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

• gccrs: An alternative compiler for Rust
• Google Summer of Code 2024 results

Foundation

• Rust Foundation Releases Problem Statement on C++/Rust Interoperability

Newsletters

• Linebender in October 2024: resvg stewardship
• The Embedded Rustacean Issue #32

Project/Tooling Updates

• Introducing Hyperlight: Virtual machine-based security for functions at scale
• Introducing Sled, a Rust Library for Creating Spatial LED Strip Lighting Effects
• Redis Shield: A high-performance rate limiting module in Rust using the Token Bucket algorithm
• Cohen: gccrs: An alternative compiler for Rust
• Progress on toolchain security features
• Next-gen builder macro Bon 3.0 release

Observations/Thoughts

• Perhaps Rust needs "defer"
• Rust needs an official specification
• Why is std::pin::Pin so weird?
• Bringing faster exceptions to Rust
• Exploring the Assembly Code generated by Rust Recursive Tree Traversal
• Typed IDs with SeaORM
• Spawning Processes in Linux
• [video] Rust 2024 Project Goals Update & Rust 1.80.1
• [video] Rio: Next generation terminal emulator written in Rust

Rust Walkthroughs

• Parsing arguments in Rust with no dependencies
• Using portable SIMD in stable Rust
• Rust Syn Crate Tutorial: Automate Builder Patterns with Custom Macros
• Tutorial: Implementing JSON parsing
• Impl Snake For Micro:bit - Embedded async Rust on BBC Micro:bit with Embassy

Miscellaneous

• October 2024 Rust Jobs Report

Crate of the Week

This week's crate is struct-split, a proc macro to implement partial borrows.

Thanks to Felix 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.

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 — multiple basic/bearer credentials for 'Authorization' server support
• [Rama — implement take and replace for Context and Extensions](https://github.com/plabayo/rama/issues/353

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

403 pull requests were merged in the last week

• remove the wasm32-wasi target from rustc
• add a new wide-arithmetic feature for WebAssembly
• add Unicode block-drawing compiler output support
• add {ignore,needs}-{rustc,std}-debug-assertions directive support
• add a default implementation for CodegenBackend::link
• add discriminators to DILocations when multiple functions are inlined into a single point
• add v9, v8plus, and leoncasa target feature to sparc and use v8plus in create_object_file
• additional tests to ensure let is rejected during parsing
• arbitrary self types v2: (unused) Receiver trait
• basic inline assembly support for SPARC and SPARC64
• coverage: extract safe FFI wrapper functions to llvm_cov
• coverage: restrict empty-span expansion to only cover { and }
• coverage: simplify parts of coverage graph creation
• do not filter empty lint passes & re-do CTFE pass
• do not reveal opaques in the param-env, we got lazy norm instead
• do not trust download-rustc=if-unchanged on CI for now
• don't suggest .into_iter() on iterators
• don't use maybe_unwrap_block when checking for macro calls in a block expr
• dont suggest use<impl Trait> when we have an edition-2024-related borrowck issue
• drop "gnu" in the target env for FreeBSD armv6/7
• emit warning when calling/declaring functions with unavailable vectors
• enforce that raw lifetimes must be valid raw identifiers
• ensure that tail expr receive lifetime extension
• fix parens mangled in shared mut static lint suggestion
• get rid of check_opaque_type_well_formed
• make RustString an extern type to avoid improper_ctypes warnings
• make Ty::primitive_symbol recognize str
• make fn_abi_sanity_check a bit stricter
• make sure that we suggest turbofishing the right type arg for never suggestion
• mark some target features as 'forbidden' so they cannot be (un)set with -Ctarget-feature
• only disable cache if predicate has opaques within it
• passWrapper: adapt for new parameter in LLVM
• prefer pub(super) in unreachable_pub lint suggestion
• properly suggest E::assoc when we encounter E::Variant::assoc
• provide placeholder generics for traits in "no method found for type parameter" suggestions
• reject raw lifetime followed by ', like regular lifetimes do
• remove 'platform-intrinsic' ABI leftovers
• remove rustc_session::config::rustc_short_optgroups
• remove support for rustc_safe_intrinsic attribute; use rustc_intrinsic functions instead
• remove unnecessary pub enum glob-imports from rustc_middle::ty
• require const_impl_trait gate for all conditional and trait const calls
• revert using HEAP static in Windows alloc
• set "symbol name" in raw-dylib import libraries to the decorated name
• simplify FFI calls for -Ztime-llvm-passes and -Zprint-codegen-stats
• simplify some places that deal with generic parameter defaults
• simplify the internal API for declaring command-line options
• suggest swapping LHS and RHS when RHS impls PartialEq<lhs_ty>
• tweak E0320 overflow error wording
• tweak detection of multiple crate versions to be more encompassing
• use download-rustc="if-unchanged" as a global default
• use a separate dir for r-a builds consistently in helix config
• use verbose for path separator suggestion
• pointee_info_at: fix logic for recursing into enums
• rustc_codegen_llvm: Add a new 'pc' option to branch-protection
• rustc_target: more target string fixes for LLVM 20
• interpret: get_alloc_info: also return mutability
• StableMIR: A few fixes to pretty printing
• StableMIR: API to retrieve definitions from crates
• miri: fix linux-futex test being accidentally disabled
• miri: get/set thread name shims return errors for invalid handles
• miri: preparing for merge from rustc
• miri: pthread-sync test: avoid confusing error when running with preemption
• miri: remove MutexID list
• miri: renamed this arguments to ecx
• miri: stacked borrows tests: add those that fail under TB
• miri: standardized variable names for InterpCx
• miri: store futexes in per-allocation data rather than globally
• miri: sync support: dont implicitly clone inside the general sync machinery
• stabilise const_char_encode_utf16
• stabilize Arm64EC inline assembly
• stabilize WebAssembly multivalue, reference-types, and tail-call target features
• stabilize UnsafeCell::from_mut
• stabilize s390x inline assembly
• add new unstable feature const_eq_ignore_ascii_case
• make char::is_whitespace unstably const
• inline str::repeat
• core/fmt: Replace checked slice indexing by unchecked to support panic-free code
• add Set entry API
• implement div_ceil for NonZero<unsigned>
• implement file_lock feature
• initialize channel Blocks directly on the heap
• disable f16 on platforms that have recursion problems
• cargo: warnings: add build.warnings option
• cargo: test: Make redactions consistent with snapbox
• cargo: git: do not validate submodules of fresh checkouts
• cargo: normalize the target paths
• cargo: refactor: clone-on-write when needed for InternedString
• cargo: rustfix: replace special-case duplicate handling with error
• rustdoc-search: show type signature on type-driven SERP
• rustdoc-search: simplify rules for generics and type params
• bindgen: fix field_visibility not called for new-type aliases
• bindgen: fix unsafe_op_in_unsafe_fn when using dynamic librarys and wrap_unsafe_ops
• handle separate prefixes in clippy rules
• clippy: no_mangle_with_rust_abi: properly position the suggested ABI
• clippy: add match-based manual try to clippy::question_mark
• clippy: collect attribute spans early for disallowed macros
• clippy: fix large_include_file lint being triggered all the time by doc comments
• clippy: fix: identity_op suggestions use correct parenthesis
• rust-analyzer: editors/code: change minimum VS Code from 1.78 to 1.83
• rust-analyzer: use completion item indices instead of property matching when searching for the completion item to resolve

