1 files changed, 7 insertions, 0 deletions
diff --git a/src/libcore/cmp.rs b/src/libcore/cmp.rs
index b933b60a39f..80f1f05961a 100644
--- a/src/libcore/cmp.rs
+++ b/src/libcore/cmp.rs
@@ -66,6 +66,13 @@ totaleq_impl!(uint)
 
 totaleq_impl!(char)
 
+/// Trait for testing approximate equality
+pub trait ApproxEq<Eps> {
+    fn approx_epsilon() -> Eps;
+    fn approx_eq(&self, other: &Self) -> bool;
+    fn approx_eq_eps(&self, other: &Self, approx_epsilon: &Eps) -> bool;
+}
+
 #[deriving(Clone, Eq)]
 pub enum Ordering { Less = -1, Equal = 0, Greater = 1 }