1 files changed, 16 insertions, 0 deletions
diff --git a/src/test/ui/associated-types/issue-43924.rs b/src/test/ui/associated-types/issue-43924.rs
new file mode 100644
index 000000000..6a63b3e09
--- /dev/null
+++ b/src/test/ui/associated-types/issue-43924.rs
@@ -0,0 +1,16 @@
+#![feature(associated_type_defaults)]
+
+// This used to cause an ICE because assoc. type defaults weren't properly
+// type-checked.
+
+trait Foo<T: Default + ToString> {
+    type Out: Default + ToString + ?Sized = dyn ToString;  //~ ERROR not satisfied
+}
+
+impl Foo<u32> for () {}
+impl Foo<u64> for () {}
+
+fn main() {
+    assert_eq!(<() as Foo<u32>>::Out::default().to_string(), "false");
+    //~^ ERROR no function or associated item named `default` found for trait object
+}