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 X (formerly 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.

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Updates from Rust Community

Project/Tooling Updates

• An update on Apple M1/M2 GPU drivers
• Announcing Toasty, an async ORM for Rust
• gitoxide - October 2024
• Glues v0.4 - MongoDB support and Vim editing features
• Meilisearch 1.11 - AI-powered search & federated search improvements

Observations/Thoughts

• Toward safe transmutation in Rust
• The performance of the Rust compiler
• A new approach to validating test suites
• Why You Shouldn't Arc a HashMap in Rust
• Implementing the Tower Service Trait
• Best Practices for Derive Macro Attributes in Rust
• Trimming down a rust binary in half
• A deep look into our new massive multitenant architecture
• Unsafe Rust Is Harder Than C
• Generators with UnpinCell
• Which LLM model is best for generating Rust code?
• Learnings from Contributing to the Rust Project
• Dyn Box Vs. Generics: What is the best approach for achieving conditional generics in Rust?

Rust Walkthroughs

• Basic Integer Compression

Miscellaneous

• Rust Prism
• [audio] Rust vs. C++ with Steve Klabnik and Herb Sutter
• [audio] What's New in Rust 1.76, 1.77, and 1.78
• [video] Talk on Chrome's new Rust font stack, fontations
• [video] Architecting a Rust Game Engine (with Alice Cecile)
• [video] Gitoxide: What it is, and isn't - Sebastian Thiel

Crate of the Week

This week's crate is tower-http-client, a library of middlewares and various utilities for HTTP-clients.

Thanks to Aleksey Sidorov for the self-suggestion!

Please submit your suggestions and votes for next week!

Calls 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:

RFCs

• No calls for testing were issued this week.

Rust

• No calls for testing were issued this week.

Rustup

• No calls for testing were issued 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.

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.

• wtx - [HTTP/2] Investigate requests latency

If you are a Rust project owner and are looking for contributors, please submit tasks here or through a PR to TWiR or by reaching out on X (formerly Twitter) or Mastodon!

CFP - Events

Are you a new or experienced speaker looking for a place to share something cool? This section highlights events that are being planned and are accepting submissions to join their event as a speaker.

If you are an event organizer hoping to expand the reach of your event, please submit a link to the website through a PR to TWiR or by reaching out on X (formerly Twitter) or Mastodon!

