EvWatcher::clear

If the watcher is pending, this method clears its pending status and returns its revents bitset(as if its callback was invoked). If the watcher isn't pending it does nothing and returns 0 .

Sometimes it can be useful to "poll" a watcher instead of waiting for its callback to be invoked, which can be accomplished with this function.

In case if the watcher is pending, returns revents bitset as if the watcher callback had been invoked. Otherwise returns 0 .