fix nit

compiler/rustc_typeck/src/expr_use_visitor.rs

@@ -272,9 +272,15 @@ impl<'a, 'tcx> ExprUseVisitor<'a, 'tcx> {
                                 // to borrow discr.
                                 needs_to_be_read = true;
                             }
-                            _ => {
+                            PatKind::Or(_)
+                            | PatKind::Box(_)
+                            | PatKind::Slice(..)
+                            | PatKind::Ref(..)
+                            | PatKind::Wild => {
                                 // If the PatKind is Or, Box, Slice or Ref, the decision is made later
                                 // as these patterns contains subpatterns
+                                // If the PatKind is Wild, the decision is made based on the other patterns being
+                                // examined
                             }
                         }
                     }));