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

Official

• 2022 Annual Rust Survey Results
• Security advisory for Cargo (CVE-2023-38497)
• Announcing Rust 1.71.1
• Rotating Rust compiler team leadership

Foundation

• Announcing Speakers & Schedule for Inaugural Rust Global Event

Newsletters

• This Month in Rust OSDev: July 2023
• Rust Nigeria Issue 20

Project/Tooling Updates

• Turbocharging Rust Code Verification
• Changelog #193
• This Week in Ars Militaris #5

Observations/Thoughts

• No telemetry in the Rust compiler: metrics without betraying user privacy
• A failed experiment with Rust static dispatch
• nesting allocators
• Allocator trait 1: Let’s talk about the Allocator trait
• How to improve Rust compiler’s CI in 2023
• Rust Pointer Metadata
• Parse Prometheus Exposition format in Rust using Pest
• Client-Side Server with Rust: A New Approach to UI Development
• [video] Andreas Monitzer - Bevy-ECS explained - Rust Vienna June 2023

Rust Walkthroughs

• Handling Rust enum variants with kinded crate
• Let's Build a Cargo Compatible Build Tool - Part 1
• Instrumenting Axum projects
• Rust Server Components
• Optimizing Rust Enum Debug-ing with Perfect Hashing
• Running a Bevy game in SvelteKit
• ESP32 Standard Library Embedded Rust: Timers

Miscellaneous

• Shuttle Launchpad #5: Our first foray into traits!
• [video] Rust API design: the curious case of Result
• [video] A Tour of Iced 0.10
• [video] 5 programs you can't compile with Rust
• [video] Rich Terminal Interfaces with Ratatui
• [video] Build a Cross Platform Mobile SDK in Rust

Crate of the Week

This week's crate is deep_causality, a hyper-geometric computational causality library.

Thanks to Marvin Hansen for the self-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.

• zerocopy - Install OpenSSF Scorecard and consider adopting its recommendations
• Ockam - Add icons to the menu items in Tauri system tray app 1
• Ockam - Improve docs of ockam completion clap command to specify how to use it
• Ockam - Remove unused Error enum members and avoid appearing of such members in the future 1
• Hyperswitch - Add Create Merchant and Create Merchant Key Store in a DB transaction
• Hyperswitch - Use proxy exclusion instead of a separate proxied client
• Hyperswitch - Schedule webhook for retry

