Implement passing cast-to-vtable values as bounded params

Closes #1492

1 files changed, 5 insertions, 1 deletions

diff --git a/src/test/run-pass/iface-cast.rs b/src/test/run-pass/iface-cast.rs
index 05da479f864..f252eef07bc 100644
--- a/src/test/run-pass/iface-cast.rs
+++ b/src/test/run-pass/iface-cast.rs
@@ -33,6 +33,8 @@ impl of to_str for Tree {
     }
 }
 
+fn foo<T: to_str>(x: T) -> str { x.to_str() }
+
 fn main() {
     let t1 = Tree(@{mutable left: none,
                     mutable right: none,
@@ -40,6 +42,8 @@ fn main() {
     let t2 = Tree(@{mutable left: some(t1),
                     mutable right: some(t1),
                     val: 2 as to_str });
-    assert t2.to_str() == "[2, some([1, none, none]), some([1, none, none])]";
+    let expected = "[2, some([1, none, none]), some([1, none, none])]";
+    assert t2.to_str() == expected;
+    assert foo(t2 as to_str) == expected;
     t1.left = some(t2); // create cycle
 }