Rust Compiler Performance Triage

Regressions primarily in doc builds. No significant changes in cycle or max-rss counts.

Triage done by @simulacrum. Revision range: 27e38f8f..d4822c2d

1 Regressions, 1 Improvements, 4 Mixed; 1 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:

• 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] [RFC] Thread spawn hook (inheriting thread locals)

Tracking Issues & PRs

Rust

• [disposition: merge] Tracking issue for const_size_of_val and const_align_of_val
• [disposition: merge] mark is_val_statically_known intrinsic as stably const-callable
• [disposition: merge] Tracking issue for const <*const T>::is_null
• [disposition: merge] Tracking issue for const Pin methods
• [disposition: merge] Stabilize const_atomic_from_ptr

Cargo

• [disposition: merge] feat(resolver): Stabilize resolver v3

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: Unsafe Set Enum Discriminants

Upcoming Events

Rusty Events between 2024-11-13 - 2024-12-11 🦀

Virtual

• 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 (Cardiff, UK) | Rust and C++ Cardiff
  • Rust for Rustaceans Book Club: Chapter 12: Rust Without the Standard Library
• 2024-11-20 | Virtual and In-Person (Vancouver, BC, CA) | Vancouver Rust
  • Embedded Rust Workshop
• 2024-11-21 | Virtual (Berlin, DE) | OpenTechSchool Berlin + Rust Berlin
  • Rust Hack and Learn | Mirror: Rust Hack n Learn Meetup
• 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
• 2024-11-25 | Virtual (Bratislava, SK) | Bratislava Rust Meetup Group
  • ONLINE Talk, sponsored by Sonalake - Bratislava Rust Meetup
• 2024-11-26 | Virtual (Dallas, TX, US) | Dallas Rust
  • Last Tuesday
• 2024-11-28 | Virtual (Charlottesville, NC, US) | Charlottesville Rust Meetup
  • Crafting Interpreters in Rust Collaboratively
• 2024-11-28 | Virtual (Nürnberg, DE) | Rust Nuremberg
  • Rust Nürnberg online
• 2024-12-03 | Virtual (Buffalo, NY, US) | Buffalo Rust Meetup
  • Buffalo Rust User Group
• 2024-12-04 | Virtual (Indianapolis, IN, US) | Indy Rust
  • Indy.rs - with Social Distancing
• 2024-12-05 | Virtual (Berlin, DE) | OpenTechSchool Berlin + Rust Berlin
  • Rust Hack and Learn | Mirror: Rust Hack n Learn Meetup
• 2024-12-10 | Virtual (Dallas, TX, US) | Dallas Rust
  • Second Tuesday
• 2024-12-11 | Virtual (Vancouver, BC, CA) | Vancouver Rust
  • Rust Study/Hack/Hang-out

