Define get_inner_ty because this function includes '?' operator

Author: long-long-float

compiler/rustc_hir/src/hir.rs

@@ -662,22 +662,24 @@ impl<'hir> Generics<'hir> {
         &self,
         param_def_id: LocalDefId,
     ) -> Option<(Span, bool)> {
-        self.bounds_for_param(param_def_id).flat_map(|bp| bp.bounds.iter().rev()).find_map(
-            |bound| {
-                let inner_ty = match bound {
-                    GenericBound::Trait(data, _) => {
-                        let segment = data.trait_ref.path.segments.first()?;
-                        let binding = segment.args().bindings.first()?;
-                        if let TypeBindingKind::Equality { term: Term::Ty(ty) } = binding.kind {
-                            Some(ty)
-                        } else {
-                            None
-                        }
+        fn get_inner_ty<'a, 'b>(bound: &'a GenericBound<'b>) -> Option<&'a Ty<'b>> {
+            match bound {
+                GenericBound::Trait(data, _) => {
+                    let segment = data.trait_ref.path.segments.first()?;
+                    let binding = segment.args().bindings.first()?;
+                    if let TypeBindingKind::Equality { term: Term::Ty(ty) } = binding.kind {
+                        Some(ty)
+                    } else {
+                        None
                     }
-                    _ => None,
-                };
+                }
+                _ => None,
+            }
+        }
 
-                let span_for_parentheses = inner_ty.and_then(|ty| {
+        self.bounds_for_param(param_def_id).flat_map(|bp| bp.bounds.iter().rev()).find_map(
+            |bound| {
+                let span_for_parentheses = get_inner_ty(bound).and_then(|ty| {
                     if let TyKind::TraitObject(_, _, TraitObjectSyntax::Dyn) = ty.kind {
                         let span = ty.span;
                         span.can_be_used_for_suggestions().then(|| span)