1 files changed, 58 insertions, 0 deletions
diff --git a/tests/ui/rfcs/rfc-2632-const-trait-impl/specialization/const-default-bound-non-const-specialized-bound.rs b/tests/ui/rfcs/rfc-2632-const-trait-impl/specialization/const-default-bound-non-const-specialized-bound.rs
new file mode 100644
index 000000000..f31123f16
--- /dev/null
+++ b/tests/ui/rfcs/rfc-2632-const-trait-impl/specialization/const-default-bound-non-const-specialized-bound.rs
@@ -0,0 +1,58 @@
+// Tests that trait bounds on specializing trait impls must be `~const` if the
+// same bound is present on the default impl and is `~const` there.
+
+#![feature(const_trait_impl)]
+#![feature(rustc_attrs)]
+#![feature(min_specialization)]
+
+#[rustc_specialization_trait]
+trait Specialize {}
+
+#[const_trait]
+trait Foo {}
+
+#[const_trait]
+trait Bar {
+    fn bar();
+}
+
+// bgr360: I was only able to exercise the code path that raises the
+// "missing ~const qualifier" error by making this base impl non-const, even
+// though that doesn't really make sense to do. As seen below, if the base impl
+// is made const, rustc fails earlier with an overlapping impl failure.
+impl<T> Bar for T
+where
+    T: ~const Foo,
+{
+    default fn bar() {}
+}
+
+impl<T> Bar for T
+where
+    T: Foo, //~ ERROR missing `~const` qualifier
+    T: Specialize,
+{
+    fn bar() {}
+}
+
+#[const_trait]
+trait Baz {
+    fn baz();
+}
+
+impl<T> const Baz for T
+where
+    T: ~const Foo,
+{
+    default fn baz() {}
+}
+
+impl<T> const Baz for T //~ ERROR conflicting implementations of trait `Baz`
+where
+    T: Foo,
+    T: Specialize,
+{
+    fn baz() {}
+}
+
+fn main() {}