1 files changed, 26 insertions, 0 deletions
diff --git a/src/test/ui/extern/extern-types-trait-impl.rs b/src/test/ui/extern/extern-types-trait-impl.rs
new file mode 100644
index 000000000..656101ed5
--- /dev/null
+++ b/src/test/ui/extern/extern-types-trait-impl.rs
@@ -0,0 +1,26 @@
+// run-pass
+#![allow(dead_code)]
+// Test that traits can be implemented for extern types.
+#![feature(extern_types)]
+
+extern "C" {
+    type A;
+}
+
+trait Foo {
+    fn foo(&self) {}
+}
+
+impl Foo for A {
+    fn foo(&self) {}
+}
+
+fn assert_foo<T: ?Sized + Foo>() {}
+
+fn use_foo<T: ?Sized + Foo>(x: &dyn Foo) {
+    x.foo();
+}
+
+fn main() {
+    assert_foo::<A>();
+}