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

Newsletters

• ThisWeekInBevy: Bevy0.14-rc.2, Powerglove, and Soup
• This Month in Rust OSDev: May 2024

Project/Tooling Updates

• The Rust to .NET compiler (backend) can now properly compile the "guessing game" from the Rust book
• Cattaca 1.0.0
• BugStalker v0.2.0 - rust debugger

Observations/Thoughts

• How I spent 2 years building my own game engine (Rust, WASM, WebGPU)
• The Inconceivable Types of Rust: How to Make Self-Borrows Safe
• Making robots plan faster with SIMD and Rust
• Learning Rust: Bare Threading
• 999 crates of Rust on the wall
• How-to compile rust faster
• Tock binary size
• Virtual Geometry in Bevy 0.14
• Building Plain Old Data from Scratch
• Latency at the edge with Rust/WebAssembly and Postgres: Part 1, Part 2
• [video] Full-stack development of a B2B payment infrastructure with Rust - with Florent Bécart

Rust Walkthroughs

• [series] Master Hexagonal Architecture in Rust: Anatomy of a Bad Rust Application
• How to build a Custom Benchmarking Harness in Rust
• From Sender to Receiver: Rust’s Approach to Local File Transfers
• Build with Naz - Rust error handling with miette

Miscellaneous

• May 2024 Rust Jobs Report
• Virtual Rust Events

Crate of the Week

This week's crate is hydra, an actor framework inspired by Erlang/Elixir.

Thanks to DTZxPorter 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.

No Calls for participation 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

409 pull requests were merged in the last week

• fix: build on haiku
• unsafe extern blocks
• allow static mut definitions with #[linkage]
• closures are recursively reachable
• rustc_codegen_ssa: fix get_rpath_relative_to_output panic when lib only contains file name
• avoid follow-up errors if the number of generic parameters already doesn't match
• convert proc_macro_back_compat lint to an unconditional error
• detect pub structs never constructed and unused associated constants
• detect when user is trying to create a lending Iterator and give a custom explanation
• directly add extension instead of using Path::with_extension
• don't drop Unsize candidate in intercrate mode
• don't trigger unsafe_op_in_unsafe_fn for deprecated safe fns
• don't walk the bodies of free constants for reachability
• don't warn on fields in the unreachable_pub lint
• enable GVN for AggregateKind::RawPtr
• fix ICE caused by ignoring EffectVars in type inference
• fix ICE due to unwrap in probe_for_name_many
• improve renaming suggestion for names with leading underscores
• interpret: do not ICE on padded non-pow2 SIMD vectors
• make TLS accessors closures that return pointers
• make deleting on LinkedList aware of the allocator
• make html rendered by rustdoc allow searching non-English identifier / alias
• mark binding undetermined if target name exist and not obtained
• match ergonomics 2024: align implementation with RFC
• orphanck (old solver): Consider opaque types to never cover type parameters
• parse unsafe attributes
• raise DEFAULT_MIN_STACK_SIZE to at least 64KiB
• resolve: mark it undetermined if single import has no bindings
• scalarInt: size mismatches are a bug, do not delay the panic
• set has_unconstrained_ty_var when generalizing aliases in bivariant contexts
• silence follow-up errors directly based on error types and regions
• split smir Const into TyConst and MirConst
• store the types of ty::Expr arguments in the ty::Expr
• when deriveing, account for HRTB on BareFn fields
• winnow private method candidates instead of assuming any candidate of the right name will apply
• add SingleUseConsts mir-opt pass
• miri: simd_bitmask: nicer error when the mask is too big
• miri: simd_bitmask: work correctly for sizes like 24
• miri: simd_select_bitmask: fix intrinsic name in error
• miri: add support for pclmulqdq intrinsic
• miri: don't panic if time computaton overflows
• miri: fix futex with large timeout ICE
• miri: fix stage in contributing
• stabilize order of MonoItems in CGUs and disallow query_instability lint for rustc_monomorphize
• stabilize Option::take_if
• stabilize binary_heap_as_slice
• stabilize error_in_core
• Allow core_intrinsics when activated (RFC #2011)
• add function core::iter::chain
• offset_of: allow (unstably) taking the offset of slice tail fields
• add FRAC_1_SQRT_2PI constant to f16/f32/f64/f128
• add size_of and size_of_val and align_of and align_of_val to the prelude
• hashbrown: feat: borsh serde
• portable SIMD: implement special swizzles for masks and remove {to, from}_bitmask_vector
• regex: escape invalid UTF-8 bytes in debug output for Match
• cargo lints: Add unknown_lints to lints list
• cargo toml: Convert warnings that licence and readme files do not exist into errors
• cargo toml: remove lib.plugin key support and make it warning
• cargo: proc-macro example from dep no longer affects feature resolution
• cargo: remove __CARGO_GITOXIDE_DISABLE_LIST_FILES env var
• cargo: using --release/debug and --profile together becomes an error
• cargo: rename --out-dir to --artifact-dir
• rustdoc-search: use lowercase, non-normalized name for type search
• rustdoc: add support for --remap-path-prefix
• rustdoc: include trailing commas in wrapped function declarations
• clippy: lint_groups_priority: ignore lints & groups at the same level
• clippy: match_same_arms: add a test case with lifetimes
• clippy: overly_complex_bool_expr: Fix false positive on never type
• clippy: add needless_maybe_sized lint
• clippy: add required parentheses around method receiver
• clippy: dedup nonminimal_bool_methods diags
• clippy: don't lint blocks in closures for blocks_in_conditions
• clippy: fix to_string_in_format_args with macro call receiver
• clippy: fix false positive for needless_character_iteration lint
• clippy: handle const effects inherited from parent correctly in type_certainty
• clippy: lint manual_unwrap_or_default for Result as well
• clippy: make for_each_expr visit closures by default, rename the old version for_each_expr_without_closures
• clippy: only run suboptimal_flops on inherent method calls
• rust-analyzer: add preference modifier for workspace-local crates when using auto import
• rust-analyzer: add version info to status bar item
• rust-analyzer: changed package.json so vscode extension settings have submenus
• rust-analyzer: TOML based config for rust-analyzer
• rust-analyzer: compute native diagnostics in parallel
• rust-analyzer: hide double underscored symbols from symbol search
• rust-analyzer: do not resolve prelude within block modules
• rust-analyzer: ensure that the parent of a SourceRoot cannot be itself
• rust-analyzer: fix generated markers not being patchable in package.json
• rust-analyzer: fix renaming imports of foreign items touching foreign sources
• rust-analyzer: highlight unlinked files consistently with inactive files
• rust-analyzer: incorrect formatting of hover actions
• rust-analyzer: remove extra parse cache from Semantics again
• rust-analyzer: try caching macro calls more aggressively in Semantics

