Hello and welcome to another issue of This Week in Rust! Rust is a systems language pursuing the trifecta: safety, concurrency, and speed. 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

No newsletters this week.

Official

• Launching the 2020 State of Rust Survey
• A call for contributors from the WG-prioritization team

Tooling

• Rust Analyzer Changelog #42

Observations/Thoughts

• Which Parsing Approach?
• Challenging LR Parsing
• What I Learnt from Benchmarking Http4k, Ktor (Kotlin) and Actix v2, v3 (Rust) Microservices
• No Namespaces in Rust is a Feature
• Building devserver: An Ultra-Tiny Rust Server
• Taming nalgebra's Rustdoc
• Rust in Science and ever-changing requirements
• From @Test to #[test]: an essay about testing between Java and Rust
• What I Learnt from Benchmarking Http4k, Ktor (Kotlin) and Actix v2, v3 (Rust) Microservices

Learn Standard Rust

• Collecting Data from an API
• SQLite File Parser Pt. 1: The Header
• An introduction to Data Oriented Design with Rust
• Rust for Java developers
• Oxidizing portals with zbus

Learn More Rust

• Implementing Records in x7
• Let's build a single binary gRPC server-client with Rust in 2020 - Part 4
• Make A Language - Part Three: Defining variables
• Rust HTTP Testing with httpmock

Project Updates

• Announcing the CCS811 indoor air quality sensor driver.
• OpenPGP in Rust: the Sequoia project
• AssemblyLift v0.2 preview: RPC-based IO modules
• Announcing Actix Web v3.0

Miscellaneous

• Your Language Sucks, It Doesn't Matter
• Rust is #18 in the TIOBE Index for September 2020
• A Few Github Action "Recipes" for Rust
• Writing an x86 bootloader in Rust that can launch vmlinux
• [video] GOTO 2020 - Next-Generation Programming: Rust & Elm - Richard Feldman

Call for Blog Posts

The Rust Core Team wants input from the community! If you haven't already, read the official blog and submit a blog post - it will show up here! Here are the wonderful submissions since the call for blog posts:

• Rust in 2021
• Rust 2021

Crate of the Week

This week's crate is gitoxide, an idiomatic, modern, lean, fast, safe & pure Rust implementation of git.

Thanks again to Vlad Frolov for the suggestion!

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.

No issues were proposed for CfP.

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

Updates from Rust Core

336 pull requests were merged in the last week

• add rust-dev component to support rustc development
• properly encode spans with a dummy location and non-root SyntaxContext
• add const_item_mutation lint
• more structured suggestions for boxed trait objects instead of impl Trait on non-coerceable tail expressions
• add help note when using type in place of const
• do not promote &mut of a non-ZST ever
• chalk: simplify lowering
• inliner: emit storage markers for introduced arg temporaries
• enable the SimplifyArmIdentity MIR optimization at mir-opt-level=1
• stabilize doc_alias
• stabilize core::future::{pending,ready}
• add saturating methods for Duration
• add slice::array_chunks_mut
• eliminate mut reference UB in Drop impl for Rc<T>
• BTreeMap mutable iterators should not take any reference to visited nodes during iteration
• BTreeMap: move up reference to map's root from NodeRef
• add drain_filter method to HashMap and HashSet
• arch: AVX512F
• add MaybeUninit::assume_init_drop
• remove internal and unstable MaybeUninit::UNINIT
• cargo: fix non-determinism with new feature resolver

Rust Compiler Performance Triage

• 2020-09-15: 0 regressions, 2 improvements.

A few small compile-time regressions this week. The first was #70793, which added some specializations to the standard library in order to increase runtime performance. The second was #73996, which adds an option to the diagnostics code to print only the names of types and traits when they are unique instead of the whole path. The third was #75200, which refactored part of BTreeMap to avoid aliasing mutable references.

Approved RFCs

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

• eRFC: Add JSON backend to Rustdoc

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

• [RFC]: Portable SIMD Libs Project Group
• Get type of an arbitrary expression
• Add generalized arity tuples

Tracking Issues & PRs

• [disposition: merge]Add [T; N]: TryFrom<Vec<T>> (insta-stable)
• [disposition: merge]Implementation of Write for some immutable ref structs
• [disposition: merge]Permit uninhabited enums to cast into ints
• [disposition: merge]Stabilize some Result methods as const
• [disposition: merge]Stabilize some Option methods as const
• [disposition: merge]Stabilize move_ref_pattern
• [disposition: merge]Explicitly document the size guarantees that Option makes.
• [disposition: merge]Stabilize intra-doc links
• [disposition: merge]target-feature 1.1: should closures inherit target-feature annotations?
• [disposition: merge]might_permit_raw_init: also check aggregate fields

New RFCs

• rustdoc edit links

Upcoming Events

Online

• September 16. Vancouver, BC, CA - Vancouver Rust - Rust Study/Hack/Hang-out night
• September 17. Linz, AT - Rust Linz - Rust Meetup Linz - Meaghan Lewis on Rust, Embedded Rust with Roland Ruckerbauer
• September 17. Berlin, DE - Berline.rs - Berlin Rust Hack and Learn
• September 29. Dallas, TX, US - Dallas Rust - Last Tuesday

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

• Backend Engineer - Rust at Kraken (Remote AMER or EMEA)
• Senior Backend Engineer - Rust at Kraken (Remote AMER or EMEA)
• Backend / Quant Developer at Kraken (Remote EMEA)
• Backend Engineer - Crypto/Payments at Kraken (Remote AMER, APAC, EMEA)
• Rust Software Engineer - Backend at ANIXE (Wrocław, PL)
• Senior Blockchain Engineer at PureStake (Boston, MA, US or Madrid, ES, or Remote)
• Senior Embedded Software Engineer at Georg Fischer (El Monte, CA, US)

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

Quote of the Week

When you have a lifetime <'a> on a struct, that lifetime denotes references to values stored outside of the struct. If you try to store a reference that points inside the struct rather than outside, you will run into a compiler error when the compiler notices you lied to it.

• Alice Ryhl on rust-users

Thanks to Tom Phinney for the suggestion!

Please submit quotes and vote for next week!

This Week in Rust is edited by: nellshamrell, llogiq, and cdmistman.

Discuss on r/rust