1 files changed, 21 insertions, 0 deletions
diff --git a/src/test/ui/generic-associated-types/const-generics-gat-in-trait-return-type-1.rs b/src/test/ui/generic-associated-types/const-generics-gat-in-trait-return-type-1.rs
new file mode 100644
index 000000000..afde5f376
--- /dev/null
+++ b/src/test/ui/generic-associated-types/const-generics-gat-in-trait-return-type-1.rs
@@ -0,0 +1,21 @@
+// run-pass
+#![feature(generic_associated_types)]
+
+// This test unsures that with_opt_const_param returns the
+// def_id of the N param in the Foo::Assoc GAT.
+
+trait Foo {
+    type Assoc<const N: usize>;
+    fn foo(&self) -> Self::Assoc<3>;
+}
+
+impl Foo for () {
+    type Assoc<const N: usize> = [(); N];
+    fn foo(&self) -> Self::Assoc<3> {
+        [(); 3]
+    }
+}
+
+fn main() {
+    assert_eq!(().foo(), [(); 3]);
+}