Allow specializing on const trait bounds

1 files changed, 55 insertions, 0 deletions

diff --git a/src/test/ui/specialization/const_trait_impl.rs b/src/test/ui/specialization/const_trait_impl.rs
new file mode 100644
index 00000000000..05ba4c8d45d
--- /dev/null
+++ b/src/test/ui/specialization/const_trait_impl.rs
@@ -0,0 +1,55 @@
+// check-pass
+#![feature(const_trait_impl, min_specialization, rustc_attrs)]
+
+#[rustc_specialization_trait]
+#[const_trait]
+pub unsafe trait Sup {
+    fn foo() -> u32;
+}
+
+#[rustc_specialization_trait]
+#[const_trait]
+pub unsafe trait Sub: ~const Sup {}
+
+unsafe impl const Sup for u8 {
+    default fn foo() -> u32 {
+        1
+    }
+}
+
+unsafe impl const Sup for () {
+    fn foo() -> u32 {
+        42
+    }
+}
+
+unsafe impl const Sub for () {}
+
+#[const_trait]
+pub trait A {
+    fn a() -> u32;
+}
+
+impl<T: ~const Default> const A for T {
+    default fn a() -> u32 {
+        2
+    }
+}
+
+impl<T: ~const Default + ~const Sup> const A for T {
+    default fn a() -> u32 {
+        3
+    }
+}
+
+impl<T: ~const Default + ~const Sub> const A for T {
+    fn a() -> u32 {
+        T::foo()
+    }
+}
+
+const _: () = assert!(<()>::a() == 42);
+const _: () = assert!(<u8>::a() == 3);
+const _: () = assert!(<u16>::a() == 2);
+
+fn main() {}