munich, DE + Virtual | Rust Munich
  • Rust Munich 2023 / 5 - hybrid
• 2023-12-19 | Heidelberg, DE | Nix Your Bugs & Rust Your Engines
  • Nix Your Bugs & Rust Your Engines #1
• 2023-12-19 | Leipzig, DE | Rust - Modern Systems Programming in Leipzig
  • Tauri, an Electron-alternative

North America

• 2023-11-29 | Chicago, IL, US | Deep Dish Rust
  • Rust Hack Night
• 2023-11-30 | Mountain View, CA, US | Mountain View Rust Meetup
  • Rust Meetup at Hacker Dojo
• 2023-12-07 | Seattle, WA, US | Seattle Rust User Group
  • Seattle Rust User Group Meetup
• 2023-12-12 | Seattle, WA, US | Cap Hill Rust Coding/Hacking/Learning
  • Rusty Coding/Hacking/Learning Night
• 2023-12-12 | New York, NY, US | Rust NYC
  • Rust NYC Monthly Mixer: Share, Show, & Tell! 🦀
• 2023-12-19 | San Francisco, CA, US | San Francisco Rust Study Group
  • Rust Hacking in Person

Oceania

• 2023-11-28 | Canberra, ACT, AU | Rust Canberra
  • November Meetup
• 2023-12-05 | Aukland, NZ | Rust AKL
  • Rust AKL: Advanced Async Tricks + Interruptible Software
• 2023-12-11 | Perth, WA, AU | Rust Perth Meetup Group
  • Rust End of Year Event

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

I'd like to report that Rust's compile times were OK today and yesterday and the day before.

I'll keep you posted.

– ZiCog about slow Rust compile times on rust-users

Thanks to Michael Bryan 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.

Email list hosting is sponsored by The Rust Foundation

Discuss on r/rust