Add `deserializer()` in `serializer.tmpl` to have a single function that generates all the necessary functions into the template specialization like `serializer()`. This also avoids the duplication of some conditional logic. Signed-off-by: Barnabás Pőcze <barnabas.pocze@ideasonboard.com> Reviewed-by: Paul Elder <paul.elder@ideasonboard.com> Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>