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

• 2024 Leadership Council Survey
• Embedded Working Group Community Micro Survey

Foundation

• What's in Store at RustConf 2024

Project/Tooling Updates

• git-cliff 2.5.0 is released!
• Ferrocene 24.08.0 now available!
• Go wild: Wildcard support in Rules and a new open-source wildcard crate
• Why am I writing a Rust compiler in C?
• Current zlib-rs performance
• Bon builder generator 2.0 release 🎉
• Meilisearch 1.10

Observations/Thoughts

• Rust dylib rabbit holes
• I sped up serde_json strings by 20%
• Using StringView / German Style Strings to Make Queries Faster: Part 1 - Reading Parquet
• Rust as My First Language
• Doctests - How were they improved?
• MiniJinja: Learnings from Building a Template Engine in Rust
• Standards for use of unsafe Rust in the kernel
• Rust vs C++: A Real-World Perspective (interview with Tyler Weaver)
• A Piece of UNIX History in Rust
• Why Amazon, Cloudflare and Discord are building servers in Rust but you should probably not

Rust Walkthroughs

• Let the API protect you
• Packaging a Rust Program for Fedora
• Building a Bevy Plugin for Rolling Dice
• [video] Implementing a Lox interpreter in Rust
• [video] Command line tools: Implementing wc in Rust
• [video] Explore Linux TTY, process, signals w/ Rust - Part 1/3 (background info)

Research

• On the Impact of Memory Safety on Fast Network I/O

Miscellaneous

• Can DARPA’s TRACTOR Pull C to Rust for Memory-Safe Overhaul?
• Crafting a Blockchain in Go and Rust: A Comparative Journey — Private keys, Public Keys and Signatures [Part 1]
• [video] A Multiplatform Mobile Navigation SDK with Rust at the Core

Crate of the Week

This week's crate is wtx, a batteries-included web application framework.

Thanks to Caio 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.

