feat: optionally integrate with num-cmp

Signed-off-by: tison <wander4096@gmail.com>

Cargo.toml

@@ -25,6 +25,7 @@ proptest   = { version = "1.0.0", optional = true }
 speedy     = { version = "0.8.3", optional = true, default-features = false }
 bytemuck   = { version = "1.12.2", optional = true, default-features = false }
 borsh      = { version = "1.2.0", optional = true, default-features = false }
+num-cmp    = { version = "0.1.0", optional = true }
 
 [dev-dependencies]
 serde_test = "1.0"

src/lib.rs

@@ -79,6 +79,66 @@ fn canonicalize_signed_zero<T: FloatCore>(x: T) -> T {
 #[repr(transparent)]
 pub struct OrderedFloat<T>(pub T);
 
+#[cfg(feature = "num-cmp")]
+mod impl_num_cmp {
+    use super::OrderedFloat;
+    use core::cmp::Ordering;
+    use num_cmp::NumCmp;
+    use num_traits::float::FloatCore;
+
+    impl<T, U> NumCmp<U> for OrderedFloat<T>
+    where
+        T: FloatCore + NumCmp<U>,
+        U: Copy,
+    {
+        fn num_cmp(self, other: U) -> Option<Ordering> {
+            NumCmp::num_cmp(self.0, other)
+        }
+
+        fn num_eq(self, other: U) -> bool {
+            NumCmp::num_eq(self.0, other)
+        }
+
+        fn num_ne(self, other: U) -> bool {
+            NumCmp::num_ne(self.0, other)
+        }
+
+        fn num_lt(self, other: U) -> bool {
+            NumCmp::num_lt(self.0, other)
+        }
+
+        fn num_gt(self, other: U) -> bool {
+            NumCmp::num_gt(self.0, other)
+        }
+
+        fn num_le(self, other: U) -> bool {
+            NumCmp::num_le(self.0, other)
+        }
+
+        fn num_ge(self, other: U) -> bool {
+            NumCmp::num_ge(self.0, other)
+        }
+    }
+
+    #[test]
+    pub fn test_num_cmp() {
+        let f = OrderedFloat(1.0);
+
+        assert_eq!(NumCmp::num_cmp(f, 1.0), Some(Ordering::Equal));
+        assert_eq!(NumCmp::num_cmp(f, -1.0), Some(Ordering::Greater));
+        assert_eq!(NumCmp::num_cmp(f, 2.0), Some(Ordering::Less));
+
+        assert!(NumCmp::num_eq(f, 1));
+        assert!(NumCmp::num_ne(f, -1));
+        assert!(NumCmp::num_lt(f, 100));
+        assert!(NumCmp::num_gt(f, 0));
+        assert!(NumCmp::num_le(f, 1));
+        assert!(NumCmp::num_le(f, 2));
+        assert!(NumCmp::num_ge(f, 1));
+        assert!(NumCmp::num_ge(f, -1));
+    }
+}
+
 impl<T: FloatCore> OrderedFloat<T> {
     /// Get the value out.
     #[inline]