Hello and welcome to the first issue of This Week In Rust, a weekly overview of Rust and its community. I'll be covering what's cooking in incoming, meeting summaries, meetups, and anything else pertinent. Any ideas, email them to me, corey+rust@octayn.net.

The Rust interns arrived this week and have got cracking right away. Big hello to Aaron Todd, Ben Blum, and Michael Sullivan! We can look forward to work all over the place, especially in the RT and debug-info.

What's cooking in incoming?

There were 30 pull requests merged this week. A scattering of doc fixes and a bunch of code cleanups and optimization work as usual. Total issue churn (excludes pull requests) this week was +6.

Notable additions, bugfixes, and cleanups

  • Ben Striegel added the as_c_str string function as a method as part of the overall methodization covered by 6045.
  • James Miller landed a much better optimization pipeline in 6881, fixing a bunch of nascent optimization problems, especially with inlining, and also fixing an earlier (huge) regression (that he introduced, admittedly).
  • James also fixed 6977, which allowed nonsensical expressions like [0, ..-1]. Whoops!
  • I introduced terminfo handling to extra::term in 6826, bringing rustc's beautiful colors to a wider audience. Unfortunately, it isn't complete yet and, most notably, does not handle xterm-256color correctly yet.
  • Daniel Micay landed jemalloc as the default allocator in the runtime, leading to nice allocation performance boosts on all platforms, as well as much improved multithreaded performance. It also has the benefit of cross-platform tuning and instrumentation.

Breaking changes

It would be silly not to mention these changes, even though they weren't strictly this week:

  • libcore was renamed to libstd and libstd was renamed to libextra, to better reflect their purpose. Confusingly, the code in rustc still uses the old names. Something to watch out for!
  • All of the module reexports were removed from the prelude, so if you use, for example, io::foo, vec::foo, etc, you will find yourself having to add a lot of extra imports. use std::* to regain the old behavior, more or less.
  • Patrick fixed the unsafe checker to safe code can no longer call unsafe methods.

This week:

  • pub impl was removed by Patrick Walton as part of 6944. What this did was have all fns in a pub impl be pub by default. Now, you must explicitly specify pub on all fns in the impl if you want them public.
  • Also in 6944, Patrick removed the ability to have multiple patterns appear in "let" declarations. For example: let a = 4, b = 2; becomes let (a, b) = (4, 2);
  • Daniel renamed the Ptr trait to RawPtr in 6913
  • Daniel and Huon Wilson have been working on iterators a lot. In 6999, they start removing the vec::each_* functions, as the new iterator code in std::iterator is now mature enough for use.


There were two main meetings this week. Mostly discussion about DST, closures, and the GC. Lots of issues and details remain to be worked out, I suspoect it will still be a bit before anything final-looking comes up in a PR. See the meeting notes for more details.


  • Erick Tryzelaar has a meetup planned in Mountain View on Wednesday, June 12, at 7pm. See the ML thread for more details.
  • Tim Chevalier will be giving a talk titled "Rust: A Friendly Introduction" on Monday, June 17, 6-9pm in Portland. See Calagator for more details.

Prominent blog posts and ML threads

Other announcements

  • 10gen has some interns working on a MongoDB driver for Rust, which will be very nice to have. Good luck to them!
  • Brendan Zabarauskas has fixed lmath. It now works on incoming. Yay!

Brendan sent in a correction:

{% blockquote %} Unfortunately whilst it builds on incoming, due to a bug you can't use it in external crates. moonchrome and I am are working on fixing this but it will require us to remove the trait heirachy and use macros to generate each type (Vec3f, Vec3f32, ... etc.) individually instead. Integer and Boolean vector types (present in GLSL) will also be removed.