summaryrefslogtreecommitdiffstats
path: root/src/test/ui/traits/typeclasses-eq-example-static.rs
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--src/test/ui/traits/typeclasses-eq-example-static.rs68
1 files changed, 68 insertions, 0 deletions
diff --git a/src/test/ui/traits/typeclasses-eq-example-static.rs b/src/test/ui/traits/typeclasses-eq-example-static.rs
new file mode 100644
index 000000000..f982ad6a0
--- /dev/null
+++ b/src/test/ui/traits/typeclasses-eq-example-static.rs
@@ -0,0 +1,68 @@
+// run-pass
+
+#![allow(non_camel_case_types)]
+#![allow(non_snake_case)]
+#![allow(dead_code)]
+
+// Example from lkuper's intern talk, August 2012 -- now with static
+// methods!
+use Color::{cyan, magenta, yellow, black};
+use ColorTree::{leaf, branch};
+
+trait Equal {
+ fn isEq(a: &Self, b: &Self) -> bool;
+}
+
+#[derive(Clone, Copy)]
+enum Color { cyan, magenta, yellow, black }
+
+impl Equal for Color {
+ fn isEq(a: &Color, b: &Color) -> bool {
+ match (*a, *b) {
+ (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(a: &ColorTree, b: &ColorTree) -> bool {
+ match (a, b) {
+ (&leaf(ref x), &leaf(ref y)) => {
+ Equal::isEq(&(*x).clone(), &(*y).clone())
+ }
+ (&branch(ref l1, ref r1), &branch(ref l2, ref r2)) => {
+ Equal::isEq(&(**l1).clone(), &(**l2).clone()) &&
+ Equal::isEq(&(**r1).clone(), &(**r2).clone())
+ }
+ _ => { false }
+ }
+ }
+}
+
+pub fn main() {
+ assert!(Equal::isEq(&cyan, &cyan));
+ assert!(Equal::isEq(&magenta, &magenta));
+ assert!(!Equal::isEq(&cyan, &yellow));
+ assert!(!Equal::isEq(&magenta, &cyan));
+
+ assert!(Equal::isEq(&leaf(cyan), &leaf(cyan)));
+ assert!(!Equal::isEq(&leaf(cyan), &leaf(yellow)));
+
+ assert!(Equal::isEq(&branch(Box::new(leaf(magenta)), Box::new(leaf(cyan))),
+ &branch(Box::new(leaf(magenta)), Box::new(leaf(cyan)))));
+
+ assert!(!Equal::isEq(&branch(Box::new(leaf(magenta)), Box::new(leaf(cyan))),
+ &branch(Box::new(leaf(magenta)), Box::new(leaf(magenta)))));
+
+ println!("Assertions all succeeded!");
+}