Shared via Rust Playground

playground.rs

fn filter<T>(res: &mut [usize], lhs: &[T], rhs: &[T]) 
   where T : Copy + PartialOrd {

  let mut matched: usize = 0;
  
  for x in 0..lhs.len() {
    res[matched] = x;
    matched = matched + if lhs[x] > rhs[x] { 1 } else { 0 };
  }
}


fn main() {
  let mut res: [usize;4] = [0,0,0,0];
  let lhs: [i32;4] = [1,2,3,4];
  let rhs: [i32;4] = [5,6,7,8];
  
  filter(&mut res, &lhs, &rhs);
  
  for x in 0..res.len() {
    println!("{}", res[x]);
  }
}