Updates from the Rust Project

447 pull requests were merged in the last week

• add wasm32v1-none target
• AIX: use /dev/urandom for random implementation
• rustc_target: Add pauth-lr aarch64 target feature
• add a note for ? on a impl Future<Output = Result<..>> in sync function
• add support for ~const item bounds
• consider param-env candidates even if they have errors
• const stability checks v2
• coverage: consolidate creation of covmap/covfun records
• coverage: don't rely on the custom traversal to find enclosing loops
• coverage: emit LLVM intrinsics using the normal helper method
• coverage: pass coverage mappings to LLVM as separate structs
• deeply normalize TypeTrace when reporting type error in new solver
• deny calls to non-#[const_trait] methods in MIR constck
• do not remove .cargo directory
• don't stage-off to previous compiler when CI rustc is available
• emit future-incompatibility lint when calling/declaring functions with vectors that require missing target feature
• enable LSX feature for LoongArch Linux targets
• error on alignments greater than isize::MAX
• expand: stop using artificial ast::Item for macros loaded from metadata
• fixup Windows verbatim paths when used with the include! macro
• hashStable for rustc_feature::Features: stop hashing compile-time constant
• lint against getting pointers from immediately dropped temporaries
• move cmp_in_dominator_order out of graph dominator computation
• pass constness with span into lower_poly_trait_ref
• prevent overflowing enum cast from ICEing
• refactor change detection for rustdoc and download-rustc
• replace an FTP link in comments with an equivalent HTTPS link
• replace some LLVMRust wrappers with calls to the LLVM C API
• represent hir::TraitBoundModifiers as distinct parts in HIR
• represent trait constness as a distinct predicate
• round negative signed integer towards zero in iN::midpoint
• simplify force-recompile logic for "library"
• simplify param handling in resolve_bound_vars
• taking a raw ref (&raw (const|mut)) of a deref of pointer (*ptr) is always safe
• use Enabled{Lang,Lib}Feature instead of n-tuples
• validate args are correct for UnevaluatedConst, ExistentialTraitRef/ExistentialProjection
• x86 target features: make pclmulqdq imply sse2
• x86-32 float return for 'Rust' ABI: treat all float types consistently
• miri: add option for generating coverage reports
• miri: android: added syscall support
• miri: clear eval_libc errors from unix shims
• miri: consistently use io error handlers
• miri: fix error returned from readdir_r when isolation is enabled, and uses of raw_os_error
• miri: implement LLVM x86 vpclmulqdq intrinsics
• miri: indicate more explicitly where we close host file/dir handles
• (Big performance change) Do not run lints that cannot emit
• optimize Rc<T>::default
• specialize read_exact and read_buf_exact for VecDeque
• stabilize isqrt feature
• stabilize shorter-tail-lifetimes
• support char::is_digit in const contexts
• remove the Arc rt::init allocation for thread info
• provide a default impl for Pattern::as_utf8_pattern
• vectorized SliceContains
• avoid using imports in thread_local_inner! in static
• better default capacity for str::replace
• musl: use posix_spawn if a directory change was requested
• cargo resolver: Make room for v3 resolver
• cargo complete: Include descriptions in zsh
• cargo env: remove unnecessary clones
• cargo: fingerprint: avoid unnecessary fopen calls
• cargo: added unstable-schema generation for Cargo.toml
• cargo: deprecate cargo verify-project
• cargo fix: add source replacement info when no matching package found
• cargo fix: trace config [env] table in dep-info
• cargo test: add fixes in the sat resolver
• rustdoc: Do not consider nested functions as main function even if named main in doctests
• rustdoc: extend fake_variadic to "wrapped" tuples
• rustdoc: hash assets at rustdoc build time
• allow type-based search on foreign functions
• clippy: borrow_deref_ref: do not trigger on &raw references
• clippy: don't trigger const_is_empty for inline const assertions
• clippy: fire large_const_arrays for computed array lengths
• clippy: fix incorrect suggestion for !(a >= b) as i32 == c
• clippy: fix not working lint anchor (generation and filtering)
• clippy: remove unnecessary filter_map usages
• clippy: stop linting unused_io_amount in io traits
• rust-analyzer: add text edits to more inlay hints
• rust-analyzer: implement diagnostics pull model
• rust-analyzer: render docs from aliased type when type has no docs
• rust-analyzer: resolve range patterns to their structs
• rust-analyzer: split macro-error diagnostic so users can ignore only parts of it
• rust-analyzer: support cfg(true) and cfg(false)
• rust-analyzer: fix diagnostic enable config being ignored
• rust-analyzer: fix dyn incompatible hint message
• rust-analyzer: fix formatting on welcome page, read only paths setting example
• rust-analyzer: add missing cfg flags for core crate
• rust-analyzer: allow public re-export of extern crate import
• rust-analyzer: correctly handle #"" in edition <2024
• rust-analyzer: don't compute diagnostics for non local files
• rust-analyzer: fix checking for false labelDetailsSupport value
• rust-analyzer: fix incorrect parsing of use bounds
• rust-analyzer: handle missing time offsets gracefully
• rust-analyzer: implement mixed site hygiene
• rust-analyzer: nail destructuring assignment once and for all
• rust-analyzer: prevent public re-export of private item
• rust-analyzer: properly resolve prelude paths inside modules inside blocks
• rust-analyzer: put leading | in patterns under OrPat
• rust-analyzer: turn "Remove dbg!" into a quick fix for better prioritization
• rust-analyzer: move text-edit into ide-db
• rust-analyzer: only construct a resolver in macro descension when needed
• rust-analyzer: swap query call order in file_item_tree_query

Rust Compiler Performance Triage

This week saw a lot of activity both on the regressions and improvements side. There was one large regression, which was immediately reverted. Overall, the week ended up being positive, thanks to a rollup PR that caused a tiny improvement to almost all benchmarks.

