Version 1.34 of the Rust systems programming language is now available.

  • Cargo, the project and package management system for Rus, now works with registries other than the default (, including . Note that any Crates hosted on can only depend on Crates also in
  • The ? operator, used for unpacking errors and valid values from Result types, can now be used in . This makes it possible to write more fully fleshed out test examples alongside the code being documented.
  • Custom attributes can now accept arbitrary token streams. This allows custom attributes in procedural macros to be more succinct and use more idiomatic Rust code.
  • The TryFrom and TryInto traits can now allow type conversions that might allow failure.
  • Many library and API stabilizations have been added, such as support for a wider range of atomic integer types (which can be shared safely between threads).