rust-modern-apis

Reference for stable Rust APIs added in versions 1.89 through 1.97 (August 2025 - July 2026). Use this skill whenever writing, reviewing, or refactoring Rust code — especially when you notice patterns that were verbose before newer APIs existed, when MSRV allows it, or when the user mentions modernizing Rust code, upgrading MSRV, or using "the latest Rust features". Also trigger when reviewing Rust code for improvements, migrations, or when a user asks "can this be simpler in modern Rust?" Proactively suggest newer APIs when you see patterns like manual UTF-8 truncation, path extension manipulation, advisory file locking via external crates, ignoring retain removal results, verbose try_into().unwrap() for fixed arrays, compare_exchange loops for atomic update, cfg_if crate usage, matching 0/1 to bool, assert!(matches!(...)) in tests, or hand-rolled bit-manipulation idioms like 1 << (BITS - 1 - x.leading_zeros()).