While @_expose(Cxx) supports enums, it doesn't have the same requirement as @objc and @c for the raw type. The generated representation in the compatibility header for the enums differs too. The attribute @_expose(Cxx) also supports structs, while we consider supporting @c structs in the future, we have yet to pick the best approach so it would likely differ from the C++ one. Although sharing an attribute avoids adding a new one to the language, it also implies a similar behavior between the language interops. However, these behaviors already diverge and we may want to have each feature evolve differently in the future.