Merge pull request #132 from aepsil0n/approx_eq_macros

Assertion macros for approximate equality

src/approx.rs

@@ -42,3 +42,29 @@ macro_rules! approx_float(
 
 approx_float!(f32)
 approx_float!(f64)
+
+#[macro_export]
+macro_rules! assert_approx_eq_eps(
+    ($given: expr, $expected: expr, $eps: expr) => ({
+        let eps = &($eps);
+        let (given_val, expected_val) = (&($given), &($expected));
+        if !given_val.approx_eq_eps(expected_val, eps) {
+            fail!("assertion failed: `left ≈ right` (left: `{}`, right: `{}`, tolerance: `{}`)",
+                *given_val, *expected_val, *eps
+            )
+        }
+    })
+)
+
+#[macro_export]
+macro_rules! assert_approx_eq(
+    ($given: expr, $expected: expr) => ({
+        let (given_val, expected_val) = (&($given), &($expected));
+        if !given_val.approx_eq(expected_val) {
+            fail!("assertion failed: `left ≈ right` (left: `{}`, right: `{}`, tolerance: `{}`)",
+                *given_val, *expected_val,
+                ApproxEq::approx_epsilon(Some(*given_val))
+            )
+        }
+    })
+)

tests/approx.rs

@@ -0,0 +1,44 @@
+// Copyright 2014 The CGMath Developers. For a full listing of the authors,
+// refer to the AUTHORS file at the top-level directory of this distribution.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#![feature(globs)]
+#![feature(phase)]
+
+#[phase(plugin, link)]
+extern crate cgmath;
+
+use cgmath::*;
+
+#[test]
+fn macro_assert_approx_eq_eps() {
+    assert_approx_eq_eps!(1.0f64, 1.001, 0.01);
+}
+
+#[test]
+#[should_fail]
+fn macro_assert_approx_eq_eps_fail() {
+    assert_approx_eq_eps!(1.0f32, 1.02, 0.01);
+}
+
+#[test]
+fn macro_assert_approx_eq() {
+    assert_approx_eq!(7.0f32 / 5.0, 1.4);
+}
+
+#[test]
+#[should_fail]
+fn macro_assert_approx_eq_fail() {
+    assert_approx_eq!(1.0f64 / 3.0, 0.333);
+}