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

Foundation

• Guest Blog: Attending CISA’s Open Source Software Security Summit

Newsletters

• This Month in Rust OSDev: March 2024

Project/Tooling Updates

• lilos v1.0 released
• medium-to-markdown v0.1.1 : Convert your medium blogs easily into markdown files
• Fluvio v0.11.6 release and project updates
• venndb 0.4.0 - custom validators
• Tantivy 0.22: Performance improvements, new aggregations and stability fixes
• Announcing r3bl_terminal_async - build async interactive CLIs in Rust
• [video] Demo + architecture overview of Ferrostar, a cross-platform turn-by-turn navigation SDK with a Rust core

Observations/Thoughts

• The Rust Calling Convention We Deserve
• Sized, DynSized, and Unsized
• Coroutines and effects
• Porting a cross-platform GUI application to Rust
• Adventures In Rust: Bringing Exchange Support To Thunderbird

Rust Walkthroughs

• Why SQLite Performance Tuning made Bencher 1200x Faster
• drop, the destructor of Rust structs
• Building with AWS S3 using Rust
• Rust tokio task cancellation patterns
• [video] Build with Naz - Published crate r3bl_terminal_async for building async interactive CLIs in Rust
• [video] Trent Billington - Bevy ECS - Power tool for data oriented applications
• [video] Building a procedural art generator
• [audio] Isograph with Robert Balicki

Research

• A Study of Undefined Behavior Across Foreign Function Boundaries in Rust Libraries
• Rust Digger: Does size matter? The biggest crate is 450MB; More than 100 crates are over 50MB

Miscellaneous

• GitHub Sponsor Rust developer David Tolnay
• Learn how to write TCP servers using Rust's std::net module
• RustFest Zürich 🇨 Talks announced

Crate of the Week

This week's crate is scandir, a high-performance file tree scanner.

Thanks to Marty B. for the self-suggestion!

Please submit your suggestions and votes for next week!

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 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.

• awesome-alternatives-in-rust - Add dqy alternative to dig
• fluvio - When a topic is deleted, connected clients should have their connection closed
• fluvio - MQTT Connector: Prefix auto generated Client ID to prevent connection drops
• fluvio - Remove localhost from fluvio in favor of 127.0.0.1

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

CFP - Speakers

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.

• RustConf 2024 | Closes 2024-04-25 | Montreal, Canada | Event date: 2024-09-10
• RustLab 2024 | Closes 2024-05-01 | Florence, Italy | Event date: 2024-11-09 - 2024-11-11
• EuroRust 2024| Closes 2024-06-03 | Vienna, Austria & online | Event date: 2024-10-10
• Scientific Computing in Rust 2024| Closes 2024-06-14 | online | Event date: 2024-07-17 - 2024-07-19
• Conf42 Rustlang 2024 | Closes 2024-07-22 | online | Event date: 2024-08-22

If you are an event organizer hoping to expand the reach of your event, please submit a link to the submission website through a PR to TWiR.