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

429 pull requests were merged in the last week

• add Trusty OS as tier 3 target
• CFI: erase regions when projecting ADT to its transparent non-1zst field
• add missing module flags for CFI and KCFI sanitizers
• repr_transparent_external_private_fields: special-case some std types
• add a special case for CStr/CString in the improper_ctypes lint
• avoid extra cast()s after CStr::as_ptr()
• const checking: properly compute the set of transient locals
• ctfe: make CompileTimeInterpCx type alias public
• detect * operator on !Sized expression
• do not ICE on non-ADT rcvr type when looking for crate version collision
• don't consider locals to shadow inner items' generics
• don't generate functions with the rustc_intrinsic_must_be_overridden attribute
• don't trigger refinement lint if predicates reference errors
• fix extern crates not being hidden with doc(hidden)
• fix handling of macro arguments within the dropping_copy_types lint
• implement -Z embed-source (DWARFv5 source code embedding extension)
• improve diagnostic-related lints: untranslatable_diagnostic & diagnostic_outside_of_impl
• interpret: immTy: tighten sanity checks in offset logic
• lint on tail expr drop order change in Edition 2024
• llvm-wrapper: adapt for LLVM 20 API changes
• make ArgAbi::make_indirect_force more specific
• make writes_through_immutable_pointer a hard error
• more work on zstd compression
• mv build_reduced_graph_for_external_crate_res into Resolver
• pal/hermit: correctly round up microseconds in Thread::sleep
• panicking: improve hint for Miri's RUST_BACKTRACE behavior
• point at explicit 'static obligations on a trait
• pretty-print own args of existential projections (dyn-Trait w/ GAT constraints)
• print the generic parameter along with the variance in dumps
• remove invalid TyCompat relation for effects
• safe transmute: gracefully bubble-up layout errors
• skip updating when external binding is existed
• use assert_unsafe_precondition! in AsciiChar::digit_unchecked
• use a LocalDefId in ResolvedArg
• use old ctx if has same expand environment during decode span
• use subtyping for UnsafeFnPointer coercion, too
• miri: provenance_gc: fix comment
• miri: readdir_r shim: assume FreeBSD v12+
• miri: avoid extra copy by using retain_mut and moving the deletion into the closure
• miri: disable tree traversal optimization that is wrong due to lazy nodes
• miri: epoll: add a EINVAL case
• miri: epoll: handle edge case for epoll_ctl
• miri: fix a misleading comment in tests/pass/tree_borrows/tree-borrows.rs
• miri: fix calling pipe, pipe2, socketpair with a pointer-to-array
• miri: implement SHA256 SIMD intrinsics on x86
• miri: make Tree Borrows Provenance GC no longer produce stack overflows
• miri weak memory emulation: put previous value into initial store buffer
• stabilize opaque type precise capturing (RFC 3617)
• stabilize const_fn_floating_point_arithmetic
• stabilize iter::repeat_n
• stabilize feature char_indices_offset
• implement debug_more_non_exhaustive
• add Box::as_ptr and Box::as_mut_ptr methods
• add const_cell_into_inner to OnceCell
• add f16 and f128 inline ASM support for aarch64
• add a precondition check for Layout::from_size_align_unchecked
• add implementations for unbounded_shl/unbounded_shr
• change neutral element of <fNN as iter::Sum> to neg_zero
• library: move unstable API of new_uninit to new features
• fix thread::sleep Duration-handling for ESP-IDF
• fix: fs::remove_dir_all: treat internal ENOENT as success
• put Pin::as_deref_mut in impl Pin<Ptr> / rearrange Pin methods
• implement ptr::fn_addr_eq
• hashbrown: deprecate the raw entry API in favor of HashTable
• hashbrown: rework the Entry API
• cargo: mdman: Normalize newlines when rendering options
• cargo resolve: Dont show locking workspace members
• cargo: be more permissive while packaging unpublishable crates
• cargo: add matches_prerelease semantic
• cargo: -Cmetadata includes whether extra rustflags is same as host
• cargo: doctest respects Cargo's color options
• cargo: limiting pre-release match semantics to use only on OptVersionReq::Req
• cargo: log details of failure if no errors were seen
• cargo: more helpful missing feature error message
• rustdoc-search: use tighter json for names and parents
• rustdoc: animate the :target highlight
• rustdoc: show exact case-sensitive matches first
• rustdoc: Generate source link on impl associated types
• clippy: declare_interior_mutable_const: Ignore pointer types
• clippy: add new too_long_first_doc_paragraph first paragraph lint
• clippy: add new lint: used_underscore_items
• clippy: check std::panic::panic_any in panic lint
• clippy: diverging subexpression lint should not fire on todo!()
• clippy: fix manual_range_patterns case with one element at OR
• clippy: fix confusing message in double_must_use lint
• clippy: fix suggestion unnecessary_lazy_eval
• clippy: ignore underscore-prefixed args for needless_pass_by_value lint
• clippy: rewrite empty_line_after_doc_comments and empty_line_after_outer_attr, move them from nursery to suspicious
• clippy: start removing snippet_opt in favor of get_source_text
• rust-analyzer: add new assist toggle_macro_delimiter
• rust-analyzer: allow declaring cfg groups in rust-project.json, to help sharing common cfgs
• rust-analyzer: add workspace level config to ratoml
• rust-analyzer: always show error lifetime arguments as '_
• rust-analyzer: don't enable the search fast path for short associated functions when a search scope is set
• rust-analyzer: expand proc-macros in workspace root, not package root
• rust-analyzer: fix "Unwrap block" assist with block modifiers
• rust-analyzer: fix Return Type Syntax to include .. (i.e. method(..) and not method()) as specified in the RFC
• rust-analyzer: fix metadata retrying eating original errors
• rust-analyzer: fix trait method completions not acknowledging Deref impls
• rust-analyzer: improve proc-macro panic message and workspace loading failure diagnostic
• rust-analyzer: run flycheck without rev_deps when target is specified
• rust-analyzer: rust-analyzer should watch build files from rust-project.json
• rust-analyzer: wrong Self: Sized predicate for trait assoc items
• rust-analyzer: wrong Sized predicate for generic_predicates_for_param
• rust-analyzer: implement floating point casts in const eval
• rust-analyzer: perf: speed up search for short associated functions, especially very common identifiers such as new
• rust-analyzer: remove the ability to configure the user config path

