// run-pass
pub fn main() {
let mut tups = vec![(0u8, 1u8)];
for (n, m) in &tups {
let _: &u8 = n;
let _: &u8 = m;
}
for (n, m) in &mut tups {
*n += 1;
*m += 2;
assert_eq!(tups, vec![(1u8, 3u8)]);
for (n, m) in tups {
println!("{} {}", m, n);