Joe Groff

@chriseidhof Yeah, so we can check whether the object is still alive before strong-retaining it again.

@jckarter wait, so as long as there's an unowned ref, memory isn't freed? How does unowned prevent ref cycles then?

@jckarter when A refers B strongly, and B refers A unowned, it still creates a cycle? Because A only is released after unowned releases?

@chriseidhof The object is destroyed and gives up all its resources when the last strong reference is released.

@chriseidhof The memory for the instance is still allocated but left in a zombie state.

@jckarter @chriseidhof just to clarify: does `unowned` behave basically like `assign` in objc?

@heathborders @chriseidhof The property doesn't keep the object alive, but the runtime still validates access to the dead object.

@jckarter @chriseidhof so if the object is dead when you access it, swift guarantees a crash whereas objc doesn't?