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:

• 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

• [disposition: merge] crates.io: Remove dev-dependencies from the index
• [disposition: merge] Mergeable rustdoc cross-crate info
• [disposition: merge] Guard Patterns

Tracking Issues & PRs

Rust

• [disposition: merge] Proposal: stabilize const_refs_to_static
• [disposition: merge] Check WF of source type's signature on fn pointer cast
• [disposition: merge] rustdoc: add header map to the table of contents
• [disposition: merge] doc: Make block of inline Deref methods foldable

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 RFCs 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] #[derive(Default)] on enum variants with fields
• [new] [RFC] Default field values
• [new] Simplify lightweight clones, including into closures and async blocks

Upcoming Events

Rusty Events between 2024-08-28 - 2024-09-25 🦀

Virtual

• 2024-08-28 | Virtual (Tel Aviv, IL) | Code Mavens
  • Command Line Tools: Implementing wc in Rust (English, Virtual)
• 2024-08-29 | Virtual (Berlin, DE) | OpenTechSchool Berlin + Rust Berlin
  • Rust Hack and Learn | Mirror: Rust Hack n Learn Meetup
• 2024-08-29 | Virtual (Tel Aviv, IL) | Code Mavens
  • Rust Source Code Reading: The thousands crate (English)
• 2024-09-03 | Virtual (Buffalo, NY, US) | Buffalo Rust Meetup
  • Buffalo Rust User Group
• 2024-09-04 | Virtual (Indianapolis, IN, US) | Indy Rust
  • Indy.rs - Typestate Pattern in Rust: With a Strict Builder Example
• 2024-09-05 | Virtual | LambdaClass
  • Meetup Rust Septiembre [Spanish]
• 2024-09-05 | Virtual (Charlottesville, NC, US) | Charlottesville Rust Meetup
  • Crafting Interpreters in Rust Collaboratively
• 2024-09-05 | Virtual (Nürnberg, DE) | Rust Nuremberg
  • Rust Nürnberg online
• 2024-09-10 | Virtual (Dallas, TX, US) | Dallas Rust
  • Second Tuesday
• 2024-09-10 - 2024-09-13 | Hybrid: Virtual and In-Person (Montreal, QC, CA) | Rust Conf
  • Rust Conf 2024
• 2024-09-12 | Virtual (Berlin, DE) | OpenTechSchool Berlin + Rust Berlin
  • Rust Hack and Learn | Mirror: Rust Hack n Learn Meetup
• 2024-09-12 | Virtual (Rotterdam, NL) | Bevy Game Development
  • Bevy Meetup #6
• 2024-09-16 | Virtual | Women in Rust
  • 👋 Community Catch Up
• 2024-09-17 | Virtual (Washington, DC, US) | Rust DC
  • Mid-month Rustful
• 2024-09-18 | Virtual and In-Person (Vancouver, BC, CA) | Vancouver Rust
  • Cells
• 2024-09-18 - 2024-09-20 | Hybrid - Virtual and In-Person (Vienna, AT) | Linux Plumbers Conference
  • Rust Microconference in LPC 2024
• 2024-09-19 | Virtual (Charlottesville, NC, US) | Charlottesville Rust Meetup
  • Crafting Interpreters in Rust Collaboratively
• 2024-09-19 | Virtual and In-Person (Seattle, WA, US) | Seattle Rust User Group
  • September Meetup
• 2024-09-24 | Virtual (Dallas, TX, US) | Dallas Rust
  • Last Tuesday

Africa

• 2024-09-06 | Kampala, UG | Rust Circle Kampala
  • Rust Circle Meetup

Asia

• 2024-09-09 | Ramat Gan, IL | Coralogix
  • Rust as Scale
• 2024-09-14 | Bangalore, IN | Rust Bangalore
  • September 2024 Rustacean meetup

