# Unit Types > **DO NOT USE IN PRODUCTION!** This is a learning project and is not intended for production use. Some of the conversion numbers were automatically filled out by GitHub Copilot and have not yet been validated. > > I have not yet determined how far I will take this project. Forks or > contributions are welcome. The `unit_types` crate is a dimensionally aware type system for Rust. **Example:** ```rust use unit_types::prelude::*; // brings in "unit" use unit_types::Length; let x = Length::Kilometers(1.0); let y = Length::Meters(200.0); assert_eq!(x - y, Length::Meters(800.0)); assert_eq!(x + y, Length::Meters(1200.0)); let z = 2.0 * (x + y); // should be in Kilometers assert_eq!(z.value(), 2.4); assert_eq!(z.to(unit::Meters).value(), 2400.0); ```