Cleanup assoc parent utils

1 files changed, 7 insertions, 6 deletions

diff --git a/compiler/rustc_monomorphize/src/partitioning.rs b/compiler/rustc_monomorphize/src/partitioning.rs
index d76b27d9970..54d77b182f8 100644
--- a/compiler/rustc_monomorphize/src/partitioning.rs
+++ b/compiler/rustc_monomorphize/src/partitioning.rs
@@ -650,17 +650,18 @@ fn characteristic_def_id_of_mono_item<'tcx>(
             // its self-type. If the self-type does not provide a characteristic
             // DefId, we use the location of the impl after all.
 
-            if tcx.trait_of_assoc(def_id).is_some() {
+            let assoc_parent = tcx.assoc_parent(def_id);
+
+            if let Some((_, DefKind::Trait)) = assoc_parent {
                 let self_ty = instance.args.type_at(0);
                 // This is a default implementation of a trait method.
                 return characteristic_def_id_of_type(self_ty).or(Some(def_id));
             }
 
-            if let Some(impl_def_id) = tcx.impl_of_assoc(def_id) {
-                if tcx.sess.opts.incremental.is_some()
-                    && tcx
-                        .trait_id_of_impl(impl_def_id)
-                        .is_some_and(|def_id| tcx.is_lang_item(def_id, LangItem::Drop))
+            if let Some((impl_def_id, DefKind::Impl { of_trait })) = assoc_parent {
+                if of_trait
+                    && tcx.sess.opts.incremental.is_some()
+                    && tcx.is_lang_item(tcx.trait_id_of_impl(impl_def_id).unwrap(), LangItem::Drop)
                 {
                     // Put `Drop::drop` into the same cgu as `drop_in_place`
                     // since `drop_in_place` is the only thing that can