num_enum

num_enum handles safe enum-to-integer and integer-to-enum conversions via IntoPrimitive, TryFromPrimitive, and FromPrimitive derives. It supports #[num_enum(alternatives = [...])] for multiple integer values mapping to one variant and #[num_enum(catch_all)] for wildcard variants.

This is critical for FFI and protocol parsing where raw as casting silently truncates or produces UB. strum's FromRepr covers simpler cases; num_enum is the better choice when you need alternatives, catch-all, or TryFrom semantics. See rust-enum-crates.