unitscale_macros

Overview

unitscale_macros provides procedural macros to simplify creating unit types and scale constants. This crate depends on unitscale_core and is intended to reduce boilerplate.

It exports two attribute macros:

• #[unit_scale(to = float)]: Declares a scale struct implementing UnitScaleF32.
• #[unit_data]: Generates a generic struct for the unit and implements TryFrom<f32>, Scaled<U>, and new().
• Optional with to specify "f32" or "f64" precision (Defaults to f32).
  • Note You cannot mix and match f32 and f64 versions of UnitTypeF* and UnitScaleF*.

Example

use unitscale_core::*;
use unitscale_macros::*;

// Default is `f32`. If you want f64 then you can add `with = "f64"`.

// #[unit_scale(to = 0.1, with = "f64")]
#[unit_scale(to = 0.1)]
struct Scale0_1;

// #[unit_type(with = "f64")]
#[unit_type]
struct Volts;

let v = Volts::<Scale0_1, u16>::try_from(3.2).unwrap();
// v.to_f32()) gives back 3.2 within the precision limit of the type (e.g. u16)
assert_eq!(v.scaled_value(), 32);