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

• API token scopes for crates.io
• Updating Rust's Linux musl targets

Newsletters

• Rust Magazine: Issue 3

Observations/Thoughts

• A guide to test parametrization in Rust
• Iterator, Generator
• Breaking semver in Rust by adding a private type, or by adding an import
• Ask not what the compiler can do for you

Rust Walkthroughs

• How We Built Our Own Time-Tracking Algorithm for a Rust app
• ESP32 Embedded Rust at the HAL: UART Serial Communication
• Build a non-binary tree that is thread safe using Rust
• Coherence in Rust (feat. rustc sources)
• [video] Beginner's guide to Rust's Result, "?" and Try/FromResidual
• [video] Crust of Rust: std::collections
• [ES] [video] Introducción a Rust en Español, Parte 2: Todo sobre variables, let, mut, scopes, tipos y más.

Miscellaneous

• How Rust-based search engine Meilisearch uses dynamic virtual address management to scale indexes
• The Way of the Crab Podcast, Epside 1: Hello, World!
• Hangman over QUIC (using Rust and Quinn)

Crate of the Week

This week's crate is dlhn, a serde-compatible serialization format geared for performance.

Thanks to Shogo Otake 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.

• velo - Implement simple bevy-markdown renderer
• ockam - #[ockam::node] macro doesn't handle returned errors
• ockam - Make clap command asynchronously wait for the changes to take place
• Hyperswitch - move connector config to a separate file
• Hyperswitch - Implement ReverseLookupInterface for MockDb
• Hyperswitch - Implement EventInterface for MockDb

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

Calls for Proposals

Open calls for submissions to conferences and meetups.

• EuroRust Call for Speakers (By 2023-06-11)

