1 files changed, 26 insertions, 0 deletions
diff --git a/src/test/ui/rfc-2632-const-trait-impl/specializing-constness.rs b/src/test/ui/rfc-2632-const-trait-impl/specializing-constness.rs
new file mode 100644
index 000000000..ff0cd489d
--- /dev/null
+++ b/src/test/ui/rfc-2632-const-trait-impl/specializing-constness.rs
@@ -0,0 +1,26 @@
+#![feature(const_trait_impl, min_specialization, rustc_attrs)]
+
+#[rustc_specialization_trait]
+#[const_trait]
+pub trait Sup {}
+
+impl const Sup for () {}
+
+#[const_trait]
+pub trait A {
+    fn a() -> u32;
+}
+
+impl<T: ~const Default> const A for T {
+    default fn a() -> u32 {
+        2
+    }
+}
+
+impl<T: Default + Sup> A for T { //~ ERROR: cannot specialize
+    fn a() -> u32 {
+        3
+    }
+}
+
+fn main() {}