Do you need weak capture in @escaping closure?

Using Swift
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1

Say you have a closure that uses self, so you pass it to another function where it's defined as @escaping do you still need to use weak/unowned self?

To give an example, imagine you pass a closure:

func doAction(@escaping action: () -> Void)

And let's say that you call that function, providing for the action parameter a closure:

{ // here self is a class/actior
   self.  ...
}

You still need need to use [weak self] inside the closure, right?

2

That entirely depends on the lifetimes and semantics of self and of the @escaping closure, which aren’t given here.

  • If the closure won’t outlive self, and capturing self strongly does not create a circular reference, it doesn’t matter. I’d use a strong capture for convenience.
  • If the closure won’t outlive self, but a strong capture would create a circular reference, use [unowned self].
  • If the closure may outlive all other references to self, and you want the closure to keep self alive, capture self strongly.
  • If the closure may outlive all other references to self, and you don’t want the closure to keep self alive, use [weak self].
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