Derive Macro Unit 

#[derive(Unit)]
{
    // Attributes available to this derive:
    #[spongefish]
}

Derive Units for structs.

use spongefish::Unit;

#[derive(Clone, Unit)]
struct Rgb {
    r: u8,
    g: u8,
    b: u8,
}

assert_eq!((Rgb::ZERO.r, Rgb::ZERO.g, Rgb::ZERO.b), (0, 0, 0));