Updates from the Rust Project

432 pull requests were merged in the last week

• add simple async drop glue generation
• llvm backend: Prevent creating the same Instance::mono multiple times
• static_mut_refs: use raw pointers to remove the remaining FIXME
• add a lower bound check to unicode-table-generator output
• add an opt-in to store incoming edges in VecGraph + misc
• add llvm-bitcode-linker to build manifest
• allow workproducts without object files
• at debuginfo=0, don't inline debuginfo when inlining
• correctly change type when adding adjustments on top of NeverToAny
• coverage: branch coverage tests for lazy boolean operators
• coverage: prepare for improved branch coverage
• delay interning errors to after validation
• delay span bug when Self kw resolves to DefKind::{Mod,Trait}
• don't ICE for kind mismatches during error rendering
• don't ascend into parent bodies when collecting stmts for possible return suggestion
• don't error on subtyping of equal types
• don't inline integer literals when they overflow - new attempt
• don't repeatedly duplicate TAIT lifetimes for each subsequently nested TAIT
• fix ICE in eval_body_using_ecx
• fix ICE when there is a non-Unicode entry in the incremental crate directory
• fix capturing duplicated lifetimes via parent in precise_captures (impl use<'...>)
• fix normalizing in different ParamEnvs with the same InferCtxt
• fix trait solver overflow with non_local_definitions lint
• flip spans for precise capturing syntax not capturing a ty/const param, and for implicit captures of lifetime params
• give a name to each distinct manipulation of pretty-printer FixupContext
• ignore -C strip on MSVC
• implement Modified Condition/Decision Coverage
• implement PROBLEMATIC_CONSTS generalization
• implement syntax for impl Trait to specify its captures explicitly (feature(precise_capturing))
• improve ICE message for forbidden dep-graph reads
• interpret: pass MemoryKind to adjust_alloc_base_pointer
• interpret: pass MemoryKind to before_memory_deallocation
• interpret: use ScalarInt for bin-ops; avoid PartialOrd for ScalarInt
• introduce perma-unstable wasm-c-abi flag
• let inherent associated types constrain opaque types during projection
• make suggest_deref_closure_return more idiomatic/easier to understand
• make thir_tree and thir_flat into hooks
• make the comments for ReturnDest variants doc comments
• match ergonomics 2024: Implement eat-one-layer
• match ergonomics 2024: mut doesn't reset binding mode
• match hyphen in multi-revision comment matchers
• opaque types have no namespace
• outline default query and hook provider function implementations
• prefer identity equality over equating types during coercion
• print note with closure signature on type mismatch
• properly handle emojis as literal prefix in macros
• remove default_hidden_visibility: false from wasm targets
• remove uneeded clones now that TrustedStep implies Copy
• silence some follow-up errors on trait impls in case the trait has conflicting or otherwise incoherent impls
• simplify shallow resolver to just fold ty/consts
• stop taking ParamTy/ParamConst/EarlyParamRegion/AliasTy by ref
• subtype predicates only exist on inference types, so we can allow them to register opaque types within them
• tell LLVM Vec::len is invariant across growth
• use raw-dylib for Windows synchronization functions
• refactor clippy in bootstrap
• when suggesting RUST_BACKTRACE=1, add a special note for Miri's env var isolation
• miri: data_race: make the release/acquire API more clear
• miri: no_std works on Windows now
• miri: add localtime_r shim
• miri: address reuse improvements and fixes
• miri: deadlock: show backtrace for all threads
• miri: directly call handle_alloc_error
• miri: implement support for __rust_alloc_error_handler
• miri: make realloc with a size of zero fail
• miri: move read_byte_slice to general helpers file, next to read_c_str
• miri: threads: keep track of why we are blocked, and sanity-check that when waking up
• Box::into_raw: make Miri understand that this is a box-to-raw cast
• PatRangeBoundary::compare_with: also add a fast-path for signed integers
• codegen ZSTs without an allocation
• stabilize Wasm target features that are in phase 4 and 5
• stabilize const_io_structs
• stabilize checking of cfgs at compile-time: --check-cfg option
• stabilize generic NonZero
• make checked ops emit unchecked LLVM operations where feasible
• improve std::fs::Metadata Debug representation
• fix negating f16 and f128 constants
• force exhaustion in iter::ArrayChunks::into_remainder
• checked_ilog: improve performance
• add an intrinsic for ptr::from_raw_parts(_mut)
• fix: make str::from_raw_parts_mut mut
• use queue-based RwLock on more platforms
• add support for Arm64EC to the standard library
• codegen_gcc: fix PassMode::Indirect with params
• codegen_gcc: fix check for main function already declared
• codegen_gcc: fix panic when calling get_fn for a variable
• codegen_gcc: fix passing custom CG_RUSTFLAGS when building sysroot
• codegen_gcc: implement more type kinds
• cargo install: including Locking message
• cargo resolver: add default Edition2024 to resolver v3
• cargo resolver: add v3 resolver for MSRV-aware resolving
• cargo credential: trim newlines in tokens from stdin
• cargo msrv: error, rather than panic, on rust-version 'x'
• cargo msrv: put MSRV-aware resolver behind a config
• cargo toml: don't crash on parse errors that point to multi-byte character
• cargo toml: disallow source-less dependencies
• cargo toml: error on [project] in Edition 2024
• cargo toml: report _fied variants (e.g. dev_dependencies) as deprecated
• cargo: fix 'cargo build' fails when list_files() with gix is triggered
• rustdoc: always display stability version even if it's the same as the containing item
• rustdoc: fix copy path button
• rustdoc: support type '/' to search
• rustdoc-search: fix description on aliases in results
• rustdoc-search: single result for items with multiple paths
• clippy: threadlocal_initializer_can_be_made_const will not trigger for unreachable initializers
• clippy: arithmetic_side_effects fix false negative on +=
• clippy: ptr_as_ptr: fix duplicate diagnostics
• clippy: emit the needless_pass_by_ref_mut lint on self arguments as well
• clippy: fix is_test_module_or_function
• clippy: reduce single_char_pattern to only lint on ascii chars
• clippy: rework interior mutability detection
• clippy: the multiple_unsafe_ops_per_block test needs asm!
• rust-analyzer: cargo script mvp
• rust-analyzer: add convert From to TryFrom assist
• rust-analyzer: allow rust files to be used linkedProjects
• rust-analyzer: VFS should not walk circular symlinks
• rust-analyzer: handle escaped chars in doc comments
• rust-analyzer: replace Just the variable name in Unused Variable Diagnostic Fix
• rust-analyzer: implement BeginPanic handling in const eval
• rust-analyzer: make test harness arguments configurable and not --nocapture
• rust-analyzer: render matched macro arm on hover of macro calls
• rust-analyzer: try to generate more meaningful names in json converter

