NSHashTable++Example++1.swift

final class Test {
    deinit {
        print("Deinited")
    }
}

let hashTable: NSHashTable<Test> = .weakObjects()

var optionalInstance: Test? = Test()

hashTable.add(optionalInstance)

print(hashTable.allObjects.count)

optionalInstance = nil

DispatchQueue.main.asyncAfter(deadline: .now() + 0.5) {
    print(hashTable.allObjects.count)
}