Triage done by @kobzol. Revision range: 3e33bda0..c8a8c820

Summary:

6 Regressions, 6 Improvements, 4 Mixed; 6 of them in rollups 58 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

Rust

• [disposition: merge] Decide whether blocks inside asm goto should default to safe
• [disposition: merge] #[inline(never)] does not work for async functions
• [disposition: not specified] Add LowerExp and UpperExp implementations to NonZero

Cargo

• No Cargo Tracking Issues or PRs entered Final Comment Period this week.

Language Team

• No Language Team Proposals entered Final Comment Period this week.

Language Reference

• No Language Reference RFCs entered Final Comment Period this week.

Unsafe Code Guidelines

• No Unsafe Code Guideline Tracking Issues or PRs entered Final Comment Period this week.

New and Updated RFCs

• [new] RFC: Labeled match
• [new] RFC: Never patterns
• [new] [RFC] Allow packed types to transitively contain aligned types
• [new] [RFC] Target Modifiers

Upcoming Events

Rusty Events between 2024-10-30 - 2024-11-27 🦀

Virtual

• 2024-10-31 | Virtual (Charlottesville, NC, US) | Charlottesville Rust Meetup
  • Crafting Interpreters in Rust Collaboratively
• 2024-10-31 | Virtual (Nürnberg, DE) | Rust Nurnberg DE
  • Rust Nürnberg online
• 2024-11-01 | Virtual (Jersey City, NJ, US) | Jersey City Classy and Curious Coders Club Cooperative
  • Rust Coding / Game Dev Fridays Open Mob Session!
• 2024-11-02 | Virtual( Kampala, UG) | Rust Circle Kampala
  • Rust Circle Meetup
• 2024-11-06 | Virtual (Indianapolis, IN, US) | Indy Rust
  • Indy.rs - with Social Distancing
• 2024-11-07 | Virtual (Berlin, DE) | OpenTechSchool Berlin + Rust Berlin
  • Rust Hack and Learn | Mirror: Rust Hack n Learn Meetup
• 2024-11-08 | Virtual (Jersey City, NJ, US) | Jersey City Classy and Curious Coders Club Cooperative
  • Rust Coding / Game Dev Fridays Open Mob Session!
• 2024-11-12 | Virtual (Dallas, TX, US) | Dallas Rust
  • Second Tuesday
• 2024-11-14 | Virtual (Charlottesville, NC, US) | Charlottesville Rust Meetup
  • Crafting Interpreters in Rust Collaboratively
• 2024-11-14 | Virtual and In-Person (Lehi, UT, US) | Utah Rust
  • Green Thumb: Building a Bluetooth-Enabled Plant Waterer with Rust and Microbit
• 2024-11-14 | Virtual and In-Person (Seattle, WA, US) | Seattle Rust User Group
  • November Meetup
• 2024-11-15 | Virtual (Jersey City, NJ, US) | Jersey City Classy and Curious Coders Club Cooperative
  • Rust Coding / Game Dev Fridays Open Mob Session!
• 2024-11-19 | Virtual (Los Angeles, CA, US) | DevTalk LA
  • Discussion - Topic: Rust for UI
• 2024-11-19 | Virtual (Washington, DC, US) | Rust DC
  • Mid-month Rustful
• 2024-11-20 | Virtual and In-Person (Vancouver, BC, CA) | Vancouver Rust
  • Embedded Rust Workshop
• 2024-11-21 | Virtual (Charlottesville, NC, US) | Charlottesville Rust Meetup
  • Trustworthy IoT with Rust--and passwords!
• 2024-11-21 | Virtual (Rotterdam, NL) | Bevy Game Development
  • Bevy Meetup #7
• 2024-11-26 | Virtual (Dallas, TX, US) | Dallas Rust
  • Last Tuesday

