[chris6f]

It's probably better to let the user/application decide what to do in these cases, and for this reason we allow them to register type-specific (de)serialization routines.

In the case of network connections, the user could instead serialize connection details and then recreate the connection when deserializing the coroutine state. Same thing for files, where instead of serializing unstable low-level details like the file descriptor, the user can instead serialize higher level information (path, open flags, etc) and recreate the open file when deserializing the coroutine state.