ARC 工作方法和强、弱和 UnOwned 引用的必要性

Question

I was facing problem with deallocation of View Controller in my code, then I read about how ARC work and about Strong, Weak and UnOwned references. I was wondering, why swift has made it so complicated? deallocation problem could be solved using slightly different method than what ARC method does. Here is my method:

We can think dependency between objects as directed graph, and can find an unReachable part of graph from current location using proper(using flags) BFS search(in O(n)), and then we can de-initialise all instances which are in unreachable part of graph. Then we can directly work with strong references and there will be no need for weak or unowned references.

Am I missing something here? May be some performance issue or some limitations. Can someone please give me a reason for necessity of Strong, Weak and UnOwned references or some article/document which can explain reason for above in detail?

Answer 1

This is the official documentation and this is a more entertaining discussion . For the most part ARC stays out of your way, just requiring some hints eg when creating closures that reference self but execute in the context of another component.