struct X(Vec<u8>);

impl Drop for X {
    fn drop(&mut self) {}
}

fn main() {
  let mut x = Some(X(vec![4]));

  match &mut x {
    Some(X(list)) => {
        let list = std::mem::replace(list, Vec::new());
        println!("{:?}", list);
        // i want to own list here, not clone it
    }
    None => {}
  }
}