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

Updates from the Rust Project

417 pull requests were merged in the last week

• WASI threads, implementation of wasm32-wasi-preview1-threads target
• set max_atomic_width for AVR to 16
• set max_atomic_width for sparc-unknown-linux-gnu to 32
• re-enable atomic loads and stores for all RISC-V targets
• account for Rc and Arc when suggesting to clone
• account for macros when suggesting a new let binding
• avoid invalid NaN lint machine-applicable suggestion in const context
• avoid wrong code suggesting for attribute macro
• change default panic handler message format
• parser: more friendly hints for handling async move in the 2015 edition
• coverage: consolidate FFI types into one module
• coverage: replace ExpressionOperandId with enum Operand
• detect trait upcasting through struct tail unsizing in new solver select
• don't ICE on higher ranked hidden types
• fix ICE failed to get layout for ReferencesError
• fix invalid slice coercion suggestion reported in turbofish
• fix suggestion spans for expr from macro expansions
• fix the span in the suggestion of remove question mark
• fix wrong span for trait selection failure error reporting
• expand, rename and improve incorrect_fn_null_checks lint
• improve invalid_reference_casting lint
• improve diagnostic for wrong borrow on binary operations
• improve spans for indexing expressions
• infer type in irrefutable slice patterns with fixed length as array
• interpret: fix alignment handling for Repeat expressions
• make Debug representations of [Lazy, Once]*[Cell, Lock] consistent with Mutex and RwLock
• make unconditional_recursion warning detect recursive drops
• make lint missing-copy-implementations honor negative Copy impls
• make test harness lint about unnnameable tests
• only consider places with the same local in each_borrow_involving_path
• only unpack tupled args in inliner if we expect args to be unpacked
• const validation: point at where we found a pointer but expected an integer
• optimize Iterator implementation for &mut impl Iterator + Sized
• perform OpaqueCast field projection on HIR, too
• remove constness from TraitPredicate
• resolve before canonicalization in new solver, ICE if unresolved
• resolve visibility paths as modules not as types
• reword confusable_idents lint
• rework upcasting confirmation to support upcasting to fewer projections in target bounds
• specify macro is invalid in certain contexts
• steal MIR for CTFE when possible
• strip unexpected debuginfo from libLLVM.so and librustc_driver.so when not requesting any debuginfo
• suggests turbofish in patterns
• add allocation to SMIR
• add missing rvalues to SMIR
• add trait decls to SMIR
• miri-script and cargo-miri cleanups
• miri-script: simplify flag computation a bit
• miri: fix error on dangling pointer inbounds offset
• miri: add some SB and TB tests
• miri: avoid infinite recursion for auto-fmt and auto-clippy
• miri: tree borrows: consider some retags as writes for the purpose of data races
• do not run ConstProp on mir_for_ctfe
• add a new compare_bytes intrinsic instead of calling memcmp directly
• some parser and AST cleanups
• convert builtin "global" late lints to run per module
• use parking lot's rwlock even without parallel-rustc
• parent_module_from_def_id does not need to be a query
• rustc_data_structures: Simplify base_n::push_str
• rustc_span: Hoist lookup sorted by words out of the loop
• cg_llvm: stop identifying ADTs in LLVM IR
• filter out short-lived LLVM diagnostics before they reach the rustc handler
• stabilize abi_thiscall
• impl SliceIndex<str> for (Bound<usize>, Bound<usize>)
• implement RefUnwindSafe for Backtrace
• implement Option::take_if
• unix/kernel_copy.rs: copy_file_range_candidate allows empty output files
• regex-automata: fix incorrect offsets reported by reverse inner optimization
• regex: fix memory usage regression for RegexSet with capture groups
• cargo: bail out an error when using cargo: in custom build script
• cargo: display crate version on timings graph
• cargo: don't attempt to read a token from stdin if a cmdline token is provided
• cargo: fix CVE-2023-38497 for master
• cargo: fix printing multiple warning messages for unused fields in registries table
• cargo: refactor: migrate to tracing
• rustfmt: fix: add parenthesis around .. closure if it's a method call receiver
• clippy: ptr_as_ptr: Take snippet instead of pretty printing type
• clippy: redundant_type_annotations: only pass certain def kinds to type_of
• clippy: unnecessary_mut_passed: don't lint in macro expansions
• clippy: unwrap_used: Do not lint unwrapping on ! or never-like enums
• clippy: alphabetically order arms in methods/mod.rs match
• clippy: fix suspicious_xor_used_as_pow.rs performance
• clippy: new lint ignored_unit_patterns
• clippy: new lints: impossible_comparisons and redundant_comparisons
• clippy: suppress question_mark warning if question_mark_used is not allowed
• rust-analyzer: allow match to matches assist to trigger on non-literal bool arms
• rust-analyzer: skip doc(hidden) default members
• rust-analyzer: don't provide generate_default_from_new when impl self ty is missing
• rust-analyzer: exclude non-identifier aliases from completion filtering text
• rust-analyzer: added remove unused imports assist
• rust-analyzer: fix unsized struct problems in mir eval
• rust-analyzer: don't provide add_missing_match_arms assist when upmapping match arm list failed
• rust-analyzer: remove unwraps from "Generate delegate trait"
• rust-analyzer: strip unused token ids from eager macro input token maps
• rust-analyzer: name change Import to Use in hir-def, add unused placeholder variants for UseId
• rust-analyzer: set the default status bar action to openLogs
• rust-analyzer: use the warning color when rust-analyzer is stopped

Rust Compiler Performance Triage

Overall a very positive last week, primarily due to an upgrade to LLVM 17 and some changes to lint execution. Memory usage is down 4-7% over the last week and wall times are down 3-5%.

Triage done by @simulacrum. Revision range: 828bdc2c..443c3161

2 Regressions, 7 Improvements, 2 Mixed; 2 of them in rollups 64 artifact comparisons made in total

Full report 7/22-8/1, Full report 8/1-8/8.

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

• No RFCs entered Final Comment Period this week.

Tracking Issues & PRs

• [disposition: merge] Specialize count for range iterators
• [disposition: merge] Accept additional user-defined classes in fenced code blocks
• [disposition: merge] Warn on inductive cycle in coherence leading to impls being considered not overlapping
• [disposition: close] Named format arguments can be used as positional
• [disposition: merge] Tracking Issue for const_collections_with_hasher
• [disposition: merge] Document soundness of Integer -> Pointer -> Integer conversions in const contexts.
• [disposition: merge] Allow explicit #[repr(Rust)]
• [disposition: merge] Tracking issue for thread local Cell methods
• [disposition: merge] Implement From\<OwnedFd/Handle> for ChildStdin/out/err object

