Propagate errors rather than using return_if_err

clippy_utils/src/lib.rs

@@ -7,6 +7,7 @@
 #![feature(never_type)]
 #![feature(rustc_private)]
 #![feature(assert_matches)]
+#![feature(unwrap_infallible)]
 #![recursion_limit = "512"]
 #![cfg_attr(feature = "deny-warnings", deny(warnings))]
 #![allow(

clippy_utils/src/sugg.rs

@@ -830,7 +830,9 @@ pub fn deref_closure_args(cx: &LateContext<'_>, closure: &hir::Expr<'_>) -> Opti
             applicability: Applicability::MachineApplicable,
         };
 
-        ExprUseVisitor::for_clippy(cx, def_id, &mut visitor).consume_body(closure_body);
+        ExprUseVisitor::for_clippy(cx, def_id, &mut visitor)
+            .consume_body(closure_body)
+            .into_ok();
 
         if !visitor.suggestion_start.is_empty() {
             return Some(DerefClosure {

clippy_utils/src/usage.rs

@@ -21,7 +21,8 @@ pub fn mutated_variables<'tcx>(expr: &'tcx Expr<'_>, cx: &LateContext<'tcx>) ->
         expr.hir_id.owner.def_id,
         &mut delegate,
     )
-    .walk_expr(expr);
+    .walk_expr(expr)
+    .into_ok();
 
     if delegate.skip {
         return None;