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

Project/Tooling Updates

• rust-analyzer - changelog #144
• IntelliJ Rust Changelog #177
• Diesel 2.0.0
• Helix editor 22.08 released
• This Month in hyper: August 2022
• Fornjot - Weekly Release - 2022-W35
• Announcing Sycamore v0.8.0
• Announcing finl_unicode 1.0.0
• Slint UI crate weekly updates
• argmin 0.7.0 and argmin-math 0.2.0 released
• Update-informer v0.5.0
• This week in Databend #57: A Modern Cloud Data Warehouse for Everyone

Observations/Thoughts

• Solving The Witness with Z3 (Part 1)
• Static streams for faster async proxies
• Building an authentication system in Rust using session tokens
• OpenTelemetry Distributed Tracing in Rust
• Toward fearless cargo update

Rust Walkthroughs

• Learning Rust: Combinators
• Integrating Rust With Android Development — Final Part
• Rewriting my blog in Rust for fun and profit
• Building A Gamedev Maths Library In Rust From Scratch – Alex Dixon
• Pattern Matching and Backwards Compatibility
• Writing FreeBSD Kernel Modules in Rust
• [series] Ruxel - Building a Ray Tracer with Rust Part 1
• [series] STM32F4 Embedded Rust at the HAL: Timer Interrupts - Part 2
• [video] Using Rust to understand The Little Schemer
• [video] Building a Rust Multithreaded Web Server (chapter 20 of Rust Book)

Miscellaneous

• The Bombercrab Challenge 💥💣🦀
• [video] Unsafe Rust is not C
• [video] Building a space station in Rust (Simple Rust patterns)
• [video] Arvid Norberg: What C++ engineers can learn from Rust

Crate of the Week

This week's crate is bytehound a memory profiler for Rust.

Thanks to Aleksey Kladov 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 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.

• Ogma - Alter Expecting enum to be a bitflag
• Artichoke - Add wasi platform support to scolapasta-path
• Blaze-rs - Fixing the lost references issue
• Tool-sync - Support not only 'latest' releases
• Ockam - Improve output of ockam secure-channel list command for formatting, color, and json
• Ockam - Improve output of ockam tcp-connection create command for formatting, color, and json
• Ockam - Rename --node argument of ockam secure-channel list to --at
• Space-craft - Project contributions, migration from amytheyst

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

Updates from the Rust Project

412 pull requests were merged in the last week

• add the armv4t-none-eabi target to the supported_targets
• stabilize split debuginfo on linux
• add GDB/LLDB pretty-printers for NonZero types
• fix const: dynamic checks for accessing statics
• improve const mismatch FulfillmentError
• provide structured suggestion for hashmap[idx] = val
• suggest adding a missing semicolon before an item
• suggest alternatives when trying to mutate a HashMap/BTreeMap via indexing
• use smaller span for suggestions
• migrate rustc_attr crate diagnostics
• migrate rustc_interface diagnostics
• migrate rustc_lint errors to SessionDiagnostic
• migrate rustc_plugin_impl to SessionDiagnostic
• migrate rustc_ty_utils to SessionDiagnostic
• migrate ast lowering to session diagnostic
• migrate part of rustc_infer to session diagnostic
• migrate rustc_driver to SessionDiagnostic
• migrate rustc_mir_dataflow to diagnostic structs
• miri: adding support for external C functions that have integer (or empty) args and/or returns
• miri: skip field retagging on ZSTs, it can take forever
• miri: strengthen C++20 SC accesses
• avoid cloning a collection only to iterate over it
• reduce code size of assert_matches_failed
• shrink FnAbi
• shrink thir::Expr
• stabilize #![feature(label_break_value)]
• stabilize const_ptr_offset_from
• stabilize std::io::read_to_string
• add a File::create_new constructor
• add next_up and next_down for f32/f64
• is_whitespace() performance improvements
• add pointer masking convenience functions
• BTree: evaluate static type-related check at compile time
• fix Ipv6Addr::is_unicast_global to check for unicast global scope rebase
• windows: optimize Wtf8Buf::into_string for the case where it contains UTF-8
• properly forward ByRefSized::fold to the inner iterator
• make slice::{split_at, split_at_unchecked} const functions
• std::io: migrate ReadBuf to BorrowBuf/BorrowCursor
• rustdoc: rewrite error index generator to greatly reduce the size of the pages
• clippy: implemented suspicious_to_owned lint to check if to_owned is called on a Cow
• clippy: new lint: Raw slice pointer cast
• clippy: new multi_assignment lint
• clippy: don't lint needless_return if return has attrs
• clippy: don't lint literal None from expansion
• clippy: ignore match_like_matches_macro when there is comment
• clippy: remove parenthesis from unnecessary_cast suggestion
• clippy: rename manual_empty_string_creation and move to pedantic
• rust-analyzer: do not substitute Self when in same impl block
• rust-analyzer: move empty diagnostics workaround back into the server
• rust-analyzer: resolve doc links on impl blocks
• rustc-perf: add a metric containing the size of generated documentation

Rust Compiler Performance Triage

A somewhat difficult week to triage due to the large amount of noise coming from two benchmarks. Hopefully this noise settles down in the future. Other than that, improvements much outweighed regressions with an average of 142 changes to instruction count averaging 0.7% improvement. There were no huge wins this week, however.

Triage done by @rylev. Revision range: 4a24f08b..0631ea5d

Summary:

2 Regressions, 3 Improvements, 10 Mixed; 6 of them in rollups 40 artifact comparisons made in total

Full report

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.

