deinit.swift

var count: Int = 1234

class C {
    init() {
        myThing = count
        count += 1
        Swift.print("🇺🇸 Entry")
    }

    deinit {
        C.theGlobal = self
        Swift.print("🇺🇸 Exit")
    }

    let myThing: Int
    static var theGlobal: C = C()
}

func main() {
    {
        _ = C()
    }()
    Swift.print(C.theGlobal.myThing)
}

main()

output.txt

🇺🇸 Entry
🇺🇸 Entry
🇺🇸 Exit
🇺🇸 Exit
139638667215401