tutoreact: Forum_notif.notify doesn't take a function as argument but a Forum_notif.server_notif

[adrien-n]

The compiler complains about the second argument to notify in the following line:

Forum_notif.notify forumid (fun userid -> Lwt.return (Some id));

The message is:

This expression should not be a function, the expected type is Forum_notif.server_notif

I'm not sure what the fix should be.