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? Tweet us at @ThisWeekInRust 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

• Lang team March update
• Rust Compiler March 2022 Steering Cycle

Newsletters

• This Month in Rust GameDev #31 - February 2022

Project/Tooling Updates

• Rust-Analyzer Changelog #120
• Tantivy 0.17 is out | Quickwit
• Knurling-rs changelog #34
• Fornjot (Code-CAD in Rust) - Weekly Dev Log - 2022-W10
• Slint Version 0.2.1 released -- weekly update
• Arti 0.1.0 is released: Your somewhat-stable API is here!
• Dioxus v0.2 Release: TUI, Router, Fermi, and Tooling
• This week in Databend #33: A Modern Cloud Data Warehouse for Everyone

Observations/Thoughts

• Introducing Rustler Precompiled - Dashbit Blog
• Announcing Savage, a computer algebra system written in Rust
• Oxide at Home: Propolis says Hello
• Things I hate about Rust, redux
• Async IO with completion-model IO systems
• Transcript: What's New in Rust 1.58 and 1.59
• [video] Rust Gamedev Meetup #14: March 2022
• [video] Rust fuzzing using cargo-libafl (LibAFL-based fuzzer) - Rust Security #4
• [audio] Interview with Fish Fight | Rust Game Dev
• [audio] PancakeDB with Martin Loncaric :: Rustacean Station

Rust Walkthroughs

• An In-Depth Introduction To Idempotency | A learning journal
• A Rust Gem: The Rust Map API
• RPATH, or why lld doesn’t work on NixOS
• Rust WebAssembly OCR experiments

Miscellaneous

• AUTOSAR announces WG for Rust in automotive
• [audio] Nick Cameron on Juggling Open Source Work and Parenthood
• [audio] Devtools podcast: building a new terminal in Rust

Crate of the Week

This week's crate is noline, a small no-std compatible readline-like line editor.

A lack of suggestions notwithstanding, llogiq is pretty pleased with his choice.

Please submit your suggestions and votes for next week!

Call for Participation

Always wanted to contribute to open-source projects but didn't 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.

Boa

• Good first issues
• Help wanted issues

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

Updates from the Rust Project

302 pull requests were merged in the last week

• diagnostics: do not spuriously claim something is "not an iterator"
• diagnostics: single colon within <> probably, not type ascription
• improve suggestion when casting usize to (possibly) wide pointer
• warn users about || in let chain expressions
• suggest if let/let_else for refutable pat in let
• suggest using double colon when a struct field type include single colon
• miri: implement simd_{shuffle, gather, scatter}
• CTFE/Miri: detect out-of-bounds pointers in offset_from
• change several HashMaps to IndexMap to improve incremental hashing performance
• improve AdtDef interning
• optimize ascii::escape_default
• make some Clone impls const
• remove argument from closure in thread::Scope::spawn
• use MaybeUninit in VecDeque to remove the undefined behavior of slice
• constify Index{,Mut} for [T], str, and [T; N]
• fix soundness issue in scoped threads
• implement BITS constant for non-zero integers
• implement MIN/MAX constants for non-zero integers
• add Result::{ok, err, and, or, unwrap_or} as const
• add Atomic*::get_mut_slice
• add core::hint::must_use
• unix: reduce the size of DirEntry
• portable-simd: add .min and .max for integers
• compiler-builtins: add support for Apple watchOS
• futures: add Mutex::lock_owned and Mutex::try_lock_owned
• rustfmt: improve mod resolution error for mods with multiple candidate files
• clippy: improve styles of filtering options for Clippy's lint list
• clippy: new lint that detects useless match expression
• clippy: new lint: only_used_in_recursion
• clippy: allow single_component_path_imports for all macros
• clippy: make search_is_somes suggestion MachineApplicable

Rust Compiler Performance Triage

Largely a quiet week. The perf improvement highlight is the use of real world crates such as syn, cargo, and serde in the collecting of profile guided optimization (PGO) profiles. Previously only libcore was used. This led to some decent improvement in compilation of real world crates (upwards of 5.5%).

On the regression side, the regressions were all largely small but contained inside of rollups making them hard to diagnose and correct. The perf team continues to work on process improvements that make changes to the compiler land through CI quickly while minimizing perf regressions that can sneak through.

