Charm++

Currently it's not possible to serialize enums in general. However, by using C++11's std::is_enum this can be done by as follows:

template <typename T,
          typename std::enable_if<std::is_enum<T>::value>::type* = nullptr>
inline void operator|(PUP::er& p, T& s) {
  pup_bytes(&p, static_cast<void*>(&s), sizeof(T));
}

This also requires modifying pup.h to

#if __cplusplus >= 201103L
namespace charm_pup_details {

template <typename... Ts>
struct make_void {
  typedef void type;
};
template <typename... Ts>
using void_t = typename make_void<Ts...>::type;

template <typename T, typename U = void>
struct is_pupable : std::false_type{};

template <typename T>
struct is_pupable<
    T, void_t<decltype(std::declval<T>().pup(std::declval<PUP::er &>()))>>
    : std::true_type {};

}  // namespace charm_pup_details
template <class T, typename std::enable_if<charm_pup_details::is_pupable<T>::value, int>::type = 0>
#else
template <class T>
#endif
inline void operator|(PUP::er &p, T &t) {
  p.syncComment(PUP::sync_begin_object);
  t.pup(p);
  p.syncComment(PUP::sync_end_object);
}