Where in memory or which mechanism manages the reference that does not increase the reference count and does not cause object retention?

In iOS, when using Automatic Reference Counting (ARC), there is a concept of weak references. A weak reference is a reference to an object that does not increase the retain count and does not keep the object in memory.

Such references are usually implemented using weak pointers, which are stored in a special memory area managed by the ARC system. When the object referenced by a weak reference is deallocated, the weak reference is automatically set to nil to avoid dangling pointers.

Thus, a weak reference does not affect the object's lifecycle and does not retain it in memory. This is useful for preventing retain cycles, for example, between a delegate and its owner.

Example in Swift:

class Person {
    var name: String
    weak var delegate: PersonDelegate?
    init(name: String) {
        self.name = name
    }
}

protocol PersonDelegate: AnyObject {
    func didUpdateName()
}

Here, delegate is a weak reference that does not increase the retain count and does not retain the delegate object.