Updates from the Rust Project

386 pull requests were merged in the last week

• implement c"foo" literals (RFC #3348)
• output LLVM optimization remark kind in -Cremark output
• STD support for PSVita
• add force option for --extern flag
• rustc_middle: Fix opt_item_ident for non-local def ids
• add FreeBSD cpuset support to std::thread::available_concurrency
• add deployment-target --print flag for Apple targets
• add hint for =< as <=
• avoid alignment mismatch between ABI and layout for unions
• check arguments length in trivial diagnostic lint
• check array type of repeat exprs is wf
• constProp into PlaceElem::Index
• constify slice flatten method
• correctly recurse when expanding anon consts
• debuginfo: split method declaration and definition
• disable nrvo mir opt
• do not recurse into const generic args when resolving self lifetime elision
• don't bail out early when checking invalid repr attr
• don't compute trait super bounds unless they're positive
• don't validate constants in const propagation
• emit while_true lint spanning the entire loop condition
• enable rust_2018_idioms lint group for doctests
• encode def span for foreign return-position impl Trait in trait
• ensure test library issues json string line-by-line
• expand the LLVM coverage of --print target-cpus
• explicitly reject negative and reservation drop impls
• fix elaboration with associated type bounds
• fix lifetime suggestion for type aliases with objects in them
• fix miscompilation when calling default methods on Future
• fix some suggestions where a Box<T> is expected
• fix spans in LLVM-generated inline asm errors
• forbid escaping bound vars in combine
• further normalize msvc-non-utf8-ouput
• implement tuple<->array convertions via From
• implement negative bounds for internal testing purposes
• interpret: fail more gracefully on uninit unsized locals
• introduce AliasKind::Inherent for inherent associated types
• leave promoteds untainted by errors when borrowck fails
• make PlaceMention a non-mutating use
• make (try_)subst_and_normalize_erasing_regions take EarlyBinder
• make generics_of has_self on RPITITs delegate to the opaque
• make some simple queries no longer cache on disk
• optimize builder sizes
• prevent aborting guard from aborting the process in a forced unwind
• reduce MIR dump file count for MIR-opt tests
• refactor core::char::EscapeDefault and co. structures
• reject borrows of projections in ConstProp
• replace tcx.mk_trait_ref with TraitRef::new
• suggest struct when we get colon in fileds in enum
• support return-type bounds on associated methods from supertraits
• uplift clippy::clone_double_ref as suspicious_double_ref_op
• use fulfillment to check Drop impl compatibility
• miri: avoid interpreting code that has lint errors
• miri: clearer variable names in data_race
• miri: simplify event selection in TB diagnostics
• box AssertKind
• stabilize debugger_visualizer
• stabilize raw-dylib, link_ordinal, import_name_type and -Cdlltool
• partial stabilisation of c_unwind
• inline SocketAddr methods
• add 64-bit time_t support on 32-bit glibc Linux to set_times
• make sure the implementation of TcpStream::as_raw_fd is fully inlined
• add ascii::Char
• assume the runtime range of align_offset
• btree_map: Cursor{,Mut}::peek_prev must agree
• add is_positive method for signed non-zero integers
• constify [u8]::is_ascii (unstably) 
• fix checked_{add,sub}_duration incorrectly returning None when other has more than i64::MAX seconds
• correctly convert an NT path to a Win32 path in read_link
• libtest: include test output in junit xml reports
• hashbrown: mark RawTable::data_start NonNull
• hashbrown: special case clear() on empty tables
• cargo: metadata: add workspace_default_members
• cargo: do not try an exponential number of package names
• cargo: remove repeated definite articles
• cargo: support for shallow clones and fetches with gitoxide
• rustdoc-search: add slices and arrays to index
• rustdoc: restructure type search engine to pick-and-use IDs
• clippy: imprecise_flops: Globally ignore #[no_std] crates
• clippy: wildcard_imports ignore test.rs files
• clippy: add lint to detect construction of unit struct using default
• clippy: ignore borrow_deref_ref warnings in code from procedural macros
• clippy: ignore expressions from macros in default_constructed_unit_structs
• clippy: initial clippy::ref_patterns implementation
• rust-analyzer: add config for disabling hover memory layout data
• rust-analyzer: closure capture inlay hints
• rust-analyzer: creating rust dependencies tree explorer
• rust-analyzer: define problem matcher for panics in VS Code
• rust-analyzer: emit function bodies in expanding builtin derives
• rust-analyzer: fix pattern type mismatches for bindings, enable pattern type mismatch diagnostics again
• rust-analyzer: highlight closure captures when cursor is on pipe or move keyword
• rust-analyzer: fix body lowering not using block def maps
• rust-analyzer: fix some mir related bugs
• rust-analyzer: generate delegate methods filters out functions that already exist on the struct's impls
• rust-analyzer: ide: do not highlight escapes in raw strings
• rust-analyzer: ide: exclude sized in go-to actions in hover
• rust-analyzer: ignore impls with #[rustc_reservation_impl]
• rust-analyzer: lazy evaluate consts in path_to_const
• rust-analyzer: only pass unstable flags to cargo metadata from extra args config
• rust-analyzer: parse bare dyn types with leading lifetime
• rust-analyzer: show type alias layout
• rust-analyzer: sort rust dependencies in vscode tree view

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 a [lints] table to Cargo.toml

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

• New rustc and Cargo options to allow path sanitisation by default

Tracking Issues & PRs

• [disposition: merge] Remove misleading target feature aliases
• [disposition: merge] expand: Change how #![cfg(FALSE)] behaves on crate root
• [disposition: merge] do not allow inference in predicate_must_hold (alternative approach)
• [disposition: merge] Tracking Issue for slice::split_at in const context
• [disposition: merge] Implement AsHandle/AsSocket for Arc/Rc/Box on Windows

