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 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. If you find any errors in this week's issue, please submit a PR.

Updates from Rust Community

Official

• Announcing Rust 1.66.1
• Security advisory for Cargo (CVE-2022-46176)
• Updating the Android NDK in Rust 1.68

Foundation

• Introducing Our Newest Project Grantees

Newsletters

• This Month in Rust OSDev: December 2022
• Rust Nigeria newsletter Issue 13

Project/Tooling Updates

• Announcing turmoil
• rust-analyzer changelog #163
• rustc_codegen_gcc: Progress Report #19
• Fyrox 0.29 Feature Highlights
• Release of how-u-doin; a progress reporting abstraction
• Introducing OkayWAL: A write-ahead log for Rust

Observations/Thoughts

• Rust Atomics and Locks by Mara Bos
• Oh the Crates You'll Go! A 2022 Retrospective
• Rust for Java developers, an introduction
• On Random Numbers
• Potential DoS Vulnerability in Rust Hyper
• Is coding in Rust as bad as in C++?
• Rust vs C++ Formatting
• My impressions of Rust after a year of working with it
• [audio] Fermyon with Matt Butcher

Rust Walkthroughs

• Rust and Default Parameters
• Testing SIMD instructions on ARM with Rust on Android
• Running Zola on WebAssembly
• Who needs Haskell? Straight to Rust Hell
• Sharing Data Among Tasks in Rust Embassy: Synchronization Primitives
• Cross compiling Rust with Drone CI and Gitea

Crate of the Week

This week's crate is schnellru, which contains a fast and flexible LRU map.

Thanks to Squirrel for the suggestion!

Please submit your suggestions and votes for next week!

Call for Participation

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.

• Rust Playground - Call for contributors
• meilisearch - When the lat and lng are strings the wrong error message is returned
• meilisearch - Bad latitude / Bad longitude should share a common message between the invalid sort and invalid filte
• meilisearch - When both lat and lng are missing it doesn't return the right error
• meilisearch - We must return an error for when _geo is not an object
• diesel - A pure rust postgres diesel connection
• diesel - A pure rust mysql diesel connection implementation

If you are a Rust project owner and are looking for contributors, please submit tasks here.

