gistfile1.cs

private readonly ConcurrentBag<Tuple<Func<IUser, object>, Func<IUser, Task>>> GlobalUserListeners = new ConcurrentBag<Tuple<Func<IUser, object>, Func<IUser, Task>>>();
        private readonly ConcurrentDictionary<int, IList<Tuple<Func<IUser, object>, Func<IUser, Task>, object>>> UserListeners = new ConcurrentDictionary<int, IList<Tuple<Func<IUser, object>, Func<IUser, Task>, object>>>();
        private readonly ConcurrentBag<Tuple<Func<IChannel, object>, Func<IChannel, Task>>> GlobalChannelListeners = new ConcurrentBag<Tuple<Func<IChannel, object>, Func<IChannel, Task>>>();
        private readonly ConcurrentDictionary<int, IList<Tuple<Func<IChannel, object>, Func<IChannel, Task>, object>>> ChannelListeners = new ConcurrentDictionary<int, IList<Tuple<Func<IChannel, object>, Func<IChannel, Task>, object>>>();


        public void AddListener<T>(Func<T, object> mapper, Func<T, Task> listener) {
            ConcurrentBag<Tuple<Func<T, object>, Func<T, Task>>> globalListeners;
            ConcurrentDictionary<int, IList<Tuple<Func<T, object>, Func<T, Task>, object>>> listeners;
            Type t = typeof(T);

            if (t == typeof(IUser)) {
                object o = GlobalUserListeners;
                globalListeners = (ConcurrentBag<Tuple<Func<T, object>, Func<T, Task>>>)o;
                listeners = UserListeners;
            } else if (t == typeof(IChannel)) {
                globalListeners = GlobalChannelListeners;
                listeners = ChannelListeners;
            } else {
                throw new TypeAccessException();
            }
        }

        private void convertBag<T1, T2>(ConcurrentBag<Tuple<Func<T1, object>, Func<T1, Task>>> bag)
        {
            var ret = new ConcurrentBag<Tuple<Func<T2, object>, Func<T2, Task>>>();
            foreach (var t in bag) {
                Func<T2, object> f1 = (Func<T2, object>)t.Item1;
            }
        }