Add missing Option impl for CastRaw and TryCastRaw

src/cast.rs

@@ -621,6 +621,16 @@ where
   }
 }
 
+unsafe impl<T, U> CastRaw<Option<U>> for Option<T>
+where
+  T: CastRaw<U>,
+  U: Copy,
+{
+  fn cast_raw(self) -> Option<U> {
+    self.map(|x| x.cast_raw())
+  }
+}
+
 #[cfg(feature = "extern_crate_alloc")]
 unsafe impl<T, U> CastRaw<RawCow<*const U, U>> for RawCow<*const T, T>
 where
@@ -811,6 +821,19 @@ where
   }
 }
 
+unsafe impl<T, U> TryCastRaw<Option<U>> for Option<T>
+where
+  T: TryCastRaw<U>,
+  U: Copy,
+{
+  fn try_cast_raw(self) -> Result<Option<U>, PodCastError> {
+    match self {
+      Some(x) => Ok(Some(x.try_cast_raw()?)),
+      None => Ok(None),
+    }
+  }
+}
+
 #[cfg(feature = "extern_crate_alloc")]
 unsafe impl<T, U> TryCastRaw<RawCow<*const U, U>> for RawCow<*const T, T>
 where