cmporder 0.1.1

macros for prioritized Ord/PartialOrd
Documentation 
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use cmporder::{cmp_order, partial_cmp_order};
use rand::seq::SliceRandom;

#[test]
fn test_cmporder() {
    #[derive(Debug, Clone, Copy, PartialEq, Eq)]
    struct ABC {
        a: u8,
        b: u8,
    }

    impl Ord for ABC {
        fn cmp(&self, other: &Self) -> std::cmp::Ordering {
            // priority:
            // 1) a
            // 2) b%2
            // 3) b
            cmp_order!(
                self.a.cmp(&other.a),
                (self.b % 2).cmp(&(other.b % 2)),
                self.b.cmp(&other.b),
            )
        }
    }

    impl PartialOrd for ABC {
        fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
            Some(self.cmp(other))
        }
    }

    let abc1 = ABC { a: 10, b: 20 };
    let abc2 = ABC { a: 20, b: 10 };
    let abc3 = ABC { a: 10, b: 11 };

    let list = vec![abc1, abc2, abc3];

    let mut rng = rand::rng();
    let mut list = list.clone();
    list.shuffle(&mut rng);

    list.sort();
    assert_eq!(list, vec![abc1, abc3, abc2]);
}

#[test]
fn test_partial_cmporder() {
    #[derive(Debug, Clone, Copy, PartialEq, Eq)]
    struct ABC {
        a: u8,
        b: u8,
    }

    impl PartialOrd for ABC {
        fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
            // priority:
            // 1) a
            // 2) b%2
            // 3) b
            partial_cmp_order!(
                self.a.partial_cmp(&other.a),
                Some((self.b % 2).cmp(&(other.b % 2))),
                self.b.partial_cmp(&other.b)
            )
        }
    }

    impl Ord for ABC {
        fn cmp(&self, other: &Self) -> std::cmp::Ordering {
            self.partial_cmp(other).unwrap_or(std::cmp::Ordering::Equal)
        }
    }

    let abc1 = ABC { a: 20, b: 20 };
    let abc2 = ABC { a: 20, b: 11 };
    let abc3 = ABC { a: 10, b: 20 };

    let list = vec![abc1, abc2, abc3];

    let mut rng = rand::rng();
    let mut list = list.clone();
    list.shuffle(&mut rng);

    list.sort();
    assert_eq!(list, vec![abc3, abc1, abc2]);
}