Rust 1.84 introduces strict provenance APIs, new trait solver, updated Cargo, and more

Rust has released version 1.84 of its programming language, introducing key updates to enhance developer experience and code reliability. A significant change in this release is the update to Cargo, which now considers Rust versions for dependency selection. This update stabilizes the minimum supported Rust version (MSRV) aware resolver, allowing library authors more flexibility and reducing the manual effort needed to support older toolchains.

The Rust compiler is transitioning to a new implementation for the trait solver, a core component of Rust's type system. This update addresses a few theoretical correctness issues present in the previous implementation, potentially leading to conflicting implementations of trait errors that were not previously reported.

Additionally, Rust 1.84 introduces strict provenance APIs, by integrating a set of APIs designed to replace integer-pointer-casts, reducing ambiguities and enhancing code safety. This allows developers to use aligned pointers to store extra information without casting between pointers and integers.

The release also includes stabilized APIs, along with various minor enhancements and bug fixes, continuing Rust's commitment to improving its language and toolchain.