[timsneath]

Ha! But that's not semantically meaningful Swift code in any normal context, nor is it idiomatic. `self` is equivalent to `this` in C++, and is never normally null.

You use this construct for unwrapping nullable fields, for example something like this:

guard let httpResult else { return }

Note that you don't need to assign the value to itself in modern Swift. This line takes an optional (httpResult?) and returns early if null. If not, you can use it with strong guarantees that it's not nullable, so no need for ? or ! to unwrap it later in the scope.

[CBMPET2001]

I've seen that exact pattern used to safely unwrap a weakly captured 'self' within a closure (to avoid retain cycles)

[viktorcode]

> But that's not semantically meaningful Swift code in any normal context, nor is it idiomatic. `self` is equivalent to `this` in C++, and is never normally null.

It is, when `self` is captured weakly in a closure, and that closure is outliving the instance.

[saagarjha]

It’s nil in Swift, and what the other comment said ;)