New and Updated RFCs

• [new] RFC: Unix socket ancillary data v2

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 2023-05-10 - 2023-06-07 🦀

Virtual

• 2023-05-10 | Virtual (Boulder, CO, US) | Boulder Elixir and Rust
  • Monthly Meetup
• 2023-05-11 | Virtual (Nürnberg, DE) | Rust Nuremberg
  • Rust Nürnberg online
• 2023-05-11 | Virtual (South Pasadena, CA, US) | Pasadena Thursday Go / Rust
  • Weekly study group
• 2023-05-13 | Virtual | Rust GameDev
  • Rust GameDev Monthly Meetup
• 2023-05-13 | Virtual + In person (Singapore, SG) | Web3Dev.Community
  • [Hybrid] You'll Never Rust Alone - Rust Study Group
• 2023-05-16 | Virtual (Washington, DC, US) | Rust DC
  • Mid-month Rustful
• 2023-05-17 | Virtual (Cardiff, UK) | Rust and C++ Cardiff
  • Rust Atomics and Locks Book Club Chapter 2
• 2023-05-17 | Virtual (Vancouver, BC, CA) | Vancouver Rust
  • Spin and Kata Containers
• 2023-05-18 | Virtual (Stuttgart, DE) | Rust Community Stuttgart
  • Rust-Meetup
• 2023-05-20 | Virtual + In person (Singapore, SG) | Web3Dev.Community
  • [Hybrid] You'll Never Rust Alone - Rust Study Group
• 2023-05-23 | Virtual (Berlin, DE) | OpenTechSchool Berlin
  • Rust Hack and Learn
• 2023-05-25 | Virtual (Charlottesville, VA, US) | Charlottesville Rust Meetup
  • Practical Monads
• 2023-05-25 | Virtual (Ciudad de México, MX) | Rust MX
  • Proyecto "Taller de Rust"
• 2023-05-25 | Virtual (Karlsruhe, DE) | The Karlsruhe Functional Programmers Meetup Group
  • Stammtisch (gemeinsam mit der C++ UG KA) - various topics, from C++ to Rust
• 2023-05-25 | Virtual (San Francisco, CA, US) | Data + AI Online Meetup
  • D3L2: Discussing Rust, Ballista, Ray SQL, DataFusion with Andy Grove
• 2023-05-30 | Virtual (Dallas, TX, US) | Dallas Rust
  • Last Tuesday
• 2023-05-31 | Virtual (Chicago, IL, US) | Chicago Healthcare Cloud Technology Community
  • Rust for Mission-Critical AI: A Journey into Healthcare's Safest Language
• 2023-06-06 | Virtual (Austin, TX, US) | WebAssembly and WasmEdge
  • Monthly WasmEdge Community Meeting - Run Rust Warp in WasmEdge -- Alan, Poon Yong Quan
• 2023-06-06 | Virtual (Buffalo, NY, US) | Buffalo Rust Meetup
  • Buffalo Rust User Group, First Tuesdays
• 2023-06-07 | Virtual (Indianapolis, IN, US) | Indy Rust
  • Indy.rs - with Social Distancing

Asia

• 2023-05-13 | Singapore, SG | Web3Dev.Community
  • [Hybrid] You'll Never Rust Alone - Rust Study Group
• 2023-05-18 | Seoul, KR | Seoul Substrate Blockchain Meetup
  • **Seoul Substrate Meetup - 최신 cyprography - Rust
• 2023-05-20 | Singapore, SG | Web3Dev.Community
  • [Hybrid] You'll Never Rust Alone - Rust Study Group
• 2023-05-25 | Amsterdam, NL | Frontend Developer Meetup Amsterdam
  • Svelte Frontend Meetup (signup required) - Building a Svelte-Rust app using Tauri

Europe

• 2023-05-10 | Amsterdam, NL | RustNL
  • RustNL 2023
• 2023-05-19 | Stuttgart, DE | Rust Community Stuttgart
  • OnSite Meeting
• 2023-05-23 | Paris, FR | Kaïbee
  • Atelier Axum & Rust
• 2023-05-24 | Lyon, FR | Rust Lyon
  • Rust Lyon Meetup #4
• 2023-05-25 | Barcelona, ES | C++ Programmer Meetup.
  • Rust for C++ Developers.
• 2023-05-25 | Copenhagen, DK | Copenhagen Rust Community
  • Rust metup #36 at Adapt Agency!
• 2023-05-25 | Paris, FR | Rust Paris
  • Rust Paris meetup #59
• 2023-05-30 | Barcelona, ES | BcnRust
  • 10th BcnRust Meetup

North America

• 2023-05-11 | Lehi, UT, US | Utah Rust
  • Interesting Title and Food!
• 2023-05-16 | San Francisco, CA, US | San Francisco Rust Study Group
  • Rust Hacking in Person
• 2023-05-17 | New York, NY, US | Rust NYC
  • Too many unit tests: A tale of macros and BigDecimals

Oceania

• 2023-05-30 | Canberra, ACT, AU | Canberra Rust User Group
  • May 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

Thanks to all for the very helpful responses. "The Book" says The community is very welcoming and happy to answer students’ questions "; I expected that to be just marketing, but I was wrong."

– Daryl Lee on rust-users

Thanks to evann 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.

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Discuss on r/rust