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

• Types Team Update and Roadmap

Project/Tooling Updates

• Rustlings Rewrite
• iroh 0.19.0 - Make it your own
• Announcing Polars 1.0
• rust-analyzer changelog #240
• r3bl_cmdr v0.0.14 released
• r3bl_tui v0.5.6 released
• Danube - Pub/Sub messaging broker
• what-the-time 1.0.0
• Meilisearch releases v1.9
• derive-deftly (the template-based derive macro facility) is nearing 1.x - call for review/testing

Observations/Thoughts

• Ergonomic Self-Referential Types for Rust
• More thoughts on claiming
• Async closures
• Rust has three reference types!
• sans-IO: The secret to effective Rust for network services
• [audio] OxidOS with Alexandru Radovici

Rust Walkthroughs

• Resolving Rust Symbols
• #![doc = include_str!()] with intra-doc links
• The Minimal Rust-Wasm Setup
• Build with Naz : Markdown parser in Rust and nom from r3bl_tui
• Adding compile-time safety to the AWS SDK with syn's Visit trait
• Adding GraphQL Support to Loco with Seaography
• Rust patterns: Don't put any code in mod.rs or lib.rs files
• [series] Master Hexagonal Architecture in Rust (part 3): Service, the heart of hexagonal architecture

Miscellaneous

• FizzBuzz Multithreaded - synchronization with rendezvous channels
• [video] Zelda Hessler discusses the AWS SDK for Rust

Crate of the Week

This week's crate is asak, a terminal-based audio recording/playback TUI.

Despite a lamentable lack of suggestions this week, llogiq is reasonably pleased with his choice.

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.

• diesel- Add support for currently unsupported range operators and methods

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

408 pull requests were merged in the last week

• rustc_data_structures: Explicitly check for 64-bit atomics support
• add () to the marker_impls macro for ConstParamTy
• add .ignore file to make config.toml searchable in vscode
• add more constants, functions, and tests for f16 and f128
• ast: standardize visiting order
• ast: standardize visiting order for attributes and node IDs
• automatically taint InferCtxt when errors are emitted
• avoid MIR bloat in inlining
• avoid cloning jump threading state when possible
• coverage: avoid getting extra unexpansion info when we don't need it
• coverage: make #[coverage(..)] apply recursively to nested functions
• de-duplicate all consecutive native libs regardless of their options
• delegation: ast lowering refactor
• deny use<> for RPITITs
• detect unused structs which derived Default
• do not ICE when suggesting dereferencing closure arg
• don't ICE during RPITIT refinement checking for resolution errors after normalization
• don't suggest awaiting in closure patterns
• eliminate the distinction between PREC_POSTFIX and PREC_PAREN precedence level
• enable const casting for f16 and f128
• fix x86_64 code being produced for bare-metal LoongArch targets' compiler_builtins
• fix an error suggestion for E0121 when using placeholder _ as return types on function signature
• fix bad replacement for unsafe extern block suggestion
• prefer (*p).clone to p.clone if the p is a raw pointer
• ignore llvm::Lld if lld is not enabled
• implement new effects desugaring
• improve unsafe extern blocks diagnostics
• introduce a rustc_ attribute to dump all the DefId parents of a DefId
• less maybe_whole_expr, take 2
• let's #[expect] some lints: Stabilize lint_reasons (RFC 2383)
• linker: refactor interface for passing arguments to linker
• make feature(effects) require -Znext-solver
• make cargo submodule optional
• mark assoc tys live only if the corresponding trait is live
• move binder and polarity parsing into parse_generic_ty_bound
• not use offset when there is not ends with brace
• patchable-function-entry: add unstable compiler flag and attribute
• print TypeId as a u128 for Debug
• un-unsafe the StableOrd trait
• remove (deprecated & unstable) {to,from}_bits pointer methods
• remove f16 and f128 ICE paths from smir
• remove more PtrToPtr casts in GVN
• remove unnecessary SeqCst in impl fmt::Pointer for AtomicPtr
• resolve: tweak some naming around import ambiguities
• show used attribute's kind for user when find it isn't applied to a static variable
• stall computing instance for drop shim until it has no unsubstituted const params
• support fetching Attribute of items
• switch back non_local_definitions lint to allow-by-default
• tighten fn_decl_span for async blocks
• transmute size check: properly account for alignment
• tweak FlatPat::new to avoid a temporarily-invalid state
• tweak a confusing comment in create_match_candidates
• unify dylib and bin_helpers and create shared_helpers::parse_value_from_args
• use clang-format in tidy to check the C++ code style under llvm-wrapper
• use full expr span for return suggestion on type error/ambiguity
• various rustc_codegen_ssa cleanups
• various refactorings to rustc_interface
• miri: iter_exported_symbols: also walk used statics in local crate
• miri: remove GetCurrentProcessId's frame_in_std check
• stabilize PanicInfo::message() and PanicMessage
• stabilize duration_abs_diff
• mark Hasher::finish as #[must_use]
• std: separate TLS key creation from TLS access
• cargo: allow unexpected_builtin_cfgs lint in user_specific_cfgs test
• cargo: gix: remove revision feature from cargo
• cargo: make it clear that CARGO_CFG_TARGET_FAMILY is multi-valued
• cargo: test: fix several assertions
• cargo: test: omit target-dir name
• cargo: test: replace glob with explicit unordered calls
• rustdoc: check if the disambiguator matches its suffix
• clippy: doc_lazy_continuation: blank comment line for gap
• clippy: add error message to manual_inspect lint
• clippy: don't lint assertions_on_constants on any const assertions
• clippy: fix doc_markdown DevOps false positive
• clippy: implement a lint to replace manual bit rotations with rotate_left/rot…
• rust-analyzer: do not normalize use foo::{self} to use foo
• rust-analyzer: add bool_to_enum assist for parameters
• rust-analyzer: completions after async kw
• rust-analyzer: fix expression scope calculation when within macro expansions
• rust-analyzer: pass cargo extra args when debugging
• rust-analyzer: quality of life improvements to term search
• rust-analyzer: use proper ImplTraits in insert_inference_vars_for_impl_trait

