1 files changed, 42 insertions, 0 deletions
diff --git a/third_party/rust/euclid/src/approxeq.rs b/third_party/rust/euclid/src/approxeq.rs
new file mode 100644
index 0000000000..911f5268a4
--- /dev/null
+++ b/third_party/rust/euclid/src/approxeq.rs
@@ -0,0 +1,42 @@
+// Copyright 2013 The Servo Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+/// Trait for testing approximate equality
+pub trait ApproxEq<Eps> {
+    /// Default epsilon value
+    fn approx_epsilon() -> Eps;
+
+    /// Returns `true` is this object is approximately equal to the other one, using
+    /// a provided epsilon value.
+    fn approx_eq_eps(&self, other: &Self, approx_epsilon: &Eps) -> bool;
+
+    /// Returns `true` is this object is approximately equal to the other one, using
+    /// the `approx_epsilon()` epsilon value.
+    fn approx_eq(&self, other: &Self) -> bool {
+        self.approx_eq_eps(other, &Self::approx_epsilon())
+    }
+}
+
+macro_rules! approx_eq {
+    ($ty:ty, $eps:expr) => {
+        impl ApproxEq<$ty> for $ty {
+            #[inline]
+            fn approx_epsilon() -> $ty {
+                $eps
+            }
+            #[inline]
+            fn approx_eq_eps(&self, other: &$ty, approx_epsilon: &$ty) -> bool {
+                num_traits::Float::abs(*self - *other) < *approx_epsilon
+            }
+        }
+    };
+}
+
+approx_eq!(f32, 1.0e-6);
+approx_eq!(f64, 1.0e-6);