Rust Compiler Performance Triage

This week saw more regressions than wins, caused mostly by code being reorganized within the compiler and a new feature being implemented. There have also been some nice improvements caused by better optimizing spans.

Triage done by @kobzol. Revision range: 1d52972d..b5b13568

Summary:

5 Regressions, 3 Improvements, 4 Mixed; 5 of them in rollups 59 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:

• re-organise the compiler team
• Precise capturing

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] UnsafePinned: allow aliasing of pinned mutable references
• [disposition: postpone] RFC: make Cargo embed dependency versions in the compiled binary

Tracking Issues & PRs

Rust

• [disposition: close] Should we allow StorageLive on a live local?
• [disposition: merge] Tracking Issue for hint::assert_unchecked
• [disposition: merge] Collect relevant item bounds from trait clauses for nested rigid projections
• [disposition: close] conflicting impl since nightly-2024-05-01
• [disposition: merge] Document behavior of create_dir_all wrt. empty path

Cargo

• [disposition: merge] Include vcs_info even if workspace is dirty

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

• [updated] fix links of I/O safety RFC
• [new] RFC: Return Type Notation

Upcoming Events

Rusty Events between 2024-06-12 - 2024-07-10 🦀

Virtual

• 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 | Hybrid - Virtual and In-person (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
• 2024-06-25 | Virtual (Tel Aviv, IL) | Code Mavens
  • Using the Liquid template system in Rust (English)
• 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
• 2024-07-04 | Virtual (Berlin, DE) | OpenTechSchool Berlin + Rust Berlin
  • Rust Hack and Learn | Mirror: Rust Hack n Learn Meetup
• 2024-07-06 | Virtual (Kampala, UG) | Rust Circle Kampala
  • Rust Circle Meetup
• 2024-07-09 | Virtual (Dallas, TX, US) | Dallas Rust
  • Second Tuesday
• 2024-07-10 | Virtual | Centre for eResearch
  • Research Computing With The Rust Programming Language

Asia

• 2024-06-22 | Bangalore, IN | Rust Bangalore
  • June 2024 Rustacean meetup
• 2024-06-30 | Kyoto, JP | Kyoto Rust
  • Rust Talk: Cross Platform Apps

Europe

• 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

• 2024-06-12 | Detroit, MI, US | Detroit Rust
  • Detroit Rust Meet - Ann Arbor
• 2024-06-13 | Spokane, WA, US | Spokane Rust
  • Monthly Meetup: Crafting an Interpreter in Rust, pt. 1
• 2024-06-14 | Spokane, WA, US | Spokane Rust
  • Summer BBQ for Spokane's Local Tech User Groups at Saranac Pub Rooftop!
• 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
• 2024-06-19 | Hybrid - Vancouver, BC, CA | Vancouver Rust
  • Rust Study/Hack/Hang-out
• 2024-06-20 | Seattle, WA, US | Seattle Rust User Group
  • Seattle Rust User Group Meetup
• 2024-06-24 | Somerville, MA, US | Boston Rust Meetup
  • Harvard Square Rust Lunch, June 24
• 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
• 2024-07-05 | Boston, MA, US | Boston Rust Meetup
  • Boston University Rust Lunch, July 5

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

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 like explicit but I hate noise...

– dlevac discussing error handling on /r/golang

Thanks to robin 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