Rust Compiler Performance Triage

2024-07-02 Triage Log

We saw a large set of primary benchmarks regress, mostly due to PR #120924 (lint_reasons and #[expect]) and PR #120639 (new effects desugaring). Separate from those, there are a couple rollup PRs (#127076, #127096) with some regressions that were limited to relatively few benchmarks; pnkfelix was unable to isolate a injecting PR that can be identified as a root cause (outside assistance welcome!).

Triage done by @pnkfelix. Revision range: c3d7fb39..cf2df68d

4 Regressions, 3 Improvements, 11 Mixed; 7 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: * RFC: Unblock Cargo feature metadata

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: #[derive(SmartPointer)]

Tracking Issues & PRs

Rust

• [disposition: merge] Tracking issue for const char conversions
• [disposition: merge] Don't make statement nonterminals match pattern nonterminals
• [disposition: merge] Allow #[deny] inside #[forbid] as a no-op
• [disposition: merge] Tracking issue for function attribute #[coverage]
• [disposition: merge] Bump elided_lifetimes_in_associated_constant to deny
• [disposition: merge] Tracking Issue for const_cstr_from_ptr
• [disposition: merge] Deny keyword lifetimes pre-expansion

Cargo

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

Language Team

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

Language Reference

• No Language Reference Tracking Issues or PRs 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] Async closures

