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 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

Project/Tooling Updates

• Strobe Crate
• System dependencies are hard (so we made them easier)

Observations/Thoughts

• Trying to invent a better substring search algorithm
• Improving Node.js with Rust-Wasm Library
• Mixing C# and Rust - Interop
• A fresh look on incremental zero copy serialization
• Make the Rust compiler 5% faster with this one weird trick
• Part 3: Rowing Afloat Datatype Boats
• Recreating concurrent futures combinators in smol
• Unpacking some Rust ergonomics: getting a single Result from an iterator of them
• Idea: "Using Rust", a living document
• Object Soup is Made of Indexes
• Analyzing Data 180,000x Faster with Rust
• Issue #10: Serving HTML
• Rust vs C on an ATTiny85; an embedded war story

Rust Walkthroughs

• Fully Automated Releases for Rust Projects
• Make your Rust code unit testable with dependency inversion
• Nine Rules to Formally Validate Rust Algorithms with Dafny (Part 2): Lessons from Verifying the range-set-blaze Crate
• [video] Let's write a message broker using QUIC - Broke But Quick Episode 1
• [video] Publishing Messages over QUIC Streams!! - Broke But Quick episode 2

Miscellaneous

• [video] Associated types in Iterator bounds
• [video] Rust and the Age of High-Integrity Languages
• [video] Implementing (part of) a BitTorrent client in Rust

Crate of the Week

This week's crate is cargo-show-asm, a cargo subcommand to show the optimized assembly of any function.

Thanks to Kornel 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.

• Hyperswitch (Hacktoberfest)- [FEATURE] separate payments_session from payments core
• Hyperswitch (Hacktoberfest)- [NMI] Use connector_response_reference_id as reference to merchant
• Hyperswitch (Hacktoberfest)- [Airwallex] Use connector_response_reference_id as reference to merchant
• Hyperswitch (Hacktoberfest)- [Worldline] Use connector_response_reference_id as reference to merchant
• Ockam - Make ockam project delete (no args) interactive by asking the user to choose from a list of space and project names to delete (tuify)
• Ockam - Validate CBOR structs according to the cddl schema for authenticator/direct/types
• Ockam - Slim down the NodeManagerWorker for node / node status