New and Updated RFCs

• [new] CPU feature detection in core

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 2023-08-09 - 2023-09-06 🦀

Virtual

• 2023-08-09 | Virtual (New York, NY, US) | Rust NYC
  • Helping Rust Developers See Data Dependencies in the IDE
• 2023-08-10 | Virtual (Berlin, DE) | Berlin.rs
  • Rust and Tell - August Edition
• 2023-08-10 | Virtual (Charlottesville, NC, US) | Charlottesville Rust Meetup
  • Crafting Interpreters in Rust Collaboratively
• 2023-08-10 | Virtual (Nuremberg, DE) | Rust Nuremberg
  • Rust Nürnberg online
• 2023-08-15 | Virtual (Berlin, DE) | OpenTechSchool Berlin
  • Rust Hack and Learn
• 2023-08-15 | Virtual (Washington, DC, US) | Rust DC
  • Mid-month Rustful
• 2023-08-16 | Virtual (Vancouver, BC, CA) | Vancouver Rust
  • Rust Study/Hack/Hang-out
• 2023-08-17 | Virtual (Linz, AT) | Rust Linz
  • Rust Meetup Linz - 32nd Edition
• 2023-08-17 | Virtual (Stuttgart, DE) | Rust Community Stuttgart
  • Rust Hack and Learn
• 2023-08-22 | Virtual (Dublin, IE) | Rust Dublin
  • Rust, Serverless and AWS
• 2023-09-05 | Virtual (Buffalo, NY, US) | Buffalo Rust Meetup
  • Buffalo Rust User Group, First Tuesdays
• 2023-09-05 | Virtual (Munich, DE) | Rust Munich
  • Rust Munich 2023 / 4 - hybrid
• 2023-09-06 | Virtual (Indianapolis, IN, US) | Indy Rust
  • Indy.rs - with Social Distancing

Asia

• 2023-08-09 | Kuala Lumpur, MY | Rust Malaysia
  • Rust Malaysia Meetup August 2023
• 2023-08-10 | Tokyo, JP | Tokyo Rust Meetup
  • Bring Your Laptop: The Great Oxidation Event

Europe

• 2023-08-17 | Reading, UK | Reading Rust Workshop
  • Reading Rust Meetup at Browns
• 2023-08-19 | Augsburg, DE | Rust Rhein-Main
  • Rust Frontend Workshop (Yew + WebAssembly + Axum)
• 2023-08-22 | Helsinki, FI | Finland Rust Meetup
  • Helsink Rustaceans First Gathering
• 2023-08-23 | London, UK | Rust London User Group
  • LDN Talks Aug 2023: Rust London x RNL (The next Frontier in App Development)
• 2023-08-24 | Aarhus, DK | Rust Aarhus
  • Rust Aarhus Hack and Learn at Trifork
• 2023-08-31 | Augsburg, DE | Rust Meetup Augsburg
  • Augsburg Rust Meetup #2
• 2023-09-05 | Munich, DE + Virtual | Rust Munich
  • Rust Munich 2023 / 4 - hybrid

North America

• 2023-08-10 | Mountain View, CA, US | Mountain View Rust Meetup
  • Rust Meetup at Hacker Dojo
• 2023-08-10 | Lehi, UT, US | Utah Rust
  • Building a simplified JVM in Rust
• 2023-08-15 | San Francisco, CA, US | San Francisco Rust Study Group
  • Rust Hacking in Person
• 2023-08-15 | Seattle, WA, US | Seattle Rust User Group Meetup
  • Seattle Rust User Group - August Meetup
• 2023-08-16 | Cambridge, MA, US | Boston Rust Meetup
  • Alewife Rust Lunch
• 2023-08-16 | Copenhagen, DK | Copenhagen Rust Community
  • Rust metup #39 sponsored by Fermyon
• 2023-08-17 | Nashville, TN, US | Seattle Rust User Group Meetup
  • Rust goes where it pleases. Rust on the web and embedded
• 2023-08-23 | Austin, TX, US | Rust ATX
  • Rust Lunch - Fareground
• 2023-08-24 | Mountain View, CA, US | Mountain View Rust Meetup
  • Rust Meetup at Hacker Dojo
• 2023-09-06 | Bellevue, WA, US | The Linux Foundation
  • Rust Global

Oceania

• 2023-08-09 | Perth, WA, AU | Rust Perth
  • August Meetup
• 2023-08-15 | Melbourne, VIC, AU | Rust Melbourne
  • (Hybrid - in person & online) August 2023 Rust Melbourne 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

Claiming Rust won't help you because you're doing so many unsafe things is like claiming protective gear won't help you because you're handling so many dangerous substances.

– llogiq on twitter

llogiq feels very smug about his self-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