I really like the proposal, but I may not fully understand the core idea ;).
What exactly do you mean by:
> In a release build the RC operations can be left out and with a type based
> allocator we still have memory safety!
Does this refer to memory safety as in "no memory leaks" or as in "no memory
corruption"? I always thought it is the latter.
What would happen for instance in this example:
var n: owned Node = fromSomewhere()
let dangling = unowned(n)
if random() > 1e5:
# imagine lots of code here
dangling = nil
else:
# imagine lots of code here
# but programmer forgets to remove the unowned ref
# reassignment => free old owned Node
n = Node(data: 4)
if not dangling.isNil():
echo dangling.data
Run
In a debug build, the reassignment would lead to an abort if we ever execute
the unlikely branch that forgets to remove the ref. But in a release build the
last line would read corrupted memory, wouldn't it? Just because it points to
memory of the right type, it doesn't mean that it is not an issue?
