compact-option-proc-macro
Procedural-macro companion to compact-option: #[compact_option(repr(R = …, sentinel = …))].
It targets the same core use case: a niche-packing optional that uses exactly as much memory as raw R, intended for R values with spare bit patterns (primarily #[repr(u8)] enums with fewer than 256 variants).
See the repository for usage and safety notes.
Licensed under the MIT license (see the LICENSE file in the repository root).