compact-option

CompactOption<R, T> is a niche-packing optional: it stores either NONE or a Some(T) payload in exactly as much memory as raw R, where T: Copy via the unsafe CompactRepr contract. It is intended for R types with spare bit patterns; the primary use case is #[repr(u8)] enums with fewer than 256 variants.

See the repository for examples and the optional macros feature.

Licensed under the MIT license (see the LICENSE file in the repository root).