Approved RFCs

Changes to Rust follow the Rust RFC (request for comments) process. These are the RFCs that were approved for implementation this week:

• Refined trait implementations

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] Stabilize raw-dylib for non-x86

New and Updated RFCs

• [new] Add core::mem::offset_of! RFC
• [new] De-RFC: Remove type ascription

Upcoming Events

Rusty Events between 2022-08-31 - 2022-09-28 🦀

Virtual

• 2022-09-01 | Virtual (PDT Timezone) | Conf42
  • Conf42: Rustlang 2022
• 2022-09-01 | Virtual | Google Open Source Live
  • Rust Day on Google Open Source Live
• 2022-09-02 | Virtual (Nürnberg, DE) | Rust Nuremberg
  • Rust Nuremberg Get Together
• 2022-09-03 | Virtual (Bangalore, IN) | Polkadot India
  • Substrate Saturday - Bootcamp Series 2: Fundamentals of Rust & Substrate
• 2022-09-03 | Virtual (Nürnberg, DE) | Rust Nuremberg
  • Deep Dive Session 1: Tokio my-redis Tutorial
• 2022-09-04 | Virtual (Seattle, WA, US) | Seattle Rust Meetup
  • Nine Rules for Elegant Rust Library APIs
• 2022-09-06 | Virtual (Beijing, CN) | WebAssembly and Rust Meetup (Rustlang)
  • Monthly WasmEdge Community Meeting, a CNCF sandbox WebAssembly runtime
• 2022-09-06 | Virtual (Buffalo, NY, US) | Buffalo Rust Meetup
  • Buffalo Rust User Group, First Tuesdays
• 2022-09-07 | Virtual (Indianapolis, IN, US) | Indy Rust
  • Indy.rs - with Social Distancing
• 2022-09-10 | Virtual | Rust GameDev
  • Rust GameDev Monthly Meetup
• 2022-09-10 | Virtual (Bangalore, IN) | Polkadot India
  • Substrate Saturday - Bootcamp Series 2: Fundamentals of Rust & Substrate
• 2022-09-12 | Virtual + Dublin, IE | Linux Plumbers Conference
  • Rust Microconference in LPC 2022 (Sep 12-14)
• 2022-09-13 | Virtual (Dallas, TX, US) | Dallas Rust
  • Second Tuesday
• 2022-09-13 | Virtual (Rostock, DE) | Altow Academy
  • Rust Meetup Rostock
• 2022-09-14 | Virtual (Malaysia)| Golang Malaysia
  • Rust Meetup September 2022
• 2022-09-14 | Virtual (Cardiff, UK) | Rust and C++ Cardiff
  • Introduction to Async in Rust
• 2022-09-14 | Virtual (Sydney, NSW, AU) | Rust Sydney
  • Rust-Sydney Lightning Talks
• 2022-09-15 | Virtual (Columbus, OH, US) | GDG Columbus
  • Past, Present, and Future of Internet Money! (Custom tokenomics, RUST and CosmWASM library...)
• 2022-09-20 | Virtual (Washington, DC, US) | Rust DC
  • Mid-month Rustful: Bencher—Catch Performance Regressions in CI—Everett Pompeii
• 2022-09-21 | Virtual (Vancouver, BC, CA) | Vancouver Rust
  • Rust Study/Hack/Hang-out (Call for Participation)
• 2022-09-22 | Virtual (Charlottesville, VA, US) | Charlottesville Rust Meetup
  • Rust based Bluetooth tools (BlueR) you can use today
• 2022-09-23 | Virtual (Tokyo, JP) | Rust Tokyo
  • Rust Tokyo 2022
• 2022-09-27 | Virtual (Dallas, TX, US) | Dallas Rust
  • Last Tuesday

Europe

• 2022-09-01 | Berlin, DE | Rust Berlin
  • Rust and Tell - BBQ Edition
• 2022-09-12 | Dublin, IE + Virtual | Linux Plumbers Conference
  • Rust Microconference in LPC 2022 (Sep 12-14)
• 2022-09-15 | Paris, FR | Rust Paris
  • Rust Paris meetup #52

North America

• 2022-08-31 | New York, NY, US | Rust NYC
  • August Meetup: Rewriting a high performance Vector Database in Rust.
• 2022-09-01 | Phoenix, AZ, US | Phoenix Android - GDG
  • Phoenix: Rust Day on Google Open Source Live Viewing party | Main event link

South America

• 2022-09-10 | São Paulo, BR | Rust São Paulo Meetup
  • iFood Tech Day: Rust

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

[W]e reached a tipping point. We decided to move our entire codebase to Rust... . Rust seemed to give us all the capabilities we needed, however, there was still one minor problem - no one on the team knew Rust. ...

We started with a small team of senior engineers and managers learning Rust and developing the skeleton of the DB and dev environment (for others to build on). Then, slowly, others joined in rewriting and contributing different components until we eventually got rid of the old codebase altogether (I still remember the day my original C modules, from the first days of Pinecone, were taken out). Unbeknownst to most Pinecone customers, the new Rust core was deployed in March this year. And in the process of taking over running workloads, we managed not to drop a single API call!

... We all expect[ed] performance and dev processes to improve. Those indeed happened. What we didn’t expect was the extent to which dev velocity increased and operational incidents decreased. Dev velocity ... improved dramatically with Rust. Built-in testing, CI/CD, benchmarking, and an overzealous compiler increased engineers’ confidence in pushing changes, and enabled them to work on the same code sections and contribute simultaneously without breaking the code base. Most impressively though, real time operational events dropped almost to zero overnight after the original release. Sure, there are still surprises here and there but, by and large, the core engine has been shockingly stable and predictable.

– Edo Liberty on the pinecone blog

Thanks to Erich Gubler 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.

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Discuss on r/rust