if mut_ty.mutbl == Mutability::Not;
if let TyKind::Path(ref qpath) = &mut_ty.ty.kind;
let last = last_path_segment(qpath);
- if let Some(res) = last.res;
- if let Some(def_id) = res.opt_def_id();
+ if let Some(def_id) = last.res.opt_def_id();
if cx.tcx.is_diagnostic_item(sym::Option, def_id);
if let Some(params) = last_path_segment(qpath).args ;