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.

Updates from Rust Community

Foundation

• Welcoming Rust-C++ Interoperability Engineer Jon Bauman to the Rust Foundation Team

RustNL 2024

• Visual Application Design for Rust - Rik Arends
• ThRust in Space: Initial Momentum - Michaël Melchiore
• Arc in the Linux Kernel - Alice Ryhl
• Making Connections - Mara Bos
• Replacing OpenSSL One Step at a Time - Joe Birr-Pixton
• Fortifying Rust's FFI with Enscapsulated Functions - Leon Schuermann
• Oxidizing Education - Henk Oordt
• Postcard: An Unreasonably Effective Tool for Machine to Machine Communication - James Munns
• Introducing June - Sophia Turner
• Robius: Immersive and Seamless Multiplatform App Development in Rust - Kevin Boos
• Compression Carcinized: Implementing zlib in Rust - Folkert de Vries
• K23: A Secure Research OS Running WASM - Jonas Kruckenberg
• Async Rust in Embedded Systems with Embassy - Dario Nieuwenhuis
• Xilem: Let's Build High Performance Rust UI - Raph Levien
• Rust Poisoning My Wrist for Fun - Ulf Lilleengen
• Type Theory for Busy Engineers - Niko Matsakis

Newsletters

• This Month in Rust GameDev #51 - May 2024

Project/Tooling Updates

• Enter paradis — A new chapter in Rust's parallelism story
• Tiny Glade, VJ performances, and 2d lighting
• Diesel 2.2.0
• Pigg 0.1.0
• git-cliff 2.3.0 is released! (highly customizable changelog generator)

Observations/Thoughts

• The borrow checker within
• Don't Worry About Lifetimes
• rust is not about memory safety
• On Dependency Usage in Rust
• Context Managers: Undroppable Types for Free
• Rust and dynamically-sized thin pointers
• Rust is for the Engine, Not the Game
• [audio] Thunderbird - Brendan Abolivier, Software Engineer

Rust Walkthroughs

• Build with Naz : Rust typestate pattern
• How to build a plugin system in Rust
• Forming Clouds
• Rust error handling: Option & Result
• Let's build a Load Balancer in Rust - Part 3
• The Ultimate Guide to Rust Newtypes

Miscellaneous

• Highlights from "I spent 6 years developing a puzzle game in Rust and it just shipped, AMA"

Crate of the Week

This week's crate is layoutparser-ort, a simplified port of LayoutParser for ML-based document layout element detection.

Despite there being no suggestions, llogiq is reasonably happy with his choice. Are you?

No matter what your answer is, 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.

No Calls for participation in projects were submitted this week.

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.

• Scientific Computing in Rust 2024 | Closes 2024-06-14 | online | Event date: 2024-07-17 - 2024-07-19
• Rust Ukraine 2024 | Closes 2024-07-06 | Online + Ukraine, Kyiv | Event date: 2024-07-27
• Conf42 Rustlang 2024 | Closes 2024-07-22 | online | Event date: 2024-08-22

