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

Official

• Announcing Rust 1.82.0

Project/Tooling Updates

• Ratatui 0.29.0
• Life of a Zed Extension: Rust, WIT, Wasm
• Shuttle’s New Platform — Redefining Backend Development
• Hifitime version 4.0.0: A Leap Forward in Time Management
• Fjall 2.2 - now supports serializable snapshot isolation (multi-writer transactions)
• pg-extras-rs - PostgreSQL database performance insights

Observations/Thoughts

• Rust's design goals should be about code
• UnpinCell
• Blocking code is a leaky abstraction
• Life as a Rust Project Contributor
• Rustls Outperforms OpenSSL and BoringSSL
• Using libgdx texture atlases in Bevy
• [audio] Rust in Production - Zed with Conrad Irwin
• [audio] Async Allocators
• [audio] PubNub with Stephen Blum

Rust Walkthroughs

• Demystifying Alignment and Memory Layout in Rust
• Using Rust in Non-Rust Servers to Improve Performance
• Async Rust in Three Parts
• When should I use String vs &str?
• Using Web Workers in Rust Webapps

Miscellaneous

• Starting a Rust Community

Crate of the Week

This week's crate is trait-gen, an attribute macro to generate the trait implementations for several types without needing custom declarative macros, code repetition, or blanket implementations.

Thanks to Luke Peterson for the 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.

Crates Ecosystem

• Request for input: zerocopy: Do you need IntoBytes support on unions? Please weigh in.

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.

• Rama — add "Deny All" Dns Resolver
• Rama — expand support to hijack based on context data
• Rama — support vec/array impl for DnsResolver
• Rama — Support IP modes in connector and resolver

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.

No Calls for papers or presentations were submitted this week.

