//@ known-bug: #131342
// see also: 131342-2.rs

fn main() {
  let mut items = vec![1, 2, 3, 4, 5].into_iter();
  problem_thingy(&mut items);
}

fn problem_thingy(items: &mut impl Iterator<Item = u8>) {
  let mut peeker = items.peekable();
  match peeker.peek() {
    Some(_) => (),
    None => return (),
  }
  problem_thingy(&mut peeker);
}