ARC is one of the oldest (if not the oldest) kinds of GC out there. It&#x27;s even the subject of one of the famous AI Koans:<p><a href="http:&#x2F;&#x2F;www.catb.org&#x2F;jargon&#x2F;html&#x2F;koans.html" rel="nofollow">http:&#x2F;&#x2F;www.catb.org&#x2F;jargon&#x2F;html&#x2F;koans.html</a> (see &quot;Moon instructs a student&quot;)<p>It stopped being considered proper garbage collection long ago because of the inability to collect circular references without help, which of course is the subject of that story. Apple is doing decently well with their version of it, but they&#x27;re essentially reinventing ancient history.<p>Other GCs often have weak pointers too. You just use them less, because with a GC that can deal with circular references you don&#x27;t need them nearly as often.