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

464 pull requests were merged in the last week

• make rustc_abi compile on stable again
• optimize attribute applied to things other than methods/functions/c…
• rust_for_linux: -Zregparm=<N> commandline flag for X86
• rustc_llvm: Fix flattened CLI args
• add &pin (mut|const) T type position sugar
• add getentropy for RTEMS
• added more scenarios where comma to be removed in the function arg
• allow #[deny] inside #[forbid] as a no-op
• allow dropping dyn principal
• always specify llvm_abiname for RISC-V targets
• autodiff Upstreaming - enzyme frontend
• change orphan hint from "only" to "any uncovered type inside..."
• check for filecheck directives in files marked skip-filecheck
• compiler: adopt rust-analyzer impls for LayoutCalculatorError
• compiler: error on layout of enums with invalid reprs
• compiler: use LLVM's Comdat support
• continue to get rid of ty::Const::{try_}eval*
• coverage: make counter creation handle node/edge counters more uniformly
• default to the medium code model on OpenHarmony LoongArch target
• delay ambiguous intra-doc link resolution after Cache has been populated
• do not run test where it cannot run
• don't check unsize goal in MIR validation when opaques remain
• don't report on_unimplemented message for negative traits
• don't report bivariance error when nesting a struct with field errors into another struct
• dont ICE when computing coverage of synthetic async closure body
• dont consider predicates that may hold as impossible in is_impossible_associated_item
• enable XRay instrumentation for LoongArch Linux targets
• fix coherence error for very large tuples™
• fix range misleading field access
• handle gracefully true/false in cfg(target(..)) compact
• implement edition 2024 match ergonomics restrictions
• make unsupported_calling_conventions a hard error
• make destructors on extern "C" frames to be executed
• make some float methods unstable const fn
• make sure that outer opaques capture inner opaques's lifetimes even with precise capturing syntax
• never emit vptr for empty/auto traits
• register src/tools/unicode-table-generator as a runnable tool
• remove invalid help diagnostics for const pointer
• return values larger than 2 registers using a return area pointer
• setting up indirect access to external data for loongarch64-linux-{musl,ohos}
• try to improve error messages involving aliases in the solver
• warn less about non-exhaustive in ffi
• miri: epoll_ctl: throw unsupported error on unsupported opcode
• miri: android: added support for prctl handling thread names
• miri: improve support for f16 and f128
• add fast-path when computing the default visibility
• use ThinVec for PredicateObligation storage
• finish stabilization of result_ffi_guarantees
• stabilize Strict Provenance and Exposed Provenance APIs
• stabilize -Znext-solver=coherence again
• add from_ref and from_mut constructors to core::ptr::NonNull
• add must_use to CommandExt::exec
• avoid use imports in thread_local_inner!
• mark the unstable LazyCell::into_inner const
• optimize Box::default and Arc::default to construct more types in place
• optimize str.replace
• partially stabilize const_pin
• refactor some core::fmt macros
• avoid superfluous UB checks in IndexRange
• relax a memory order in once_box
• speedup directory traversal on windows
• std: uefi: add basic Env variables
• uefi: implement getcwd and chdir
• cargo: registry: HttpRegistry block_until_ready returns early when work is still pending
• cargo: resolver: avoid cloning when iterating using RcVecIter
• cargo: stabilize MSRV-aware resolver config
• rustdoc-json-types: introduce rustc-hash feature
• rustdoc-json-types: mark simple enums as copy
• rustdoc: switch from FxHash to sha256 for static file hashing
• rustfmt for<'a> async correctly
• rustfmt: compile_rustfmt rewrite
• rustfmt: apply 2024 version sort algorithm to mods
• rustfmt: defer changes for zero argument functions until style_edition=2027
• clippy: add lint for unnecessary lifetime bounded &str return
• clippy: allow to go through clippy lints page without javascript
• clippy: change the category of manual_is_power_of_two to pedantic
• clippy: stop linting manual_bits in any macro invocation
• rust-analyzer: add wrap/unwrap return type in Option
• rust-analyzer: clamp Position::character to line length
• rust-analyzer: do not consider match/let/ref of place that evaluates to ! to diverge, disallow coercions from them too
• rust-analyzer: better completions for extern blocks
• rust-analyzer: goto definition on range operators
• rust-analyzer: initial support for safe_kw in extern blocks
• rust-analyzer: support initializeStopped setting
• rust-analyzer: fix status bar message not being marked markdown
• rust-analyzer: classify safe as a contextual keyword
• rust-analyzer: fix token downmapping failing for include! inputs
• rust-analyzer: private items are shown in completions for modules in fn body

Rust Compiler Performance Triage

Some tidy improvements from switching to next generation trait solver (solely for coherence checking) and from simplifying our dataflow analysis framework. There were some binary size regressions associated with PR 126557 (adding #[track_caller] to allocating methods of Vec and VecDeque), which I have handed off to T-libs to choose whether to investigate further.

Triage done by @pnkfelix. Revision range: 5ceb623a..3e33bda0

0 Regressions, 3 Improvements, 6 Mixed; 3 of them in rollups 47 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:

• RFC: Allow boolean literals as cfg predicates

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] RFC: Give users control over feature unification
• [disposition: merge] [RFC] Default field values
• [disposition: merge] Trait method impl restrictions

Tracking Issues & PRs

Rust

• [disposition: merge] Add lint against function pointer comparisons
• [disposition: merge] Implement From<&mut {slice}>1 for Box/Rc/Arc<{slice}>
• [disposition: merge] Tracking Issue for const_arguments_as_str
• [disposition: not specified] Add LowerExp and UpperExp implementations to NonZero
• [disposition: merge] Stabilize Ipv6Addr::is_unique_local and Ipv6Addr::is_unicast_link_local
• [disposition: merge] Make std::os::darwin public
• [disposition: merge] Tracking Issue for const_char_encode_utf16
• [disposition: merge] float types: move copysign, abs, signum to libcore
• [disposition: merge] Tracking Issue for {u8,i8,...}::isqrt
• [disposition: merge] Add --print host-triple to print host target triple
• [disposition: merge] Lint against &T to &mut T and &T to &UnsafeCell<T> transmutes
• [disposition: merge] Lint against getting pointers from immediately dropped temporaries
• [disposition: close] Consider deprecation of UB-happy static mut

