1 files changed, 14 insertions, 0 deletions
diff --git a/tests/ui/regions/higher-ranked-implied.rs b/tests/ui/regions/higher-ranked-implied.rs
new file mode 100644
index 000000000..103884c50
--- /dev/null
+++ b/tests/ui/regions/higher-ranked-implied.rs
@@ -0,0 +1,14 @@
+// FIXME: This test should pass as the first two fields add implied bounds that
+// `'a` is equal to `'b` while the last one should simply use that fact. With
+// the current implementation this errors. We have to be careful as implied bounds
+// are only sound if they're also correctly checked.
+
+struct Inv<T>(*mut T); // `T` is invariant.
+type A = for<'a, 'b> fn(Inv<&'a &'b ()>, Inv<&'b &'a ()>, Inv<&'a ()>);
+type B = for<'a, 'b> fn(Inv<&'a &'b ()>, Inv<&'b &'a ()>, Inv<&'b ()>);
+
+fn main() {
+    let x: A = |_, _, _| ();
+    let y: B = x; //~ ERROR mismatched types
+    let _: A = y; //~ ERROR mismatched types
+}