Memory Safety without a GC or Ref Counting

[F i L]

F i L wrote:
> ... Also, I can't remember exactly, but because var's are tied 
> to scopes, I think there's more optimization that can happen 
> with ref-counting because it happens at the scope level... more 
> thoughts needed here though.

Ah right I remember. Since vars only ever get collected at the 
end of a scope, you don't need to check for zero-refs on every 
dereference, only at the end of the var's scope.