Upcoming Events

Rusty Events between 2024-07-03 - 2024-07-31 🦀

Virtual

• 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 | Rust for Lunch
  • July 2024 Rust for Lunch
• 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
• 2024-07-11 | Virtual (Charlottesville, NC, US) | Charlottesville Rust Meetup
  • Crafting Interpreters in Rust Collaboratively
• 2024-07-11 | Hybrid - Virtual and In-person (Mexico City, DF, MX) | Rust MX
  • Programación de sistemas con Rust
• 2024-07-11 | Virtual (Nürnberg, DE) | Rust Nuremberg
  • Rust Nürnberg online
• 2024-07-11 | Virtual (Tel Aviv, IL) | Code Mavens
  • Reading JSON files in Rust (English)
• 2024-07-16 | Virtual (Tel Aviv, IL) | Code Mavens
  • Web development in Rust using Rocket - part 2 (English)
• 2024-07-17 | Hybrid - Virtual and In-person (Vancouver, BC, CA) | Vancouver Rust
  • Rust Study/Hack/Hang-out
• 2024-07-18 | Virtual (Berlin, DE) | OpenTechSchool Berlin + Rust Berlin
  • Rust Hack and Learn | Mirror: Rust Hack n Learn Meetup
• 2024-07-23| Hybrid - Virtual and In-Person (München/Munich, DE) | Rust Munich
  • Rust Munich 2024 / 2 - hybrid
• 2024-07-24 | Virtual | Women in Rust
  • Lunch & Learn: Exploring Rust API Use Cases
• 2024-07-25 | Virtual (Charlottesville, NC, US) | Charlottesville Rust Meetup
  • Crafting Interpreters in Rust Collaboratively
• 2024-07-27 | Hybrid - Virtual and In-Person (Kyiv, UA) | UA Rust
  • UARust Conference 2024
• 2024-07-30 | Virtual (Dallas, TX, US) | Dallas Rust
  • Last Tuesday

Asia

• 2024-07-03 | Tokyo, JP | Tokyo Rust Meetup
  • I Was Understanding WASM All Wrong!

Europe

• 2024-07-10 | Reading, UK | Reading Rust Workshop
  • Reading Rust Meetup - July
• 2024-07-11 | Prague, CZ | Rust Prague
  • Rust Meetup Prague (July 2024)
• 2024-07-16 | Leipzig, DE | Rust - Modern Systems Programming in Leipzig
  • Building a REST API in Rust using Axum, SQLx and SQLite
• 2024-07-16 | Mannheim, DE | Hackschool - Rhein-Neckar
  • Nix Your Bugs & Rust Your Engines #4
• 2024-07-23 | Hybrid - Virtual and In-Person (München/Munich, DE) | Rust Munich
  • Rust Munich 2024 / 2 - hybrid
• 2024-07-25 | Berlin, DE | OpenTechSchool Berlin + Rust Berlin
  • Rust and Tell - Title
• 2024-07-27 | Augsburg, DE | Rust Meetup Augsburg
  • Augsburg Rust Meetup #8: Einführung in Machine Learning mit Rust
• 2024-07-30 | Basel, CH | Rust Basel
  • Rust Meetup #9

North America

• 2024-07-05 | Boston, MA, US | Boston Rust Meetup
  • Boston University Rust Lunch, July 5
• 2024-07-11 | Hybrid - Mexico City, DF, MX | Rust MX
  • Programación de sistemas con Rust
• 2024-07-11 | Mountain View, CA, US | Mountain View Rust Meetup
  • Rust Meetup at Hacker Dojo
• 2024-07-17 | Hybrid - Vancouver, BC, CA | Vancouver Rust
  • Rust Study/Hack/Hang-out
• 2024-07-18 | Nashville, TN, US | Music City Rust Developers
  • Music City Rust Developers : holding pattern
• 2024-07-18 | Seattle, WA, US | Seattle Rust User Group
  • Seattle Rust User Group Meetup
• 2024-07-24 | Austin, TX, US | Rust ATC
  • Rust Lunch - Fareground
• 2024-07-27 | Hybrid - Virtual and In-Person (Kyiv, UA) | UA Rust
  • UARust Conference 2024

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

the compiler usually doesn't complain about [you] doing undefined behavior because it doesn't know that you're doing undefined behavior.

– Nilstrieb on GitHub

Thanks to scottmcm 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