Maybe a few other points to your video: You say that references are useful when data are shared, you gave an example for the case where two objects both have a ref to another object. That is fine, but for beginners a larger, real world example would be nice. I think when I was a kid data sharing would have made not much sense for me without a more detailed use case.
The other point is, that you said that for references we do not need the var keyword when passing data to procs -- we can modify the fields of object passed as references always. Well, beginners may be confused: Is the most significant advantage of references that we don't have to type that var keyword in the proc signature? So why not always us references as done in Java and Python, so that we never would have to use a var parameter. And related question: When we have a ref parameter, how can we avoid that fields can be modified? Then you were talking about scopes and locality. That was a bit off topic, but I know why you did. Next point: You assigned nil to a ref and show that accessing thet values would give a runtime error then. OK, but if I remember correctly you say then that it is because the GC has freed the object. That is not really correct, as the default refc GC may free objects with delay. When you assign nil to a ref, then trying to access the old value would fail, but the object may be still somewhere in memory, until GC really frees it. And finally for ORC: First that does not really belong into this video, maybe make a own video for ARC, ORC, move semantic, cursor annotation and all that? And, when you want to advertize Nim, it is always a good idea to call ARC not a GarbageCollector, but call it Rust like deterministic memory management. Some people really like that term better than GC. Yes I know ORC is in between, that is why I generally talk about ARC only, most software should work with ARC fine.