Rust Compiler Performance Triage

A week dominated by small mixed changes to perf with improvements slightly outweighing regressions. There were no pure regressions, and many of the mixed perf results were deemed worth it for their potential improvements to runtime performance through further optimization from LLVM.

Triage done by @rylev. Revision range: ccfcd950..a77f76e2

Summary:

0 Regressions, 5 Improvements, 6 Mixed; 2 of them in rollups 62 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:

• 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] experimental project goal program for 2024 H2

Tracking Issues & PRs

Rust

• [disposition: merge] Tracking Issue for std::path::absolute
• [disposition: merge] Tracking Issue for convenience methods on NonNull
• [disposition: merge] Inline more svg images into CSS
• [disposition: merge] Edition 2024: Make ! fall back to !
• [disposition: merge] static_mut_refs: Should the lint cover hidden references?

Cargo

• [disposition: merge] fix(toml): Warn, rather than fail publish, if a target is excluded

New and Updated RFCs

• [new] experimental project goal program for 2024 H2

Upcoming Events

Rusty Events between 2024-04-24 - 2024-05-22 🦀

Virtual

• 2024-04-24 | Virtual + In Person (Prague, CZ) | Rust Czech Republic
  • #2: Making Safe Rust Safer (Pavel Šimerda)
• 2024-04-25 | Virtual (Berlin, DE) | OpenTechSchool Berlin + Rust Berlin
  • Rust Hack and Learn | Mirror: Rust Hack n Learn Meetup
• 2024-04-30 | Virtual (Dallas, TX, US) | Dallas Rust
  • Last Tuesday
• 2024-05-01 | Virtual (Cardiff, UK) | Rust and C++ Cardiff
  • Rust for Rustaceans Book Club: Chapter 5 - Project Structure
• 2024-05-01 | Virtual (Indianapolis, IN, US) | Indy Rust
  • Indy.rs - with Social Distancing
• 2024-05-02 | Virtual (Charlottesville, NC, US) | Charlottesville Rust Meetup
  • Crafting Interpreters in Rust Collaboratively
• 2024-05-07 | Virtual (Buffalo, NY) | Buffalo Rust Meetup
  • Buffalo Rust User Group
• 2024-05-09 | Virtual (Berlin, DE) | OpenTechSchool Berlin + Rust Berlin
  • Rust Hack and Learn | Mirror: Rust Hack n Learn Meetup
• 2024-05-09 | Virtual (Israel) | Rust in Israel
  • Rust at Microsoft, Tel Aviv - Are we embedded yet?
• 2024-05-09 | Virtual (Nuremberg/Nürnberg, DE) | Rust Nuremberg
  • Rust Nürnberg online
• 2024-05-14 | Virtual (Dallas, TX, US) | Dallas Rust
  • Second Tuesday
• 2024-05-14 | Virtual (Halifax, NS, CA) | Rust Halifax
  • Rust&Tell - Halifax
• 2024-05-14 | Virtual + In-Person (München/Munich, DE) | Rust Munich
  • Rust Munich 2024 / 1 - hybrid (Rescheduled)
• 2024-05-15 | Virtual (Vancouver, BC, CA) | Vancouver Rust
  • Rust Study/Hack/Hang-out
• 2024-05-16 | Virtual (Charlottesville, VA, US) | Charlottesville Rust Meetup
  • Crafting Interpreters in Rust Collaboratively
• 2024-05-21 | Virtual (Washington, DC, US) | Rust DC
  • Mid-month Rustful—forensic parsing via Artemis

