Simple quicksort in rust

qsort.rs

fn qs<T: std::cmp::Ord>(a: &mut [T]) {
    if a.len() <= 1 { return; }

    let last_index = a.len() - 1; // pivot index
    let mut partition_index = 0;
    for i in 0..last_index {
        if a[i] >= a[last_index] { continue; }

        a.swap(i, partition_index);
        partition_index += 1;
    }
    a.swap(partition_index, last_index);

    qs(&mut a[0..partition_index]);
    qs(&mut a[(partition_index + 1)..=last_index]);
}

fn main() {
    let mut a = [-1,0,-2,5,7,0,-6,1];
    qs(&mut a);
    println!("{:?}", a);
}