Europe

• 2024-10-30 | Hamburg, DE | Rust Meetup Hamburg
  • Rust Hack & Learn October 2024
• 2024-10-31 | Berlin, DE | OpenTechSchool Berlin + Rust Berlin
  • Rust and Tell - Title
• 2024-10-31 | Copenhagen, DK | Copenhagen Rust Community
  • Rust meetup #52 sponsored by Trifork and OpenZeppelin
• 2024-11-05 | Copenhagen, DK | Copenhagen Rust Community
  • Rust Hack Night #10: Rust <3 Nix
• 2024-11-06 | Oxford, UK | Oxford Rust Meetup Group
  • Oxford Rust and C++ social
• 2024-11-06 | Paris, FR | Paris Rustaceans
  • Rust Meetup in Paris
• 2024-11-12 | Zurich, CH | Rust Zurich
  • Encrypted/distributed filesystems, wasm-bindgen
• 2024-11-13 | Reading, UK | Reading Rust Workshop
  • Reading Rust Meetup
• 2024-11-14 | Stockholm, SE | Stockholm Rust
  • Rust Meetup @UXStream
• 2024-11-19 | Leipzig, DE | Rust - Modern Systems Programming in Leipzig
  • Daten sichern mit ZFS (und Rust)
• 2024-11-21 | Edinburgh, UK | Rust and Friends
  • Rust and Friends (pub)
• 2024-11-21 | Oslo, NO | Rust Oslo
  • Rust Hack'n'Learn at Kampen Bistro
• 2024-11-23 | Basel, CH | Rust Basel
  • Rust + HTMX - Workshop #3

North America

• 2024-10-30 | Chicago, IL, US | Deep Dish Rust
  • Rust Workshop: deploying your code
• 2024-10-31 | Mountain View, CA, US | Mountain View Rust Meetup
  • Rust Meetup at Hacker Dojo
• 2024-11-04 | Brookline, MA, US | Boston Rust Meetup
  • Coolidge Corner Brookline Rust Lunch, Nov 4
• 2024-11-07 | Montréal, QC, CA | Rust Montréal
  • November Monthly Social
• 2024-11-07 | St. Louis, MO, US | STL Rust
  • Game development with Rust and the Bevy engine
• 2024-11-12 | Ann Arbor, MI, US | Detroit Rust
  • Rust Community Meetup - Ann Arbor
• 2024-11-14 | Mountain View, CA, US | Hacker Dojo
  • Rust Meetup at Hacker Dojo
• 2024-11-15 | Mexico City, DF, MX | Rust MX
  • Multi threading y Async en Rust parte 2 - Smart Pointes y Closures
• 2024-11-15 | Somerville, MA, US | Boston Rust Meetup
  • Ball Square Rust Lunch, Nov 15
• 2024-11-19 | San Francisco, CA, US | San Francisco Rust Study Group
  • Rust Hacking in Person
• 2024-11-23 | Boston, MA, US | Boston Rust Meetup
  • Boston Common Rust Lunch, Nov 23
• 2024-11-25 | Ferndale, MI, US | Detroit Rust
  • Rust Community Meetup - Ferndale
• 2024-11-27 | Austin, TX, US | Rust ATX
  • Rust Lunch - Fareground

Oceania

• 2024-10-31 | Auckland, NZ | Rust AKL
  • Rust AKL: Rust on AWS: Sustainability + Peace: Zero Stress Automation
• 2024-11-12 | Christchurch, NZ | Christchurch Rust Meetup Group
  • Christchurch Rust Meetup

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

An earnest effort to pursue [P1179R1] as a Lifetime TS[P3465R0] will compromise on C++’s outdated and unworkable core principles and adopt mechanisms more like Rust’s. In the compiler business this is called carcinization: a tendency of non-crab organisms to evolve crab-like features. – Sean Baxter on circle-lang.org

Thanks to Collin Richards 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