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

News & Blog Posts

• 🎈🎉 Announcing Rust 1.27. 🎉🎈
• Rust 2018: an early preview.
• Our vision for Rust and WebAssembly.
• Proposal for a staged RFC process.
• What I learned: Porting Dateutil parser from Python to Rust.
• Making Arc more atomic.
• Optimising path tracing: the last 10%.
• Rust with Rocket + Elm running on Heroku.
• Generic associated types in iterators.
• [podcast] Rusty Spike Podcast - episode 34. DivANS, IDE support, Aaron’s continued series, async/await, non-lexical lifetimes, and Rust Reach.
• [podcast] New Rustacean: e024 – Traits deep dive, part 2.

Crate of the Week

This week's crate is mutagen, a mutation testing framework for Rust. Thanks to llogiq 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.

• Get started with these beginner-friendly issues.

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

Updates from Rust Core

95 pull requests were merged in the last week

• async/await
• rename OOM to allocation error
• prohibit global_allocator in submodules
• run some stuff in parallel
• reduce number of allocations done by NLL
• NLL: walk the MIR only once for the "unused mut" lint
• NLL diagnostics: revise fn check_access_permissions
• improve memoization and refactor NLL type check
• add existential type definitions
• make more libsyntax methods public
• add ability to apply custom derive to union types
• The Great Generics Generalisation: HIR Edition
• fix processing mod with multi-level path on Windows
• disable probestack when GCOV profiling is being used
• support future deprecation for rustc_deprecated
• fix an ICE when matching over const slices
• yet another "old borrowck" bug around match default bindings
• fix erroneous error note when using field after move
• three diagnostics upgrades
• various changes to existing diagnostics
• don't suggest incorrect syntax
• use fstatat64 where available
• specialize StepBy<Range(Inclusive)>
• impl Hash for !
• stabilize std::path::Path::ancestors
• replace tempdir by tempfile
• rustdoc: greatly improve tables display
• rustbuild: use quiet tests by default
• ship LLVM tools with the toolchain

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] Allow panicking in constants.
• [disposition: merge] Allow loop in constant evaluation.
• [disposition: merge] Introduce #[do_not_recommend] to control errors for trait impls.
• [disposition: merge] Tuple struct construction with Self(v1, v2, ..).
• [disposition: merge] Update RFC 0430 to allow underscores between numbers in CamelCase names.
• [disposition: merge] Add Option::replace to the core library.
• [disposition: close] Reserve delegate as a keyword in edition 2018.
• [disposition: close] Reserve f(a = b) in Rust 2018.

Tracking Issues & PRs

• [disposition: merge] Tracking issue for "macro naming and modularisation" (RFC #1561).
• [disposition: merge] Tracking issue for ToOwned::clone_into (toowned_clone_into).
• [disposition: merge] extern type cannot support size_of_val and align_of_val.
• [disposition: merge] Tracking issue for the to_bytes and from_bytes methods of integers.
• [disposition: merge] Implement iter::{Sum<U>, Product<U>} for Option<T>.
• [disposition: merge] Implement PartialEq between &str and OsString.
• [disposition: merge] Remove quote_*! macros.
• [disposition: close] Can't overload indexing for arrays.

New RFCs

• Add new channels for long term support (LTS) releases.
• Stabilize the alloc crate.
• Conversions: FromLossy and TryFromLossy traits.

Upcoming Events

Online

• Jul 3. Rust Community Content Subteam Meeting at #rust-content on irc.mozilla.org.
• Jul 4. Rust Community Team Meeting at #rust-community on irc.mozilla.org.
• Jul 4. Rust Events Team Meeting.
• Jul 11. Rust Community Team Meeting at #rust-community on irc.mozilla.org.

Africa

• Jul 3. Johannesburg, ZA - Monthly Meetup of the Johannesburg Rustaceans.

Europe

• Jul 4. Dresden, DE - Mozilla Community Dresden - Rust Meetup.
• Jul 6. Darmstadt, DE - Rhein-Main Rust Meetup.
• Jul 9. Karlsruhe, DE - Rust Meetup
• Jul 11. Zurich, CH - Actix.rs - July Meetup.
• Jul 11. Berlin, DE - OpenTechSchool - Rust Hack and Learn.

North America

• Jul 1. Mountain View, US - Open Table / Icebreaker: what projects are you working on.
• Jul 4. Atlanta, US - Grab a beer with fellow Rustaceans.
• Jul 4. Indianapolis, US - Indy.rs.
• Jul 8. Mountain View, US - Open Table / Icebreaker: what projects are you working on.
• Jul 9. Seattle, US - Monthly Rust Meetup.
• Jul 11. Vancouver, CA - Rust Study/Hack/Hang-out night.
• Jul 12. Columbus, US - Columbus Rust Society - Monthly Meeting.
• Jul 12. Utah Valley, Utah, US - Utah Rust - Monthly Meeting.
• Aug 17. Portland, US - RustConf 2018. Registration is now open.

If you are running a Rust event please add it to the calendar to get it mentioned here. Email the Rust Community Team for access.

Rust Jobs

• Senior Software Developer at Nymi, Toronto, CA.
• Senior Rust Engineer at Ticketmaster, Arizona, US.

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

Quote of the Week

I’m hesitating in cc’ing [the crate author] because I’d rather this be an educational conversation, and not a unsafety witchhunt.

– vitalyd on rust-users

Please submit your quotes for next week!

This Week in Rust is edited by: nasa42 and llogiq.