Why specify [unowned self] in blocks where you depend on self being there?

Question

I want self to be non-nil and I\'m sure it will be, during the blocks execution. So why explicitly specify [unowned self] ?

object.executeBlock {
    date =         


        

Answer 1

I answered this elsewhere. Here's the Cliff notes:

If self could be nil in the closure use [weak self].

If self will never be nil in the closure use [unowned self].

If it's crashing when you use [unowned self] I would guess that self is nil at some point in that closure, which is why you had to go with [weak self] instead.

I really liked the whole section from the manual on using strong, weak, and unowned in closures:

https://developer.apple.com/library/ios/documentation/swift/conceptual/swift_programming_language/AutomaticReferenceCounting.html