Crate ord_by

OrdBy

Conveniently attach a custom compare function to any type, to get sort_by() type behavior from types like BinaryHeap

OrdBy is a generalization of the pattern used by Reverse.

use std::collections::BinaryHeap;
use ord_by::*;

let numbers = vec![0, 2, 4, 6, 8, 1, 3, 5, 7, 9];
let mut heap = BinaryHeap::with_capacity(10);

numbers.into_iter().ord_by(|a, b| a.cmp(b))
    .for_each(|n| heap.push(n));

let mut sorted = Vec::with_capacity(10);
while let Some(n) = heap.pop() {
    sorted.push(n.into_inner())
}

assert_eq!(sorted, vec![9, 8, 7, 6, 5, 4, 3, 2, 1, 0])

Future Work: I would like the compare function to be a single associated constant for efficiency, rather than being a variable stored with each struct instance. However that requires associated constants that can have a type dependent on generics, which is currently an unsupported feature. https://github.com/rust-lang/rust/issues/98210

Structs

OrdBy

A wrapper around a type, that implements the Ord trait in terms of the F function

OrdByIter

An Iterator returned by OrdByIterTrait::ord_by

Traits

OrdByIterTrait

A trait for any Iterator exposing the OrdByIterTrait::ord_by method