Add From<OrderedFloat<f32>> for OrderedFloat<f64> (#183)

Mirrors the existing widening conversion on NotNan so OrderedFloat
has the same API surface. Also adds test coverage for both the new
impl and the previously-untested NotNan widening.

Co-authored-by: Greg Echelberger <gechelberger@gmail.com>

Author: gechelberger

src/lib.rs

@@ -399,6 +399,13 @@ impl_ordered_float_from! {f32, i16}
 impl_ordered_float_from! {f32, u8}
 impl_ordered_float_from! {f32, u16}
 
+impl From<OrderedFloat<f32>> for OrderedFloat<f64> {
+    #[inline]
+    fn from(v: OrderedFloat<f32>) -> OrderedFloat<f64> {
+        OrderedFloat(v.0 as f64)
+    }
+}
+
 impl<T: FloatCore> Deref for OrderedFloat<T> {
     type Target = T;
 

tests/test.rs

@@ -350,6 +350,15 @@ fn not_nan64_bounded() {
     assert_eq!(NotNan::<f64>::max_value(), <f64 as Bounded>::max_value());
 }
 
+#[test]
+fn widen_f32_to_f64() {
+    let of: OrderedFloat<f64> = OrderedFloat(1.5f32).into();
+    assert_eq!(of, OrderedFloat(1.5f64));
+
+    let nn: NotNan<f64> = not_nan(1.5f32).into();
+    assert_eq!(nn, not_nan(1.5f64));
+}
+
 #[test]
 fn not_nan64_from_primitive() {
     assert_eq!(NotNan::<f64>::from_i8(42i8), Some(not_nan(42.0)));