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

Rust's type system is Turing-complete: An exploration of type-level programming in Rust. A response to Rust's type system is not Turing complete challenge.
Targeting the web with Rust. A demo web app that implements CPU bound portions in Rust (compiled to wasm/asm.js) while using existing web technologies to handle user facing pieces.
Gentle intro to type-level recursion in Rust: From zero to HList sculpting.
Math with distances in Rust: safety and correctness across units.
Exploring dynamic dispatch in Rust.
Running Rust on the ARM Cortex M3.
Little tour of multiple iterators implementation in Rust.
How to use Hyper HTTP library asynchronously.
Building a parallel ECS in Rust. The development story of specs commemorating the 0.8 version release.
Map of a lifetime. flat_map vs. nested loops.
Reference iterators in Rust.
ripgrep 0.5.0 released with UTF-16 support. ripgrep is a line oriented search tool that combines the usability of The Silver Searcher with the raw speed of GNU grep.
Rust now beats C++ in many benchmarks in The Computer Language Benchmarks Game and is on par in others.
This week in Rust docs 47.
Parsing into an AST. Part of the series - Writing an interpreter in Rust.

Crate of the Week

This week's crate of the week is µtest, a testing framework for embedded software. Thanks to nasa42 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.

Crossbeam project is looking for new maintainers.
The Underhanded Rust Contest.
[medium] notify-rust: Implement icons and images. notify-rust let's you send desktop notifications on Linux and BSD.
tempdir: TempDir affected by remove_dir_all unreliability on windows.
[easy] servo: Looking for something to work on.

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

Updates from Rust Core

142 pull requests were merged in the last week.

New Contributors

CrazyMerlyn
Fabjan Sukalia
Gibson Fahnestock
Joel Gallant
Jonas Bushart
Joshua Horwitz
madseagames
Paul Daniel Faria
Petr Hosek
Tobias Schottdorf

Approved RFCs

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

RFC 1845: From<&[T]> for Rc<[T]> + From<&str> for Rc<str>.

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. This week's FCPs are:

[disposition: merge] Add unstable sort to libcore.
[disposition: merge] Write to standard error with eprint! and eprintln!.
[disposition: merge] Include the ManuallyDrop wrapper in core::mem.
[disposition: merge] extend ? to operate over other types.
[disposition: close] Add variable-length arrays to the language.
[disposition: merge] Extend entry API to work on borrowed keys.
[disposition: merge] Deprecate anonymous parameters.

New RFCs

Allow the name (qualifier) of an enum variant to be elided in expressions and patterns whenever it can be inferred.

Style RFCs

Style RFCs are part of the process for deciding on style guidelines for the Rust community and defaults for Rustfmt. The process is similar to the RFC process, but we try to reach rough consensus on issues (including a final comment period) before progressing to PRs. Just like the RFC process, all users are welcome to comment and submit RFCs. If you want to help decide what Rust code should look like, come get involved!

PRs in final comment period: