std: Flesh out result::extensions.

Author: erickt

Diff for: src/libcore/result.rs

@@ -109,6 +109,14 @@ fn chain_err<T: copy, U: copy, V: copy>(
 }
 
 impl extensions<T:copy, E:copy> for result<T,E> {
+    fn get() -> T { get(self) }
+
+    fn get_err() -> E { get_err(self) }
+
+    fn success() -> bool { success(self) }
+
+    fn failure() -> bool { failure(self) }
+
     fn chain<U:copy>(op: fn(T) -> result<U,E>) -> result<U,E> {
         chain(self, op)
     }