Code shared from the Rust Playground

reorder.rs

#![allow(unused)]

fn reorder<T: Clone>(values: Vec<T>, indices: Vec<usize>) -> Vec<Option<(usize, T)>> {
    let mut pairs: Vec<_> = indices.iter().zip(values).collect();
    pairs.sort_by_key(|v| v.0);

    let mut iter = pairs.iter().peekable();
    (0..*pairs.last().unwrap().0 + 1)
        .map(|i| match iter.peek() {
            Some((j, _)) => {
                if i == **j {
                    Some((i, iter.next().unwrap().1.clone()))
                } else {
                    None
                }
            }
            None => None,
        })
        .collect()
}

#[test]
fn reorder_all_indices() {
    let values = vec!["C", "D", "E", "F", "G", "H"];
    let indices = vec![3, 0, 4, 1, 2, 5];

    let mut reordered = reorder(values, indices);
    assert_eq!(Some((0, "D")), reordered[0]);
    assert_eq!(Some((1, "F")), reordered[1]);
    assert_eq!(Some((2, "G")), reordered[2]);
    assert_eq!(Some((3, "C")), reordered[3]);
    assert_eq!(Some((4, "E")), reordered[4]);
    assert_eq!(Some((5, "H")), reordered[5]);
}

#[test]
fn reorder_missing_indices() {
    let values = vec!["C", "D", "E", "F"];
    let indices = vec![4, 0, 1, 5];

    let mut reordered = reorder(values, indices);
    assert_eq!(Some((0, "D")), reordered[0]);
    assert_eq!(Some((1, "E")), reordered[1]);
    assert_eq!(None, reordered[2]);
    assert_eq!(None, reordered[3]);
    assert_eq!(Some((4, "C")), reordered[4]);
    assert_eq!(Some((5, "F")), reordered[5]);
}