Only match on the DefKind once.

Author: oli-obk

compiler/rustc_ty_utils/src/opaque_types.rs

@@ -268,41 +268,31 @@ fn opaque_types_defined_by<'tcx>(tcx: TyCtxt<'tcx>, item: LocalDefId) -> &'tcx [
     trace!(?kind);
     let mut collector = OpaqueTypeCollector::new(tcx, item);
     match kind {
-        // We're also doing this for `AssocTy` for the wf checks in `check_opaque_meets_bounds`
+        // Walk over the signature of the function-like to find the opaques.
+        DefKind::AssocFn | DefKind::Fn => {
+            let ty_sig = tcx.fn_sig(item).subst_identity();
+            let hir_sig = tcx.hir().get_by_def_id(item).fn_sig().unwrap();
+            // Walk over the inputs and outputs manually in order to get good spans for them.
+            collector.visit_spanned(hir_sig.decl.output.span(), ty_sig.output());
+            for (hir, ty) in hir_sig.decl.inputs.iter().zip(ty_sig.inputs().iter()) {
+                collector.visit_spanned(hir.span, ty.map_bound(|x| *x));
+            }
+            collector.collect_body_and_predicate_taits();
+        }
+        // Walk over the type of the item to find opaques.
         DefKind::Static(_)
         | DefKind::Const
         | DefKind::AssocConst
-        | DefKind::AssocFn
         | DefKind::AnonConst
-        | DefKind::InlineConst
-        | DefKind::Fn => {
-            match kind {
-                // Walk over the signature of the function-like to find the opaques.
-                DefKind::AssocFn | DefKind::Fn => {
-                    let ty_sig = tcx.fn_sig(item).subst_identity();
-                    let hir_sig = tcx.hir().get_by_def_id(item).fn_sig().unwrap();
-                    // Walk over the inputs and outputs manually in order to get good spans for them.
-                    collector.visit_spanned(hir_sig.decl.output.span(), ty_sig.output());
-                    for (hir, ty) in hir_sig.decl.inputs.iter().zip(ty_sig.inputs().iter()) {
-                        collector.visit_spanned(hir.span, ty.map_bound(|x| *x));
-                    }
-                }
-                // Walk over the type of the item to find opaques.
-                DefKind::Static(_)
-                | DefKind::Const
-                | DefKind::AssocConst
-                | DefKind::AnonConst
-                | DefKind::InlineConst => {
-                    let span = match tcx.hir().get_by_def_id(item).ty() {
-                        Some(ty) => ty.span,
-                        _ => tcx.def_span(item),
-                    };
-                    collector.visit_spanned(span, tcx.type_of(item).subst_identity());
-                }
-                _ => unreachable!(),
-            }
+        | DefKind::InlineConst => {
+            let span = match tcx.hir().get_by_def_id(item).ty() {
+                Some(ty) => ty.span,
+                _ => tcx.def_span(item),
+            };
+            collector.visit_spanned(span, tcx.type_of(item).subst_identity());
             collector.collect_body_and_predicate_taits();
         }
+        // We're also doing this for `AssocTy` for the wf checks in `check_opaque_meets_bounds`
         DefKind::TyAlias | DefKind::AssocTy => {
             tcx.type_of(item).subst_identity().visit_with(&mut collector);
         }