Updates from the Rust Project

443 pull requests were merged in the last week

• playStation Vita support
• add JSON output to -Zdump-mono-stats
• add default and latest stable edition to --edition in rustc (attempt 2)
• split -Zchalk flag into -Ztrait-solver=(classic|chalk|next) flag
• only specify --target by default for -Zgcc-ld=lld on wasm
• do not add noalias in return position
• has_overflow only if value is not within limit
• account for return-position impl Trait in trait in opt_suggest_box_span
• add help diag. for const = Enum missing braces around Enum
• add retry mechanism for rustdoc GUI tests to reduce flakyness
• add type flags support for Ty and Const late-bound variables
• always permit ConstProp to exploit arithmetic identities
• correct detection of elided lifetimes in impl-trait
• default OOM handler: use non-unwinding panic, to match std handler
• detect bindings assigned blocks without tail expressions
• detect closures assigned to binding in block
• do not emit structured suggestion for turbofish with wrong span
• do not emit wrong E0308 suggestion for closure mismatch
• don't deduce a signature that makes a closure cyclic
• point at expressions where inference refines an unexpected type
• point out span where we could introduce higher-ranked lifetime
• reenable limited top-down MIR inlining
• remove invalid case for mutable borrow suggestion
• structured suggestion for &mut dyn Iterator when possible
• suggest impl Fn* and impl Future in -> _ return suggestions
• suggest mut self: &mut Self for ?Sized impls
• suggest adding named lifetime when the return contains value borrowed from more than one lifetimes of function inputs
• suggest using clone when we have &T and T implemented Clone
• suppress type errors that come from private fields
• inference: change a commit_if_ok call to probe
• miri: ignore symbol shim clash when symbol is provided by compiler_builtins
• miri: make env::current_exe work on Windows
• only include metadata for non-dynamic libraries in rustc-dev
• merge borrowck permission checks
• don't normalize in AstConv
• perform SimplifyLocals before ConstProp
• use FxIndexSet when updating obligation causes in adjust_fulfillment_errors_for_expr_obligation
• shrink ParseResult in the hot path
• stabilize main_separator_str
• Split*::as_str refactor
• loosen the bound on the Debug implementation of Weak
• customize Debug impl for OnceWith & RepeatWith
• futures: add PhantomData marker to Context to make Context !Send and !Sync
• futures: set to None only if necessary
• arch: stabilize cmpxchg16b instrinsic
• cargo: cargo by default saves credentials to .cargo/credentials.toml
• cargo: fix panic on target dependency errors
• rustdoc: fix rustdoc ICE on bad typedef with mismatching types
• clippy: drop_ref: don't lint idiomatic in match arm
• clippy: arithmetic_side_effects: Consider negative numbers and add more tests
• clippy: don't lint field_reassign when field in closure
• clippy: expand derivable-impls to cover enums with a default unit variant
• clippy: fix false positive in single_element_loop
• clippy: fix empty_structs_with_brackets suggestion errors
• clippy: make the iter_kv_map lint handle ref/mut annotations
• clippy: suggest using Path for comparing extensions
• clippy: trim paths in box_default and default_trait_access/clone_on_copy suggestions
• rust-analyzer: add wrapping/checked/saturating assist
• rust-analyzer: apply fallback before final obligation resolution
• rust-analyzer: complete record enum variants without parens when snippets are disabled
• rust-analyzer: extract_expressions_from_format_string
• rust-analyzer: add unqualify_method_call assist
• rust-analyzer: add action to expand a declarative macro once, inline. Fixes #13598
• rust-analyzer: add the ability to limit the number of threads launched by main_loop
• rust-analyzer: colorize cargo check diagnostics in VSCode via text decorations
• rust-analyzer: add generic TypeBoundList in generated derivable impl
• rust-analyzer: generate async delegate methods
• rust-analyzer: keep whitespace in extract function handler
• rust-analyzer: only set machine-applicable rustc diagnostics as preferred
• rust-analyzer: unescape inline module names in module resolution
• rust-analyzer: postfix adjustment hints
• rust-analyzer: skip lifetime elision on fn pointers and fn trait types
• rust-analyzer: use ZWNJ to prevent VSCode from forming ligatures between hints and code
• rust-analyzer: use diagnostic code as link to full message

Rust Compiler Performance Triage

A very quiet week, with few changes in either direction, and none of significant magnitude.

Triage done by @simulacrum. Revision range: b435960..0442fba

1 Regressions, 1 Improvements, 3 Mixed; 1 of them in rollups 48 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:

• Add core::mem::offset_of! RFC

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] Create an Operational Semantics Team
• [disposition: merge] RFC: Move std::net::IpAddr types into core::net.

Tracking Issues & PRs

• [disposition: merge] Add SEMICOLON_IN_EXPRESSIONS_FROM_MACROS to future-incompat report
• [disposition: merge] Tracking issue for RFC 2515, "Permit impl Trait in type aliases"
• [disposition: merge] Check ADT fields for copy implementations considering regions
• [disposition: merge] Stabilise inline_const
• [disposition: merge] Partial stabilization of once_cell
• [disposition: merge] Loosen From<&[T]> for Box<[T]> bound to T: Clone
• [disposition: merge] Leak amplification for peek_mut() to ensure BinaryHeap's invariant is always met
• [disposition: merge] rustdoc: simplify JS search routine by not messing with lev distance
• [disposition: merge] Only include stable lints in rustdoc::all group

New and Updated RFCs

• [new] The #[diagnostic] attribute namespace
• [new] RFC: Multi-Type Return Position Impl Trait (MTRPIT)
• [new] RFC: re-export stdlib macros from submodules
• [new] Command improvements for ergonomics and error handling

Call 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:

• No RFCs issued a call for testing 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.

