+ EV_CB_DECLARE(type)
+ EV_CB_INVOKE(watcher,revents)
+ ev_set_cb(ev,cb)
+
+ Can be used to change the callback member declaration in each
+ watcher, and the way callbacks are invoked and set. Must expand
+ to a struct member definition and a statement, respectively. See
+ the ev.v header file for their default definitions. One possible
+ use for overriding these is to avoid the ev_loop pointer as first
+ argument in all cases, or to use method calls instead of plain
+ function calls in C++.
+