1 files changed, 29 insertions, 0 deletions
diff --git a/src/test/ui/traits/inheritance/auto.rs b/src/test/ui/traits/inheritance/auto.rs
new file mode 100644
index 000000000..0be67a55e
--- /dev/null
+++ b/src/test/ui/traits/inheritance/auto.rs
@@ -0,0 +1,29 @@
+// run-pass
+#![allow(dead_code)]
+// Testing that this impl turns A into a Quux, because
+// A is already a Foo Bar Baz
+
+impl<T:Foo + Bar + Baz> Quux for T { }
+
+trait Foo { fn f(&self) -> isize; }
+trait Bar { fn g(&self) -> isize; }
+trait Baz { fn h(&self) -> isize; }
+
+trait Quux: Foo + Bar + Baz { }
+
+struct A { x: isize }
+
+impl Foo for A { fn f(&self) -> isize { 10 } }
+impl Bar for A { fn g(&self) -> isize { 20 } }
+impl Baz for A { fn h(&self) -> isize { 30 } }
+
+fn f<T:Quux>(a: &T) {
+    assert_eq!(a.f(), 10);
+    assert_eq!(a.g(), 20);
+    assert_eq!(a.h(), 30);
+}
+
+pub fn main() {
+    let a = &A { x: 3 };
+    f(a);
+}