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

308 pull requests were merged in the last week

• -Znext-solver: eagerly normalize when adding goals
• fn_arg_sanity_check: fix panic message
• add --print=check-cfg to get the expected configs
• add -Zfixed-x18
• also InstSimplify &raw*
• also resolve the type of constants, even if we already turned it into an error constant
• avoid unwrap diag.code directly in note_and_explain_type_err
• check index value <= 0xFFFF_FF00
• coverage: avoid overflow when the MC/DC condition limit is exceeded
• coverage: optionally instrument the RHS of lazy logical operators
• coverage: rename MC/DC conditions_num to num_conditions
• create const block DefIds in typeck instead of ast lowering
• do not equate Const's ty in super_combine_const
• do not suggest unresolvable builder methods
• a small diagnostic improvement for dropping_copy_types
• don't recompute tail in lower_stmts
• don't suggest turning non-char-literal exprs of ty char into string literals
• enable DestinationPropagation by default
• fold item bounds before proving them in check_type_bounds in new solver
• implement needs_async_drop in rustc and optimize async drop glue
• improve diagnostic output of non_local_definitions lint
• make ProofTreeBuilder actually generic over Interner
• make body_owned_by return the Body instead of just the BodyId
• make repr(packed) vectors work with SIMD intrinsics
• make lint: lint_dropping_references lint_forgetting_copy_types lint_forgetting_references give suggestion if possible
• omit non-needs_drop drop_in_place in vtables
• opt-in to FulfillmentError generation to avoid doing extra work in the new solver
• reintroduce name resolution check for trying to access locals from an inline const
• reject CVarArgs in parse_ty_for_where_clause
• show files produced by --emit foo in json artifact notifications
• silence some resolve errors when there have been glob import errors
• stop using translate_args in the new solver
• support mdBook preprocessors for TRPL in rustbook
• test codegen for repr(packed,simd) → repr(simd)
• tweak relations to no longer rely on TypeTrace
• unroll first iteration of checked_ilog loop
• uplift {Closure,Coroutine,CoroutineClosure}Args and friends to rustc_type_ir
• use parenthetical notation for Fn traits
• add some more specific checks to the MIR validator
• miri: avoid making a full copy of all new allocations
• miri: fix "local crate" detection
• don't inhibit random field reordering on repr(packed(1))
• avoid checking the edition as much as possible
• increase vtable layout size
• stabilise IpvNAddr::{BITS, to_bits, from_bits} (ip_bits)
• stabilize custom_code_classes_in_docs feature
• stablize const_binary_heap_constructor
• make std::env::{set_var, remove_var} unsafe in edition 2024
• implement feature integer_sign_cast
• NVPTX: avoid PassMode::Direct for args in C abi
• genericize ptr::from_raw_parts
• std::pal::unix::thread fetching min stack size on netbsd
• add an intrinsic for ptr::metadata
• change f32::midpoint to upcast to f64
• rustc-hash: replace hash with faster and better finalized hash
• cargo test: Auto-redact elapsed time
• cargo add: Avoid escaping double-quotes by using string literals
• cargo config: Ensure --config net.git-fetch-with-cli=true is respected
• cargo new: Dont say were adding to a workspace when a regular package is in root
• cargo toml: Ensure targets are in a deterministic order
• cargo vendor: Ensure sort happens for vendor
• cargo: allows the default git/gitoxide configuration to be obtained from the ENV and config
• cargo: adjust custom err from cert-check due to libgit2 1.8 change
• cargo: skip deserialization of unrelated fields with overlapping name
• clippy: many_single_char_names: deduplicate diagnostics
• clippy: add needless_character_iteration lint
• clippy: deprecate maybe_misused_cfg and mismatched_target_os
• clippy: disable indexing_slicing for custom Index impls
• clippy: fix redundant_closure suggesting incorrect code with F: Fn()
• clippy: let non_canonical_impls skip proc marco
• clippy: ignore array from deref_addrof lint
• clippy: make str_to_string machine-applicable
• rust-analyzer: add Function::fn_ptr_type(…) for obtaining name-erased function type
• rust-analyzer: don't mark #[rustc_deprecated_safe_2024] functions as unsafe
• rust-analyzer: enable completions within derive helper attributes
• rust-analyzer: fix container search failing for tokens originating within derive attributes
• rust-analyzer: fix diagnostics clearing when flychecks run per-workspace
• rust-analyzer: only generate snippets for extract_expressions_from_format_string if snippets are supported
• rustfmt: collapse nested if detected by clippy
• rustfmt: rustfmt should not remove inner attributes from inline const blocks
• rustfmt: rust rewrite check_diff (Skeleton)
• rustfmt: use with_capacity in rewrite_path

Rust Compiler Performance Triage

A quiet week; we did have one quite serious regression (#115105, "enable DestinationPropagation by default"), but it was shortly reverted (#125794). The only other PR identified as potentially problematic was rollup PR #125824, but even that is relatively limited in its effect.

Triage done by @pnkfelix. Revision range: a59072ec..1d52972d

3 Regressions, 5 Improvements, 6 Mixed; 4 of them in rollups 57 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

• Change crates.io policy to not offer crate transfer mediation

Tracking Issues & PRs

Rust

• [disposition: merge] Allow constraining opaque types during subtyping in the trait system
• [disposition: merge] TAIT decision on "may define implies must define"
• [disposition: merge] Stabilize Wasm relaxed SIMD

Cargo

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

Language Team

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

New and Updated RFCs

• No New or Updated RFCs were created this week.

