1 files changed, 15 insertions, 0 deletions
diff --git a/tests/ui/lint/unused/trait-alias-supertrait.rs b/tests/ui/lint/unused/trait-alias-supertrait.rs
new file mode 100644
index 000000000..46f00c06b
--- /dev/null
+++ b/tests/ui/lint/unused/trait-alias-supertrait.rs
@@ -0,0 +1,15 @@
+// check-pass
+
+// Make sure that we only consider *Self* supertrait predicates
+// in the `unused_must_use` lint.
+
+#![feature(trait_alias)]
+#![deny(unused_must_use)]
+
+trait Foo<T> = Sized where T: Iterator;
+
+fn test<T: Iterator>() -> impl Foo<T> {}
+
+fn main() {
+    test::<std::iter::Once<()>>();
+}