Use core::f32 instead of std::f32

src/lib.rs

@@ -418,8 +418,8 @@ fn clamp_test() {
     assert_eq!(-1.0, clamp_lower(-2.0, -1.0));
     assert_eq!(-1.0, clamp_upper(1.0, -1.0));
     assert_eq!(-2.0, clamp_upper(-2.0, -1.0));
-    assert!(clamp_lower(std::f32::NAN, 1.0).is_nan());
-    assert!(clamp_upper(std::f32::NAN, 1.0).is_nan());
+    assert!(clamp_lower(::core::f32::NAN, 1.0).is_nan());
+    assert!(clamp_upper(::core::f32::NAN, 1.0).is_nan());
 }
 
 #[test]