Derive Macro Enum 

#[derive(Enum)]
{
    // Attributes available to this derive:
    #[enumtag]
}

use std::num::NonZero;

use object_rainbow::{Enum, MaybeHasNiche, ToOutput};

#[derive(Enum, ToOutput, MaybeHasNiche)]
enum WithDefault {
    A(u8),
    B(bool),
}

assert_eq!(Some(WithDefault::A(32)).vec(), [0, 32]);
assert_eq!(Some(WithDefault::B(true)).vec(), [1, 1]);
assert_eq!(None::<WithDefault>.vec(), [2, 0]);

#[derive(Enum, ToOutput, MaybeHasNiche)]
#[enumtag("NonZero<u8>")]
enum WithNz {
    A(u8),
    B(bool),
}

assert_eq!(None::<WithNz>.vec(), [0, 0]);
assert_eq!(Some(WithNz::A(32)).vec(), [1, 32]);
assert_eq!(Some(WithNz::B(true)).vec(), [2, 1]);

#[derive(Enum, ToOutput, MaybeHasNiche)]
#[enumtag("bool")]
enum WithBool {
    A(u8),
    B(bool),
}

assert_eq!(Some(WithBool::A(32)).vec(), [0, 32]);
assert_eq!(Some(WithBool::B(true)).vec(), [1, 1]);
assert_eq!(None::<WithBool>.vec(), [2, 0]);

#[derive(Enum, ToOutput, MaybeHasNiche)]
#[enumtag("u8")]
enum WithU8 {
    A(u8),
    B(bool),
}

assert_eq!(Some(WithU8::A(32)).vec(), [0, 32]);
assert_eq!(Some(WithU8::B(true)).vec(), [1, 1]);
assert_eq!(None::<WithU8>.vec(), [1, 2]);

#[derive(Enum, ToOutput, MaybeHasNiche)]
#[enumtag("u8")]
enum WithoutNiche {
    A(u8),
    B(u8),
}

assert_eq!(Some(WithoutNiche::A(32)).vec(), [0, 0, 32]);
assert_eq!(Some(WithoutNiche::B(1)).vec(), [0, 1, 1]);
assert_eq!(None::<WithoutNiche>.vec(), [1]);