And regarding to your worry about the performance ...
# opensource
v
And regarding to your worry about the performance of opening and closing a Realm instance for each operation, I have measured that on a Samsung Galaxy S4, and it takes me between 8 - 14 ms both operations in total, which I think is quite acceptable. However, I'm going to add managed versions of query methods, like queryManaged(realm : Realm, query: (RealmQuery<T>) -> Unit), in order to be able to use your own realm instance, in case someone prefer that way.