proc addSubscriber*[T](d: var Data[T], cb: proc(d:T)) = d.subscribers.add(cb) Run
A typo `T` for `Data[T]`, and `var` needed for `add`.
proc addSubscriber*[T](d: var Data[T], cb: proc(d:T)) = d.subscribers.add(cb) Run
A typo `T` for `Data[T]`, and `var` needed for `add`.