Upcoming Events

Rusty Events between 2024-06-05 - 2024-07-03 🦀

Virtual

• 2024-06-05 | Virtual (Indianapolis, IN, US) | Indy Rust
  • Indy.rs - with Social Distancing
• 2024-06-06 | Virtual (Tel Aviv, IL) | Code Mavens
  • Rust Maven Workshop: Your first contribution to an Open Source Rust project
• 2024-06-06 | Virtual (Berlin, DE) | OpenTechSchool Berlin + Rust Berlin
  • Rust Hack and Learn | Mirror: Rust Hack n Learn Meetup
• 2024-06-09 | Virtual (Tel Aviv, IL) | Code Mavens
  • Rust Maven Workshop: GitHub pages for Rust developers (English)
• 2024-06-11 | Virtual (Dallas, TX, US) | Dallas Rust
  • Second Tuesday
• 2024-06-12 | Virtual (Cardiff, UK)| Rust and C++ Cardiff
  • Rust for Rustaceans Book Club: Chapter 8 - Asynchronous Programming
• 2024-06-13 | Virtual (Charlottesville, NC, US) | Charlottesville Rust Meetup
  • Crafting Interpreters in Rust Collaboratively
• 2024-06-13 | Virtual (Nürnberg, DE) | Rust Nuremberg
  • Rust Nürnberg online
• 2024-06-16 | Virtual (Tel Aviv, IL) | Code Mavens
  • Workshop: Web development in Rust using Rocket (English)
• 2024-06-18 | Virtual (Washington, DC, US) | Rust DC
  • Mid-month Rustful
• 2024-06-19 | Virtual (Vancouver, BC, CA) | Vancouver Rust
  • Rust Study/Hack/Hang-out
• 2024-06-20 | Virtual (Berlin, DE) | OpenTechSchool Berlin + Rust Berlin
  • Rust Hack and Learn | Mirror: Rust Hack n Learn Meetup
• 2024-06-25 | Virtual (Dallas, TX, US)| Dallas Rust User Group
  • Last Tuesday
• 2024-06-27 | Virtual (Charlottesville, NC, US) | Charlottesville Rust Meetup
  • Crafting Interpreters in Rust Collaboratively
• 2024-07-02 | Virtual (Buffalo, NY) | Buffalo Rust Meetup
  • Buffalo Rust User Group
• 2024-07-03 | Virtual | Training 4 Programmers LLC
  • Build Web Apps with Rust and Leptos
• 2024-07-03 | Virtual (Indianapolis, IN, US) | Indy Rust
  • Indy.rs - with Social Distancing

Europe

• 2024-06-05 | Hamburg, DE | Rust Meetup Hamburg
  • Rust Hack & Learn June 2024
• 2024-06-06 | Madrid, ES | MadRust
  • Introducción a Rust y el futuro de los sistemas DLT
• 2024-06-06 | Vilnius, LT | Rust Vilnius
  • Enjoy our second Rust and ZIG event
• 2024-06-06 | Wrocław, PL | Rust Wroclaw
  • Rust Meetup #37
• 2024-06-11 | Copenhagen, DK | Copenhagen Rust Community
  • Rust Hack Night #6: Discord bots
• 2024-06-11 | Paris, FR | Rust Paris
  • Paris Rust Meetup #69
• 2024-06-12 | Reading, UK | Reading Rust Workshop
  • Reading Rust Meetup
• 2024-06-18 | Frankfurt/Main, DE | Rust Frankfurt Meetup
  • Rust Frankfurt is Back!
• 2024-06-19 - 2024-06-24 | Zürich, CH | RustFest Zürich
  • RustFest Zürich 2024
• 2024-06-20 | Aarhus, DK | Rust Aarhus
  • Talk Night at Trifork
• 2024-06-25 | Gdańsk, PL | Rust Gdansk
  • Rust Gdansk Meetup #3
• 2024-06-27 | Berlin, DE | Rust Berlin
  • Rust and Tell - Title
• 2024-06-27 | Copenhagen, DK | Copenhagen Rust Community
  • Rust meetup #48 sponsored by Google!

North America

• 2024-06-08 | Somerville, MA, US | Boston Rust Meetup
  • Porter Square Rust Lunch, Jun 8
• 2024-06-11 | New York, NY, US | Rust NYC
  • Rust NYC Monthly Meetup
• 2024-06-12 | Detroit, MI, US | Detroit Rust
  • Detroit Rust Meet - Ann Arbor
• 2024-06-13 | Spokane, WA, US | Spokane Rust
  • Monthly Meetup: Topic TBD!
• 2024-06-17 | Minneapolis, MN US | Minneapolis Rust Meetup
  • Minneapolis Rust Meetup Happy Hour
• 2024-06-18 | San Francisco, CA, US | San Francisco Rust Study Group
  • Rust Hacking in Person
• 2024-06-20 | Seattle, WA, US | Seattle Rust User Group
  • Seattle Rust User Group Meetup
• 2024-06-26 | Austin, TX, US | Rust ATC
  • Rust Lunch - Fareground
• 2024-06-27 | Nashville, TN, US | Music City Rust Developers
  • Music City Rust Developers: Holding Pattern

Oceania

• 2024-06-14 | Melbourne, VIC, AU | Rust Melbourne
  • June 2024 Rust Melbourne Meetup
• 2024-06-20 | Auckland, NZ | Rust AKL
  • Rust AKL: Full Stack Rust + Writing a compiler for fun and (no) profit
• 2024-06-25 | Canberra, ACt, AU | Canberra Rust User Group (CRUG)
  • June Meetup

South America

• 2024-06-06 | Buenos Aires, AR | Rust en Español | Rust Argentina
  • Juntada de Junio

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

Every PR is Special™

– Hieyou Xu describing being on t-compiler review rotation

Sadly, there was no suggestion, so llogiq came up with something hopefully suitable.

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