Summary About this guide Getting started Reviewer checklist The feature lifecycle Landing new features Using tracking issues Stabilizing features Deprecating features Code considerations Design Public APIs When to add #[must_use] Breaking changes Breakage from changing behavior Breakage from new trait impls #[fundamental] types Safety and soundness Generics and unsafe Drop and #[may_dangle] std::mem and exclusive references Using unstable language features Const generics Specialization Performance When to #[inline] Documentation doc alias policy Tools and bots @bors @rust-timer @craterbot