Make event loop implementations final

source/tanya/async/event/epoll.d

@@ -34,7 +34,7 @@ extern (C) nothrow @nogc
 	int epoll_wait (int epfd, epoll_event *events, int maxevents, int timeout);
 }
 
-class EpollLoop : SelectorLoop
+final class EpollLoop : SelectorLoop
 {
 	protected int fd;
 	private Vector!epoll_event events;

source/tanya/async/event/iocp.d

@@ -26,7 +26,7 @@ import core.sys.windows.winbase;
 import core.sys.windows.windef;
 import core.sys.windows.winsock2;
 
-class IOCPStreamTransport : StreamTransport
+final class IOCPStreamTransport : StreamTransport
 {
 	private WriteBuffer!ubyte input;
 
@@ -106,7 +106,7 @@ class IOCPStreamTransport : StreamTransport
 	}
 }
 
-class IOCPLoop : Loop
+final class IOCPLoop : Loop
 {
 	protected HANDLE completionPort;
 

source/tanya/async/event/kqueue.d

@@ -113,7 +113,7 @@ extern(C) int kevent(int kq, const kevent_t *changelist, int nchanges,
                      kevent_t *eventlist, int nevents, const timespec *timeout)
                      nothrow @nogc;
 
-class KqueueLoop : SelectorLoop
+final class KqueueLoop : SelectorLoop
 {
 	protected int fd;
 	private Vector!kevent_t events;

source/tanya/async/event/selector.d

@@ -25,7 +25,7 @@ import tanya.network.socket;
 /**
  * Transport for stream sockets.
  */
-class SelectorStreamTransport : IOWatcher, StreamTransport
+final class SelectorStreamTransport : IOWatcher, StreamTransport
 {
 	/// Input buffer.
 	package WriteBuffer!ubyte input;