Africa

• 2024-05-04 | Kampala, UG | Rust Circle Kampala
  • Rust Circle Meetup

Asia

• 2024-05-11 | Bangalore, IN | Rust Bangalore
  • May 2024 Rustacean meetup

Europe

• 2024-04-24 | Virtual + In Person (Prague, CZ) | Rust Czech Republic
  • #2: Making Safe Rust Safer (Pavel Šimerda)
• 2024-04-25 | Aarhus, DK | Rust Aarhus
  • Talk Night at MFT Energy
• 2024-04-25 | Berlin, DE | Rust Berlin
  • Rust and Tell - TBD
• 2024-04-25 | København/Copenhagen, DK | Copenhagen Rust Community
  • Rust meetup #46 sponsored by Nine A/S
• 2024-04-25 | Vienna, AT | Rust Vienna
  • Rust Vienna x Python User Group - April
• 2024-04-27 | Basel, CH | Rust Basel
  • Fullstack Rust - Workshop #2 (Register by 23 April)
• 2024-04-27 | Stockholm, SE | Stockholm Rust
  • Ferris' Fika Forum #2
• 2024-04-30 | Budapest, HU | Budapest Rust Meetup Group
  • Rust Meetup Budapest 2
• 2024-04-30 | Salzburg, AT | Rust Salzburg
  • [Rust Salzburg meetup]: 6:30pm - CCC Salzburg, 1. OG, ArgeKultur, Ulrike-Gschwandtner-Straße 5, 5020 Salzburg
• 2024-05-01 | Köln/Cologne, DE | Rust Cologne
  • This Month in Rust, May
• 2024-05-01 | Utrecht, NL | NL-RSE Community
  • NL-RSE RUST meetup
• 2024-05-06 | Delft, NL | GOSIM
  • GOSIM Europe 2024
• 2024-05-07 & 2024-05-08 | Delft, NL | RustNL
  • RustNL 2024
• 2024-05-08 | Cambridge, UK | Cambridge Rust Meetup
  • Monthly Rust Meetup
• 2024-05-09 | Gdańsk, PL | Rust Gdansk
  • Rust Gdansk Meetup #2
• 2024-05-14 | Virtual + In-Person (München/Munich, DE) | Rust Munich
  • Rust Munich 2024 / 1 - hybrid (Rescheduled)
• 2024-05-14 | Prague, CZ | Rust Prague
  • Rust Meetup Prague (May 2024)
• 2024-05-21 | Aarhus, DK | Rust Aarhus
  • Hack Night
• 2024-05-21 | Zurich, CH | Rust Zurich
  • Save the date - Mai Meetup

North America

• 2024-04-24 | Austin, TX, US | Rust ATX
  • Rust Lunch - Fareground
• 2024-04-25 | Nashville, TN, US | Music City Rust Developers
  • Music City Rust Developers - Async Rust on Embedded
• 2024-04-26 | Boston, MA, US | Boston Rust Meetup
  • North End Rust Lunch, Apr 26
• 2024-05-04 | Cambridge, MA, US | Boston Rust Meetup
  • Kendall Rust Lunch, May 4
• 2024-05-09 | Spokane, WA, US | Spokane Rust
  • Monthly Meetup: Topic TBD!
• 2024-05-12 | Brookline, MA, US | Boston Rust Meetup
  • Coolidge Corner Brookline Rust Lunch, May 12
• 2024-05-16 | Seattle, WA, US | Seattle Rust User Group
  • Seattle Rust User Group Meetup
• 2024-05-20 | Somerville, MA, US | Boston Rust Meetup
  • Ball Square Rust Lunch, May 20
• 2024-05-21 | San Francisco, CA, US | San Francisco Rust Study Group
  • Rust Hacking in Person
• 2024-05-22 | Austin, TX, US | Rust ATX
  • Rust Lunch - Fareground

Oceania

• 2024-04-30 | Auckland, NZ | Rust AKL
  • Rust AKL: Why Rust? Convince Me!
• 2024-04-30 | Canberra, ACT, AU | Canberra Rust User Group
  • CRUG April Meetup: Generics and Traits

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 learning curve for Rust is relatively steep compared to other languages, but once you climb it you'll never look down.

– BD103 on Mastodon

Thanks to BD103 for the 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.

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Discuss on r/rust