Efficient Enum

This crate aims to bring some space-efficient tagged unions similar to enums. Instead of adding an extra bit, a bit of the existing structure is used. Users can customize which bit should be used at compile time.

For the moment, only EfficientOption and EfficientOptionTuple are provided, due to Rust's lack of a const fn version of size_of, which is needed to make size guarantees.

License

Licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.