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

Updates from the Rust Project

397 pull requests were merged in the last week

• rewrite gdb pretty-printer registration
• add FileCheck annotations to mir-opt tests
• add MonoItems and Instance to stable_mir
• add a csky-unknown-linux-gnuabiv2hf target
• add a test showing failing closure signature inference in new solver
• add new simpler and more explicit syntax for check-cfg
• add stable Instance::body() and RustcInternal trait
• automatically enable cross-crate inlining for small functions
• avoid a track_errors by bubbling up most errors from check_well_formed
• avoid having rustc_smir depend on rustc_interface or rustc_driver
• coverage: emit mappings for unused functions without generating stubs
• coverage: emit the filenames section before encoding per-function mappings
• coverage: fix inconsistent handling of function signature spans
• coverage: move most per-function coverage info into mir::Body
• coverage: simplify the injection of coverage statements
• disable missing_copy_implementations lint on non_exhaustive types
• do not bold main message in --error-format=short
• don't ICE when encountering unresolved regions in fully_resolve
• don't compare host param by name
• don't crash on empty match in the nonexhaustive_omitted_patterns lint
• duplicate ~const bounds with a non-const one in effects desugaring
• eliminate rustc_attrs::builtin::handle_errors in favor of emitting errors directly
• fix a performance regression in obligation deduplication
• fix implied outlives check for GAT in RPITIT
• fix spans for removing .await on for expressions
• fix suggestion for renamed coroutines feature
• implement an internal lint encouraging use of Span::eq_ctxt
• implement jump threading MIR opt
• implement rustc part of RFC 3127 trim-paths
• improve display of parallel jobs in rustdoc-gui tester script
• initiate the inner usage of cfg_match (Compiler)
• lint non_exhaustive_omitted_patterns by columns
• location-insensitive polonius: consider a loan escaping if an SCC has member constraints applied only
• make #[repr(Rust)] incompatible with other (non-modifier) representation hints like C and simd
• make rustc_onunimplemented export path agnostic
• mention into_iter on borrow errors suggestions when appropriate
• mention the syntax for use on mod foo; if foo doesn't exist
• panic when the global allocator tries to register a TLS destructor
• point at assoc fn definition on type param divergence
• preserve unicode escapes in format string literals when pretty-printing AST
• properly account for self ty in method disambiguation suggestion
• report unused_import for empty reexports even it is pub
• special case iterator chain checks for suggestion
• strict provenance unwind
• suggest ; after bare match expression E0308
• suggest constraining assoc types in more cases
• suggest relaxing implicit type Assoc: Sized; bound
• suggest removing redundant arguments in format!()
• uplift movability and mutability, the simple way
• miri: avoid a linear scan over the entire int_to_ptr_map on each deallocation
• miri: fix rounding mode check in SSE4.1 round functions
• miri: intptrcast: remove information about dead allocations
• disable effects in libcore again
• add #[track_caller] to Option::unwrap_or_else
• specialize Bytes<R>::next when R is a BufReader
• make TCP connect handle EINTR correctly
• on Windows make read_dir error on the empty path
• hashbrown: add low-level HashTable API
• codegen_gcc: add support for NonNull function attribute
• codegen_gcc: fix #[inline(always)] attribute and support unsigned comparison for signed integers
• codegen_gcc: fix endianness
• codegen_gcc: fix int types alignment
• codegen_gcc: optimize popcount implementation
• codegen_gcc: optimize u128/i128 popcounts further
• cargo add: Preserve more comments
• cargo remove: Preserve feature comments
• cargo replace: Partial-version spec support
• cargo: Provide next steps for bad -Z flag
• cargo: Suggest cargo-search on bad commands
• cargo: adjust -Zcheck-cfg for new rustc syntax and behavior
• cargo: if there's a version in the lock file only use that exact version
• cargo: make the precise field of a source an Enum
• cargo: print environment variables for build script executions with -vv
• cargo: warn about crate name's format when creating new crate
• rustdoc: align stability badge to baseline instead of bottom
• rustdoc: avoid allocating strings primitive link printing
• clippy: map_identity: allow closure with type annotations
• clippy: map_identity: recognize tuple identity function
• clippy: add lint for struct field names
• clippy: don't emit needless_pass_by_ref_mut if the variable is used in an unsafe block or function
• clippy: make multiple_unsafe_ops_per_block ignore await desugaring
• clippy: needless pass by ref mut closure non async fn
• clippy: now declare_interior_mutable_const and borrow_interior_mutable_const respect the ignore-interior-mutability configuration entry
• clippy: skip if_not_else lint for '!= 0'-style checks
• clippy: suggest passing function instead of calling it in closure for option_if_let_else
• clippy: warn missing_enforced_import_renames by default
• rust-analyzer: generate descriptors for all unstable features
• rust-analyzer: add command for only opening external docs and attempt to fix vscode-remote issue
• rust-analyzer: add incorrect case diagnostics for module names
• rust-analyzer: fix VS Code detection for Insiders version
• rust-analyzer: import trait if needed for unqualify_method_call assist
• rust-analyzer: pick a better name for variables introduced by replace_is_some_with_if_let_some
• rust-analyzer: store binding mode for each instance of a binding independently
• perf: add NES emulation runtime benchmark

Rust Compiler Performance Triage

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 f16 and f128 float types
• Unicode and escape codes in literals

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

• No RFCs entered Final Comment Period this week.

Tracking Issues & PRs

• [disposition: merge] Consider alias bounds when computing liveness in NLL (but this time sound hopefully)
• [disposition: close] regression: parameter type may not live long enough
• [disposition: merge] Remove support for compiler plugins.
• [disposition: merge] rustdoc: Document lack of object safety on affected traits
• [disposition: merge] Stabilize Ratified RISC-V Target Features
• [disposition: merge] Tracking Issue for const mem::discriminant

New and Updated RFCs

• [new] eRFC: #[should_move] attribute for per-function opting out of Copy semantics

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 2023-10-25 - 2023-11-22 🦀

Virtual

• 2023-10-30 | Virtual (Melbourne, VIC, AU) | Rust Melbourne
  • (Hybrid - online & in person) October 2023 Rust Melbourne Meetup
• 2023-10-31 | Virtual (Europe / Africa) | Rust for Lunch
  • Rust Meet-up
• 2023-11-01 | Virtual (Cardiff, UK)| Rust and C++ Cardiff
  • ECS with Bevy Game Engine
• 2023-11-01 | Virtual (Indianapolis, IN, US) | Indy Rust
  • Indy.rs - with Social Distancing
• 2023-11-02 | Virtual (Charlottesville, NC, US) | Charlottesville Rust Meetup
  • Crafting Interpreters in Rust Collaboratively
• 2023-11-07 | Virtual (Berlin, DE) | OpenTechSchool Berlin
  • Rust Hack and Learn | Mirror
• 2023-11-07 | Virtual (Buffalo, NY, US) | Buffalo Rust Meetup
  • Buffalo Rust User Group, First Tuesdays
• 2023-11-09 | Virtual (Nuremberg, DE) | Rust Nuremberg
  • Rust Nürnberg online
• 2023-11-14 | Virtual (Dallas, TX, US) | Dallas Rust
  • Second Tuesday
• 2023-11-15 | Virtual (Cardiff, UK)| Rust and C++ Cardiff
  • Building Our Own Locks (Atomics & Locks Chapter 9)
• 2023-11-15 | Virtual (Richmond, VA, US) | Linux Plumbers Conference
  • Rust Microconference in LPC 2023 (Nov 13-16)
• 2023-11-15 | Virtual (Vancouver, BC, CA) | Vancouver Rust
  • Rust Study/Hack/Hang-out
• 2023-11-16 | Virtual (Charlottesville, NC, US) | Charlottesville Rust Meetup
  • Crafting Interpreters in Rust Collaboratively
• 2023-11-07 | Virtual (Berlin, DE) | OpenTechSchool Berlin
  • Rust Hack and Learn | Mirror
• 2023-11-21 | Virtual (Washington, DC, US) | Rust DC
  • Mid-month Rustful