Triage done by @rylev. Revision range: 10dccdc..3ba1eb

2 Regressions, 3 Improvements, 3 Mixed; 3 of them in rollups 42 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:

• Cargo alternative registry auth

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] Tracking Issue for JoinHandle::is_finished
• [disposition: merge] Tracking issue for const extern fn and const unsafe extern fn
• [disposition: merge] Always evaluate all cfg predicate in all() and any()

New and Updated RFCs

• [new] RFC: Packages as (optional) namespaces

Upcoming Events

Rusty Events between 2022-03-16 - 2022-04-13 🦀

Virtual

• 2022-03-16 | Egg Harbor City, NJ, US | Neighborhood Math Club
  • The Early Rustacean Gets The Worm!
• 2022-03-16 | Seattle, WA, US | Seattle Rust Meetup
  • Monthly meetup
• 2022-03-16 | Vancouver, BC, CA | Vancouver Rust
  • Building a Randomizer
• 2022-03-16 | Wien, AT | Mob-Programming on Open Source Software
  • The Rustic Mob
• 2022-03-17 | Stuttgart, DE | Rust Community Stuttgart
  • Rust-Meetup
• 2022-03-23 | Egg Harbor City, NJ, US | Neighborhood Math Club
  • The Early Rustacean Gets The Worm!
• 2022-03-24 | Charlottesville, VA, US | Charlottesville Rust Meetup
  • Embedded Rust reaching out--Learn how Rust can interact with the outside world
• 2022-03-24 | Linz, AU | Rust Linz
  • Rust Meetup Linz - 20th Edition
• 2022-03-29 | Berlin, DE | Berline
  • Rust Hack and Learn Tuesday
• 2022-03-29 | Dallas, TX, US | Dallas Rust
  • Last Tuesday
• 2022-03-30 | México City, MX | Rust MX
  • Platica Marzo 2022 - Reescribir o no reescribir aplicaciones en Rust
• 2022-04-05 | Beijing, CN | WebAssembly and Rust Meetup (Rustlang)
  • Monthly WasmEdge Community Meeting, a CNCF sandbox WebAssembly runtime
• 2022-04-05 | Buffalo, NY, US | Buffalo Rust Meetup
  • Buffalo Rust User Group, First Tuesdays
• 2022-04-05 | Denver, CO, US | Rust Denver
  • Using Futures to wrap an unsafe USB API to play audio directly - with live stream
• 2022-04-06 | Egg Harbor City, NJ, US | Neighborhood Math Club
  • The Early Rustacean Gets The Worm!
• 2022-04-06 | Indianapolis, IN, US | Indy Rust
  • Indy.rs - with Social Distancing
• 2022-04-07 | Nürnberg, DE | Rust Nuremberg
  • Rust Nürnberg online #12
• 2022-04-12 | Dallas, TX, US | Dallas Rust
  • Second Tuesday
• 2022-04-12 | Seattle, WA, US | Seattle Rust Meetup
  • Monthly Meetup
• 2022-04-13 | Boulder, CO | Boulder Elixir and Rust
  • Monthly Meetup
• 2022-04-13 | Egg Harbor City, NJ, US | Neighborhood Math Club
  • The Early Rustacean Gets The Worm!
• 2022-04-13 | Munich, DE | Rust Munich
  • Rust Munich 2022 / 1 - hybrid

Europe

• 2022-03-17 | Edinburgh, UK | Rust Edinburgh
  • Rust Night March, Edinburgh
• 2022-04-12 | Berlin, DE | Rust Berlin
  • Rust and Tell - an onsite event | Alt Link
• 2022-04-13 | Munich, DE | Rust Munich
  • Rust Munich 2022 / 1 - hybrid

North America

• 2022-04-05 | Denver, CO, US | Rust Denver
  • Using Futures to wrap an unsafe USB API to play audio directly - with live stream
• 2022-04-13 | Atlanta, GA, US | Rust ATL
  • Grab a beer with fellow Rustaceans

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.

Rust Jobs

Juspay

• Freelance Rust Developer (Remote)

Komodo

• Software Developer interested in learning Rust (Remote)

Stockly

• Back-end developer - TechOps (Rust, gRPC, PostgreSQL) (Paris, FR)
• Back-end developer - Engine (Rust, gRPC, PostgreSQL) (Paris, FR)

Kollider

• Senior Frontend Engineer - Rust (Remote)
• Junior Backend Engineer - Rust (Remote)

Tempus Ex

• Several full-time Rust positions available (San Francisco, CA, US, Atlanta, GA, US, Austin, TX, US, and Remote)

Tweet us at @ThisWeekInRust to get your job offers listed here!

Quote of the Week

protip: the rust extern keyword has a --help flag

``text error[E0703]: invalid ABI: found--help` --> ext.rs:1:8 | 1 | extern "--help" {} fn main() {} | ^^^^^^^^ invalid ABI | = help: valid ABIs: Rust, C, C-unwind, cdecl, stdcall, stdcall-unwind, fastcall, vectorcall, thiscall, thiscall-unwind, aapcs, win64, sysv64, ptx-kernel, msp430-interrupt, x86-interrupt, amdgpu-kernel, efiapi, avr-interrupt, avr-non-blocking-interrupt, C-cmse-nonsecure-call, wasm, system, system-unwind, rust-intrinsic, rust-call, platform-intrinsic, unadjusted

error: aborting due to previous error

For more information about this error, try rustc --explain E0703. ```

– Aria the Cat (with some help from rustc) on twitter

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.

Email list hosting is sponsored by The Rust Foundation

Discuss on r/rust