the overarching team for the language and compiler
compiler internals, optimizations
designing new language features
Improving code generated by rustc.
Unsafe Code Guidelines (UCG)
Working out the "Unsafe Code Guidelines", which define what kind of behavior unsafe code can and cannot do.
Chat Channel: wg-unsafe-code-guidelines stream on Zulip
Improving rustc compilation performance (build times).
Working out a the official, formal grammar for Rust and validating it against existing implementations.
Non-Lexical Lifetimes (NLL)
Implementing the new MIR-based borrow check and non-lexical lifetimes.
Chat Channel: wg-nll stream on Zulip
Revamping the rustc trait implementation to follow the Chalk approach.