Europe

• 2023-10-25 | Dublin, IE | Rust Dublin
  • Biome, web development tooling with Rust
• 2023-10-25 | Paris, FR | Rust Paris
  • Rust for the web - Paris meetup #61
• 2023-10-25 | Zagreb, HR | impl Zagreb for Rust
  • Rust Meetup 2023/10: Lunatic
• 2023-10-26 | Augsburg, DE | Rust - Modern Systems Programming in Leipzig
  • Augsburg Rust Meetup #3
• 2023-10-26 | Copenhagen, DK | Copenhagen Rust Community
  • Rust metup #41 sponsored by Factbird
• 2023-10-26 | Delft, NL | Rust Nederland
  • Rust at TU Delft
• 2023-10-26 | Lille, FR | Rust Lille
  • Rust Lille #4 at SFEIR
• 2022-10-30 | Stockholm, SE | Stockholm Rust
  • Rust Meetup @Aira + Netlight
• 2023-11-01 | Cologne, DE | Rust Cologne
  • Web-applications with axum: Hello CRUD!
• 2023-11-07 | Bratislava, SK | Bratislava Rust Meetup Group
  • Rust Meetup by Sonalake
• 2023-11-07 | Brussels, BE | Rust Aarhus
  • Rust Aarhus - Rust and Talk beginners edition
• 2023-11-07 | Lyon, FR | Rust Lyon
  • Rust Lyon Meetup #7
• 2023-11-09 | Barcelona, ES | BcnRust
  • 11th BcnRust Meetup
• 2023-11-09 | Reading, UK | Reading Rust Workshop
  • Reading Rust Meetup at Browns
• 2023-11-21 | Augsburg, DE | Rust - Modern Systems Programming in Leipzig
  • GPU processing in Rust
• 2023-11-23 | Biel/Bienne, CH | Rust Bern
  • Rust Talks Bern @ Biel: Embedded Edition

North America

• 2023-10-25 | Austin, TX, US | Rust ATX
  • Rust Lunch - Fareground
• 2023-10-25 | Chicago, IL, US | Deep Dish Rust
  • Rust Happy Hour
• 2023-11-01 | Brookline, MA, US | Boston Rust Meetup
  • Boston Common Rust Lunch
• 2023-11-08 | Boulder, CO, US | Boulder Rust Meetup
  • Let's make a Discord bot!
• 2023-11-14 | New York, NY, US | Rust NYC
  • Rust NYC Monthly Mixer: Share, Show, & Tell! 🦀
• 2023-11-14 | Seattle, WA, US | Cap Hill Rust Coding/Hacking/Learning
  • Rusty Coding/Hacking/Learning Night
• 2023-11-15 | Richmond, VA, US + Virtual | Linux Plumbers Conference
  • Rust Microconference in LPC 2023 (Nov 13-16)
• 2023-11-16 | Nashville, TN, US | Music City Rust Developers
  • Python loves Rust!
• 2023-11-16 | Seattle, WA, US | Seattle Rust User Group
  • Seattle Rust User Group Meetup
• 2023-11-21 | San Francisco, CA, US | San Francisco Rust Study Group
  • Rust Hacking in Person
• 2023-11-22 | Austin, TX, US | Rust ATX
  • Rust Lunch - Fareground

Oceania

• 2023-10-26 | Brisbane, QLD, AU | Rust Brisbane
  • October Meetup
• 2023-10-30 | Melbourne, VIC, AU + Virtual | Rust Melbourne
  • (Hybrid - in person & online) October 2023 Rust Melbourne Meetup
• 2023-11-21 | Christchurch, NZ | Christchurch Rust Meetup Group
  • Christchurch Rust meetup meeting

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

When your Rust build times get slower after adding some procedural macros:

We call that the syn tax :ferris:

– Janet on Fosstodon

Thanks to Jacob Pratt 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