1 files changed, 25 insertions, 0 deletions

diff --git a/tests/ui/issues/issue-10456.rs b/tests/ui/issues/issue-10456.rs
new file mode 100644
index 00000000000..9f8d2595520
--- /dev/null
+++ b/tests/ui/issues/issue-10456.rs
@@ -0,0 +1,25 @@
+// check-pass
+// pretty-expanded FIXME #23616
+
+pub struct Foo;
+
+pub trait Bar {
+    fn bar(&self);
+}
+
+pub trait Baz {
+    fn baz(&self) { }
+}
+
+impl<T: Baz> Bar for T {
+    fn bar(&self) {}
+}
+
+impl Baz for Foo {}
+
+pub fn foo(t: Box<Foo>) {
+    t.bar(); // ~Foo doesn't implement Baz
+    (*t).bar(); // ok b/c Foo implements Baz
+}
+
+fn main() {}