Upcoming Events

Rusty Events between 2023-01-11 - 2023-02-08 🦀

Virtual

• 2023-01-11 | Virtual (Boulder, CO, US) | Boulder Elixir and Rust
  • Monthly Meetup
• 2023-01-12 | Virtual (San Francisco, CA, US; Stockholm, SE; New York, NY US) | Microsoft Reactor New York and Microsoft Reactor San Francisco and Microsoft Reactor Stockholm
  • Crack code interview problems in Rust - Ep. 1 | Stockholm Mirror | New York Mirror
• 2023-01-12 | Virtual (Nürnberg, DE) | Rust Nuremberg
  • Rust Nürnberg online
• 2023-01-14 | Virtual | Rust GameDev
  • Rust GameDev Monthly Meetup
• 2023-01-16 | Virtual (San Francisco, CA, US; São Paulo, BR; New York, NY, US) | Microsoft Reactor San Francisco and Microsoft Reactor São Paulo and Microsoft Reactor New York
  • Primeros pasos con Rust - Qué es y Configuración el entorno de desarrollo | São Paulo Mirror | New York Mirror
• 2023-01-17 | Virtual (Berlin, DE) | OpenTechSchool Berlin
  • Rust Hack and Learn
• 2023-01-17 | Virtual (San Francisco, CA, US; São Paulo, BR; New York, NY, US) | Microsoft Reactor San Francisco and Microsoft Reactor São Paulo and Microsoft Reactor New York
  • Primeros pasos con Rust - Creación del primer programa de Rust | *São Paulo Mirror | New York Mirror
• 2023-01-17 | Virtual (Washington, DC, US) | Rust DC
  • Mid-month Rustful
• 2023-01-18 | Virtual (San Francisco, CA, US; São Paulo, BR; New York, NY US) | Microsoft Reactor San Francisco and Microsoft Reactor São Paulo and Microsoft Reactor New York
  • Primeros pasos con Rust: QA y horas de comunidad | New York Mirror | San Francisco Mirror | Sao Paulo Mirror
• 2023-01-18 | Virtual (Vancouver, BC, CA) | Vancouver Rust
  • Rust Study/Hack/Hang-out
• 2023-01-19 | Virtual (Redmond, WA, US; San Francisco, CA, US; New York, NY, US; Stockholm, SE) | Microsoft Reactor Redmond and Microsoft Reactor New York and Microsoft Reactor San Francisco and Microsoft Reactor Stockholm
  • Crack code interview problems in Rust - Ep. 2 | New York Mirror | San Francisco Mirror | Stockholm Mirror
• 2023-01-19 | Virtual (Stuttgart, DE) | Rust Community Stuttgart
  • Rust-Meetup
• 2023-01-23 | Virtual (Durham, NC, US) | Triangle Rust
  • Online Code and Chat
• 2023-01-23 | Virtual (New York, NY, US; San Francisco, CA, US) | Microsoft Reactor New York and Microsoft Reactor San Francisco
  • Primeros pasos con Rust - Condiciones con expresiones if/else en Rust | San Francisco Mirror
• 2023-01-24 | Virtual (Redmond, WA, US; New York, NY, US) | Microsoft Reactor Redmond and Microsoft Reactor New York and Microsoft Reactor San Francisco
  • Primeros pasos con Rust - Uso de bucles para iterar por datos en Rust | New York Mirror | San Francisco Mirror
• 2023-01-25 | Virtual (Redmond, WA, US; San Francisco, CA, US) | Microsoft Reactor Redmond | Microsoft Reactor San Francisco
  • Primeros pasos con Rust: QA y horas de comunidad | San Francisco Mirror
• 2023-01-26 | Virtual (Charlottesville, VA, US) | Charlottesville Rust Meetup
  • Rust Lightning Talks!
• 2023-01-26 | Virtual (Redmond, WA, US; San Francisco, CA, US; New York, NY, US; Stockholm, SE) | Microsoft Reactor Redmond and Microsoft Reactor New York and Microsoft Reactor San Francisco and Microsoft Reactor Stockholm
  • Crack code interview problems in Rust - Ep. 3 | New York Mirror | San Francisco Mirror | Stockholm Mirror
• 2023-01-30 | Virtual (Redmond, WA, US; New York, NY, US; San Francisco, CA, US) | Microsoft Reactor Redmond and Microsoft Reactor New York and Microsoft Reactor San Francisco
  • Primeros pasos con Rust - Control de errores en Rust | New York Mirror | San Francisco Mirror
• 2023-01-31 | Virtual (Berlin, DE) | OpenTechSchool Berlin
  • Rust Hack and Learn
• 2023-01-31 | Virtual (Dallas, TX, US) | Dallas Rust
  • Last Tuesday
• 2023-01-31 | Virtual (Redmond, WA, US; New York, NY, US; San Francisco, CA, US) | Microsoft Reactor Redmond and Microsoft Reactor New York and Microsoft Reactor San Francisco
  • Primeros pasos con Rust - Compresión de cómo Rust administra la memoria | New York Mirror | San Francisco Mirror
• 2023-02-01 | Virtual (Indianapolis, IN, US) | Indy Rust
  • Indy.rs - with Social Distancing
• 2023-02-01 | Virtual (Redmond, WA, US; New York, NY, US; San Francisco, CA, US) | Microsoft Reactor Redmond and Microsoft Reactor New York and Microsoft Reactor San Francisco
  • Primeros pasos con Rust: QA y horas de comunidad | New York Mirror | San Francisco Mirror
• 2023-02-01 | Virtual (Stuttgart, DE) | Rust Community Stuttgart
  • Rust-Meetup
• 2023-02-06| Virtual (Redmond, WA, US; New York, NY, US; San Francisco, CA, US) | Microsoft Reactor Redmond and Microsoft Reactor New York and Microsoft Reactor San Francisco
  • Primeros pasos con Rust - Implementación de tipos y rasgos genéricos | New York Mirror | San Francisco Mirror
• 2023-02-07 | Virtual (Beijing, CN) | WebAssembly and Rust Meetup (Rustlang)
  • Monthly WasmEdge Community Meeting, a CNCF sandbox WebAssembly runtime
• 2023-02-07 | Virtual (Buffalo, NY, US) | Buffalo Rust Meetup
  • Buffalo Rust User Group, First Tuesdays
• 2023-02-07 | Virtual (Redmond, WA, US; New York, NY, US; San Francisco, CA, US) | Microsoft Reactor Redmond and Microsoft Reactor New York and Microsoft Reactor San Francisco
  • Primeros pasos con Rust - Módulos, paquetes y contenedores de terceros | New York Mirror | San Francisco Mirror
• 2023-02-08 | Virtual (Redmond, WA, US; New York, NY, US; San Francisco, CA, US) | Microsoft Reactor Redmond and Microsoft Rector New York and Microsoft Reactor San Francisco
  • Primeros pasos con Rust: QA y horas de comunidad | New York Mirror | San Francisco Mirror

