impl ToPrimitive, FromPrimitive and NumCast for Wrapping<T>

traits/src/cast.rs

@@ -1,4 +1,5 @@
 use std::mem::size_of;
+use std::num::Wrapping;
 
 use identities::Zero;
 use bounds::Bounded;
@@ -385,6 +386,17 @@ impl_from_primitive!(u64,   to_u64);
 impl_from_primitive!(f32,   to_f32);
 impl_from_primitive!(f64,   to_f64);
 
+
+impl<T: ToPrimitive> ToPrimitive for Wrapping<T> {
+    fn to_i64(&self) -> Option<i64> { self.0.to_i64() }
+    fn to_u64(&self) -> Option<u64> { self.0.to_u64() }
+}
+impl<T: FromPrimitive> FromPrimitive for Wrapping<T> {
+    fn from_u64(n: u64) -> Option<Self> { T::from_u64(n).map(Wrapping) }
+    fn from_i64(n: i64) -> Option<Self> { T::from_i64(n).map(Wrapping) }
+}
+
+
 /// Cast from one machine scalar to another.
 ///
 /// # Examples
@@ -434,6 +446,11 @@ impl_num_cast!(isize, to_isize);
 impl_num_cast!(f32,   to_f32);
 impl_num_cast!(f64,   to_f64);
 
+impl<T: NumCast> NumCast for Wrapping<T> {
+    fn from<U: ToPrimitive>(n: U) -> Option<Self> {
+        T::from(n).map(Wrapping)
+    }
+}
 
 #[test]
 fn to_primitive_float() {