Mastering Swift 3

Creating strong reference cycles with closures

Earlier in this chapter, we said the best thing is that, for the most part, Swift will handle memory management for us. The for the most part section of the quote means that if everything is written in a standard way, Swift will handle the memory management of the closures for us. However, there are times where memory management fails us. Memory management will work correctly for all of the examples that we have seen in this chapter so far. It is possible to create a strong reference cycle that would prevent Swift's memory management from working correctly. Let's look at what happens if we create a strong reference cycle with closures.

A strong reference cycle may happen if we assign a closure to a ...