Cargo

Language Team

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

Language Reference

• [disposition: unspecified] distinct 'static' items never overlap

Unsafe Code Guidelines

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

New and Updated RFCs

• [new] Unsafe derives and attributes
• [new] Macro fragment fields
• [new] Relaxed DST field ordering

Upcoming Events

Rusty Events between 2024-10-23 - 2024-11-20 🦀

Virtual

• 2024-10-24 | Virtual | Women in Rust
  • Part 4 of 4 - Hackathon Showcase: Final Projects and Presentations
• 2024-10-24 | Virtual (Berlin, DE) | OpenTechSchool Berlin + Rust Berlin
  • Rust Hack and Learn | Mirror: Rust Hack n Learn Meetup
• 2024-10-25 | Virtual (Jersey City, NJ, US) | Jersey City Classy and Curious Coders Club Cooperative
  • Rust Coding / Game Dev Fridays Open Mob Session!
• 2024-10-26 | Virtual (Gdansk, PL) | Stacja IT Trójmiasto
  • Rust – budowanie narzędzi działających w linii komend
• 2024-10-29 | Virtual (Dallas, TX, US) | Dallas Rust
  • Last Tuesday
• 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 (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

Asia

• 2024-10-29 | Tokyo, JP | Tokyo Rust Meetup
  • Bug-Free Concurrency in Rust

Europe

• 2024-10-26 | Stockholm, SE | Stockholm Rust
  • Ferris' Fika Forum #6
• 2024-10-28 | Paris, FR | Rust Paris
  • Rust Meetup #71
• 2024-10-29 | Aarhus, DK | Rust Aarhus
  • Hack Night
• 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
• 2024-11-06 | Oxford, UK | Oxford Rust Meetup Group
  • Oxford Rust and C++ social
• 2024-11-06 | Paris, FR | Paris Rustaceans
  • Rust Meetup in Paris
• 2024-11-14 | Stockholm, SE | Stockholm Rust
  • Rust Meetup @UXStream
• 2024-11-19 | Leipzig, DE | Rust - Modern Systems Programming in Leipzig
  • Daten sichern mit ZFS (und Rust)

North America

• 2024-10-23 | Austin, TX, US | Rust ATX
  • Rust Lunch - Fareground
• 2024-10-26 | Newark, NJ, US | NJ Code & Coffee
  • Intro to Rust: Build a Text Adventure Game x NJ Code & Coffee
• 2024-10-27 | Cambridge, MA, US | Boston Rust Meetup
  • Kendall Rust Lunch, Oct 27
• 2024-10-28 | Boulder, CO, US | Boulder Rust Meetup
  • Generics from the Ground Up
• 2024-10-28 | Ferndale, MI, US | Detroit Rust
  • Rust Community Meetup - Ferndale
• 2024-10-28 | Minneapolis, MN US | Minneapolis Rust Meetup
  • Minneapolis Rust Meetup Happy Hour
• 2024-10-29 | Nashville, TN, US | Music City Rust Developers
  • Music City Rust Developers : State of the Group and Expectations for 2025
• 2024-10-30 | Chicago, IL, US | Deep Dish Rust
  • Rust Workshop: deploying your code
• 2024-11-04 | Brookline, MA, US | Boston Rust Meetup
  • Coolidge Corner Brookline Rust Lunch, Nov 4
• 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
• 2024-11-15 | 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

Oceania

• 2024-10-28 | Melbourne, VIC, AU | Rust Melbourne
  • October 2024 Rust Melbourne Meetup
• 2024-10-29 | Canberra, ACT, AU | Canberra Rust User Group (CRUG)
  • June Meetup
• 2024-10-31 | Auckland, NZ | Rust AKL
  • Rust AKL: Rust on AWS: Sustainability + Peace: Zero Stress Automation

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

Your problem is that you’re trying to borrow from the dead.

– /u/masklinn on /r/rust

Thanks to Maciej Dziardziel 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