Europe

• 2024-08-28 | Frankfurt (Main), DE | Rust Rhein Main
  • Rust Frankfurt WebAssembly
• 2024-08-29 | Berlin, DE | OpenTechSchool Berlin + Rust Berlin
  • Rust and Tell - The social Beergarden.
• 2024-08-29 | Copenhagen, DK | Copenhagen Rust Community
  • Rust meetup #50 sponsored by Adapt Agency
• 2024-09-04 | Oxford, UK | Oxfrod Rust Meetup Group
  • More Rust - Generics, constraints, safety.
• 2024-09-11 | Reading, UK | Reading Rust Workshop
  • Reading Rust Meetup
• 2024-09-17 | Leipzig, DE | Rust - Modern Systems Programming in Leipzig
  • Topic TBD
• 2024-09-17 | Trondheim, NO | Rust Trondheim
  • Making AI-models perform tasks, in Rust!
• 2024-09-18 | Moravia, CZ | Rust Moravia
  • Rust Moravia Meetup (September 2024)
• 2024-09-18 | Vienna, AT + Virtual | Linux Plumbers Conference
  • Rust Microconference in LPC 2024 (Sep 18-20)
• 2024-09-23 | Bratislava, SK | Bratislava Rust Meetup Group
  • Rust Meetup by Sonalake #6

North America

• 2024-08-28 | Austin, TX, US | Rust ATX
  • Rust Lunch - Fareground
• 2024-08-29 | Nashville, TN, US | Music City Rust Developers
  • Music City Rust Developers : placeholder
• 2024-08-29 | Chicago, IL, US | Deep Dish Rust
  • Rust Hack Night/Happy Hour
• 2024-08-31 | Cambridge, MA, US | Boston Rust Meetup
  • Central Cambridge Rust Lunch, Aug 31
• 2024-09-05 | Mountain View, CA, US | Mountain View Rust Meetup
  • Rust Meetup at Hacker Dojo
• 2024-09-05 | Portland, OR, US | PDX Rust
  • PDX Rust September!
• 2024-09-05 | St. Louis, MO, US | STL Rust
  • Lifetimes
• 2024-09-07 | Longview, TX, US | Longview Code and Coffee
  • Longview Code and Coffee
• 2024-09-08 | Cambridge, MA, US | Boston Rust Meetup
  • Northeastern Rust Lunch, Sep 8
• 2024-09-10 - 2024-09-13 | Hybrid: Virtual and In-Person (Montreal, QC, CA) | Rust Conf
  • Rust Conf 2024
• 2024-09-11 | Boulder, CO, US | Boulder Rust Meetup
  • Boulder Elixir Meetup
• 2024-09-16 | Cambridge, MA, US | Boston Rust Meetup
  • Somerville Union Square Rust Lunch, Sep 16
• 2024-09-17 | San Francisco, CA, US | San Francisco Rust Study Group
  • Rust Hacking in Person
• 2024-09-18 | Virtual and In-Person (Vancouver, BC, CA) | Vancouver Rust
  • Cells
• 2024-09-19 | Virtual and In-Person (Seattle, WA, US) | Seattle Rust User Group
  • September Meetup
• 2024-09-21 | Longview, TX, US | Longview Code and Coffee
  • Longview Code and Coffee
• 2024-09-24 | Detroit, MI, US | Detroit Rust
  • Rust Community Meetup - Ferndale
• 2024-09-25 | Austin, TX, US | Rust ATX
  • Rust Lunch - Fareground

Oceania

• 2024-08-28 | Sydney, NSW, AU | Rust Sydney
  • Stuff ⚡ And Crabs 🦀

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

... opaque number sequences (\<GitHub> "issue numbers") are not very informative about what is behind that pointer, and pretending they are is harmful. People could provide, instead, actual reasons for things, which do not require dereferencing random pointers, which thrashes cache.

– Jubilee on rust-internals

Thanks to Anton Fetisov 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