Callback function for change streams in mongocxx

I am using mongocxx 3.6.2 driver together with replica set. Recently, I have been exploring about change streams which are helpful to get notified data changes. After looking the mongocxx examples on change streams and documentation I didn’t understand how to get notified on changes forever.

in node.js driver, there is callback function like event which you can receive whenever data is updated and process the data. But in c++ driver there isn’t anything like that.

Am I missing something? Any help would be appreciated.