-- category "ignored" should be dropped, since it's not portable (what's its
- size on remote site?). But function's pointer may benefit from it.
- We could change it to an attribute just as the "cycle" one. That way, it
- would get malloced, but not transfered.
+- when a send failed because the socket was closed on the other side,
+ try to reopen it seamlessly. Needs exceptions or another way to
+ differentiate between the several system_error.
+- cache accepted sockets and close the old ones after a while.
+ Depends on the previous item.
+