diag: &mut Diagnostic,
) {
if !self_ty.needs_subst() {
- let mut_key = if ptr_ty.mutbl == rustc_middle::mir::Mutability::Mut { "mut " } else { "" };
+ let mut_key = ptr_ty.mutbl.prefix_str();
let msg_sugg = "consider introducing a new wrapper type".to_owned();
let sugg = vec![
(