1 files changed, 21 insertions, 0 deletions
diff --git a/src/test/ui/type-alias-impl-trait/issue-66580-closure-coherence.rs b/src/test/ui/type-alias-impl-trait/issue-66580-closure-coherence.rs
new file mode 100644
index 000000000..d97270c31
--- /dev/null
+++ b/src/test/ui/type-alias-impl-trait/issue-66580-closure-coherence.rs
@@ -0,0 +1,21 @@
+// Regression test for issue #66580
+// Ensures that we don't try to determine whether a closure
+// is foreign when it's the underlying type of an opaque type
+// check-pass
+#![feature(type_alias_impl_trait)]
+
+type Closure = impl FnOnce();
+
+fn closure() -> Closure {
+    || {}
+}
+
+struct Wrap<T> {
+    f: T,
+}
+
+impl Wrap<Closure> {}
+
+impl<T> Wrap<T> {}
+
+fn main() {}