Swift Singleton

Singleton.swift

#if canImport(Darwin)
import Darwin
#else
import Glibc
#endif

class Singleton {
    static var shared: Singleton! = Singleton()

    private init() {
        print("init")

        atexit {
            Singleton.shared = nil
        }
    }

    deinit {
        print("deinit")
    }

    func test() {
        print("test")
    }
}

Singleton.shared.test()

stdout.txt

init
test
deinit