1 files changed, 28 insertions, 0 deletions
diff --git a/src/test/ui/traits/inheritance/diamond.rs b/src/test/ui/traits/inheritance/diamond.rs
new file mode 100644
index 000000000..32ad0fb4d
--- /dev/null
+++ b/src/test/ui/traits/inheritance/diamond.rs
@@ -0,0 +1,28 @@
+// run-pass
+#![allow(dead_code)]
+// B and C both require A, so D does as well, twice, but that's just fine
+
+
+trait A { fn a(&self) -> isize; }
+trait B: A { fn b(&self) -> isize; }
+trait C: A { fn c(&self) -> isize; }
+trait D: B + C { fn d(&self) -> isize; }
+
+struct S { bogus: () }
+
+impl A for S { fn a(&self) -> isize { 10 } }
+impl B for S { fn b(&self) -> isize { 20 } }
+impl C for S { fn c(&self) -> isize { 30 } }
+impl D for S { fn d(&self) -> isize { 40 } }
+
+fn f<T:D>(x: &T) {
+    assert_eq!(x.a(), 10);
+    assert_eq!(x.b(), 20);
+    assert_eq!(x.c(), 30);
+    assert_eq!(x.d(), 40);
+}
+
+pub fn main() {
+    let value = &S { bogus: () };
+    f(value);
+}