load(static_cast<T::base_type &>(t));
portable_iarchive.hpp#L412:12: warning: casting 'boost::archive::class_id_type' to 'boost::uint_t<16>::least&' {aka 'short unsigned int&'} does not use 'boost::archive::class_id_type::operator base_type&()' [-Wcast-user-defined]
412 | load((typename boost::uint_t<sizeof(T) * CHAR_BIT>::least&)(t));