// Ensure there is at most one `self` in the list
let self_spans = items
.iter()
- .filter_map(|&(ref use_tree, _)| {
+ .filter_map(|(use_tree, _)| {
if let ast::UseTreeKind::Simple(..) = use_tree.kind {
if use_tree.ident().name == kw::SelfLower {
return Some(use_tree.span);