assert!(head.len() + tail.len() <= 8);
let mut gs = [0u16; 8];
gs.clone_from_slice(head);
- gs.slice_mut(8 - tail.len(), 8).clone_from_slice(tail);
+ gs[(8 - tail.len()) .. 8].clone_from_slice(tail);
Ipv6Addr(gs[0], gs[1], gs[2], gs[3], gs[4], gs[5], gs[6], gs[7])
}