Asia

• 2023-01-15 | Tokyo, JP | Tokyo Rust Meetup
  • Property-Based Testing in Rust

Europe

• 2023-01-12 | Enschede, NL | Dutch Rust Meetup
  • Rust Meetup - Subject TBA
• 2023-01-20 | Stuttgart, DE | Rust Community Stuttgart
  • OnSite Meeting
• 2023-01-25 | Paris, FR | Rust Paris
  • Rust Paris meetup #55
• 2023-01-26 | Copenhagen, DE | Copenhagen Rust Meetup Group
  • Rust Hack Night #32
• 2023-02-02 | Hamburg, DE | Rust Meetup Hamburg
  • Rust Hack & Learn February 2023
• 2023-02-02 | Lyon, FR | Rust Lyon
  • Rust Lyon meetup #01

North America

• 2023-01-11 | Austin, TX, US | Rust ATX
  • Rust Lunch
• 2023-01-17 | San Francisco, CA, US | San Francisco Rust Study Group
  • Rust Hacking in Person
• 2023-01-26 | Copenhagen, DK | Copenhagen Rust group
  • Rust Hack Night #32
• 2023-01-26 | Lehi, UT, US | Utah Rust
  • Building a Rust Playground with WASM and Lane and Food!

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

Now macros are fine, I mean we use them for implementing internals and you know if you have something that [...] needs to be implemented for lots and lots of different concrete types, then macros are a fine choice for that, but exposing that to users is something to be very careful about.

– Raph Levien

llogiq is a tad sad there were no suggestions, but still likes the quote he ended up with!

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