Africa

• 2024-12-07 | Virtual( Kampala, UG) | Rust Circle Kampala
  • Rust Circle Meetup

Asia

• 2024-11-28 | Bangalore/Bengaluru, IN | Rust Bangalore
  • RustTechX Summit 2024 BOSCH
• 2024-11-30 | Tokyo, JP | Rust Tokyo
  • Rust.Tokyo 2024

Europe

• 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)
• 2024-11-19 | Paris, FR | Rust Paris
  • Rust meetup #72
• 2024-11-21 | Edinburgh, UK | Rust and Friends
  • Rust and Friends (pub)
• 2024-11-21 | Madrid, ES | MadRust
  • Taller de introducción a unit testing en Rust
• 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
• 2024-11-26 | Warsaw, PL | Rust Warsaw
  • New Rust Warsaw Meetup #3
• 2024-11-27 | Dortmund, DE | Rust Dortmund
  • Rust Dortmund
• 2024-11-28 | Aarhus, DK | Rust Aarhus
  • Talk Night at Lind Capital
• 2024-11-28 | Augsburg, DE | Rust Meetup Augsburg
  • Augsburg Rust Meetup #10
• 2024-11-28 | Berlin, DE | OpenTechSchool Berlin + Rust Berlin
  • Rust and Tell - Title
• 2024-11-28 | Gdansk, PL | Rust Gdansk
  • Rust Gdansk Meetup #5
• 2024-11-28 | Hamburg, DE | Rust Meetup Hamburg
  • Rust Hack & Learn with Mainmatter & Otto
• 2024-11-28 | Prague, CZ | Rust Prague
  • Rust/C++ Meetup Prague (November 2024)
• 2024-12-03 | Copenhagen, DK | Copenhagen Rust Community
  • Rust Hack Night #11: Advent of Code
• 2024-12-04 | Oxford, UK | Oxford Rust Meetup Group
  • Oxford Rust and C++ social
• 2024-12-05 | Olomouc, CZ | Rust Moravia
  • Rust Moravia Meetup (December 2024)
• 2024-12-06 | Moscow, RU | RustCon RU
  • RustCon Russia
• 2024-12-11 | Reading, UK | Reading Rust Workshop
  • Reading Rust Meetup

North America

• 2024-11-14 | Mountain View, CA, US | Hacker Dojo
  • Rust Meetup at Hacker Dojo
• 2024-11-14 | Portland, OR, US | PDXRust
  • PDXRust November 2024: Lightning Talks!
• 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
• 2024-11-19 | Spokane, WA, US | Spokane Rust
  • Building Your First Command Line Interface - A Code-Along Workshop
• 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
• 2024-11-26 | Minneapolis, MN, US | Minneapolis Rust Meetup
  • Minneapolis Rust Meetup Happy Hour
• 2024-11-27 | Austin, TX, US | Rust ATX
  • Rust Lunch - Fareground
• 2024-11-28 | Mountain View, CA, US | Hacker Dojo
  • RUST MEETUP at HACKER DOJO
• 2024-12-05 | St. Louis, MO, US | STL Rust
  • Rust Strings
• 2024-12-10 | Ann Arbor, MI, US | Detroit Rust
  • Rust Community Meetup - Ann Arbor

Oceania

• 2024-12-08 | Canberra, AU | Canberra Rust User Group
  • CRUG Xmas party

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

Netstack3 encompasses 63 crates and 60 developer-years of code. It contains more code than the top ten crates on crates.io combined. ... For the past eleven months, they have been running the new networking stack on 60 devices, full time. In that time, Liebow-Feeser said, most code would have been expected to show "mountains of bugs". Netstack3 had only three; he attributed that low number to the team's approach of encoding as many important invariants in the type system as possible.

– Joshua Liebow-Feeser at RustConf, as reported by Daroc Alden on Linux Weekly News

Thanks to Anton Fetisov 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