1 files changed, 64 insertions, 0 deletions
diff --git a/src/test/ui/traits/typeclasses-eq-example.rs b/src/test/ui/traits/typeclasses-eq-example.rs
new file mode 100644
index 000000000..4400301e6
--- /dev/null
+++ b/src/test/ui/traits/typeclasses-eq-example.rs
@@ -0,0 +1,64 @@
+// run-pass
+
+#![allow(non_camel_case_types)]
+#![allow(non_snake_case)]
+#![allow(dead_code)]
+
+// Example from lkuper's intern talk, August 2012.
+use Color::{cyan, magenta, yellow, black};
+use ColorTree::{leaf, branch};
+
+trait Equal {
+    fn isEq(&self, a: &Self) -> bool;
+}
+
+#[derive(Clone, Copy)]
+enum Color { cyan, magenta, yellow, black }
+
+impl Equal for Color {
+    fn isEq(&self, a: &Color) -> bool {
+        match (*self, *a) {
+          (cyan, cyan)       => { true  }
+          (magenta, magenta) => { true  }
+          (yellow, yellow)   => { true  }
+          (black, black)     => { true  }
+          _                  => { false }
+        }
+    }
+}
+
+#[derive(Clone)]
+enum ColorTree {
+    leaf(Color),
+    branch(Box<ColorTree>, Box<ColorTree>)
+}
+
+impl Equal for ColorTree {
+    fn isEq(&self, a: &ColorTree) -> bool {
+        match (self, a) {
+          (&leaf(ref x), &leaf(ref y)) => { x.isEq(&(*y).clone()) }
+          (&branch(ref l1, ref r1), &branch(ref l2, ref r2)) => {
+            (*l1).isEq(&(**l2).clone()) && (*r1).isEq(&(**r2).clone())
+          }
+          _ => { false }
+        }
+    }
+}
+
+pub fn main() {
+    assert!(cyan.isEq(&cyan));
+    assert!(magenta.isEq(&magenta));
+    assert!(!cyan.isEq(&yellow));
+    assert!(!magenta.isEq(&cyan));
+
+    assert!(leaf(cyan).isEq(&leaf(cyan)));
+    assert!(!leaf(cyan).isEq(&leaf(yellow)));
+
+    assert!(branch(Box::new(leaf(magenta)), Box::new(leaf(cyan)))
+        .isEq(&branch(Box::new(leaf(magenta)), Box::new(leaf(cyan)))));
+
+    assert!(!branch(Box::new(leaf(magenta)), Box::new(leaf(cyan)))
+        .isEq(&branch(Box::new(leaf(magenta)), Box::new(leaf(magenta)))));
+
+    println!("Assertions all succeeded!");
+}