1 files changed, 77 insertions, 0 deletions
diff --git a/third_party/rust/float-cmp/src/macros.rs b/third_party/rust/float-cmp/src/macros.rs
new file mode 100644
index 0000000000..7eeaa30fd9
--- /dev/null
+++ b/third_party/rust/float-cmp/src/macros.rs
@@ -0,0 +1,77 @@
+
+#[macro_export]
+macro_rules! approx_eq {
+    ($typ:ty, $lhs:expr, $rhs:expr) => {
+        {
+            let m: <$typ as $crate::ApproxEq>::Margin = Default::default();
+            <$typ as $crate::ApproxEq>::approx_eq($lhs, $rhs, m)
+        }
+    };
+    ($typ:ty, $lhs:expr, $rhs:expr $(, $set:ident = $val:expr)*) => {
+        {
+            let m = <$typ as $crate::ApproxEq>::Margin::zero()$(.$set($val))*;
+            <$typ as $crate::ApproxEq>::approx_eq($lhs, $rhs, m)
+        }
+    };
+    ($typ:ty, $lhs:expr, $rhs:expr, $marg:expr) => {
+        {
+            <$typ as $crate::ApproxEq>::approx_eq($lhs, $rhs, $marg)
+        }
+    };
+}
+
+// Until saturating_abs() comes out of nightly, we have to code it ourselves.
+macro_rules! saturating_abs_i32 {
+    ($val:expr) => {
+        if $val.is_negative() {
+            match $val.checked_neg() {
+                Some(v) => v,
+                None => std::i32::MAX
+            }
+        } else {
+            $val
+        }
+    };
+}
+macro_rules! saturating_abs_i64 {
+    ($val:expr) => {
+        if $val.is_negative() {
+            match $val.checked_neg() {
+                Some(v) => v,
+                None => std::i64::MAX
+            }
+        } else {
+            $val
+        }
+    };
+}
+
+#[test]
+fn test_macro() {
+    let a: f32 = 0.15 + 0.15 + 0.15;
+    let b: f32 = 0.1 + 0.1 + 0.25;
+    assert!( approx_eq!(f32, a, b) ); // uses the default
+    assert!( approx_eq!(f32, a, b, ulps = 2) );
+    assert!( approx_eq!(f32, a, b, epsilon = 0.00000003) );
+    assert!( approx_eq!(f32, a, b, epsilon = 0.00000003, ulps = 2) );
+    assert!( approx_eq!(f32, a, b, (0.0, 2)) );
+}
+
+#[test]
+fn test_macro_2() {
+    assert!( approx_eq!(f64, 1000000_f64, 1000000.0000000003_f64) );
+    assert!( approx_eq!(f64, 1000000_f64, 1000000.0000000003_f64, ulps=3) );
+    assert!( approx_eq!(f64, 1000000_f64, 1000000.0000000003_f64, epsilon=0.0000000004) );
+    assert!( approx_eq!(f64, 1000000_f64, 1000000.0000000003_f64, (0.0000000004, 0)) );
+    assert!( approx_eq!(f64, 1000000_f64, 1000000.0000000003_f64, (0.0, 3)) );
+}
+
+#[test]
+fn test_macro_3() {
+    use crate::F32Margin;
+
+    let a: f32 = 0.15 + 0.15 + 0.15;
+    let b: f32 = 0.1 + 0.1 + 0.25;
+    assert!( approx_eq!(f32, a, b, F32Margin { epsilon: 0.0, ulps: 2 }) );
+    assert!( approx_eq!(f32, a, b, F32Margin::default()) );
+}