class SignUpVC: UIViewController {
    @IBOutlet weak var signUpButton: UIButton!

    var completionBlock: (() -> Void)?

    override func viewDidLoad() {
        super.viewDidLoad()
        signUpButton.fs_addCornerRadius(10)
    }

    @IBAction func dismissButton(_ sender: UIButton) {
        goAway()
    }

    private func goAway() {
        completionBlock!()
    }

    class func present(from pFrom: UIViewController, completion pCompletion: @escaping () -> Void) {
        let theStoryboard = UIStoryboard.init(name: "SignUp", bundle: nil)
        let signUpVC = theStoryboard.instantiateViewController(withIdentifier: "SignUpVC") as! SignUpVC
        signUpVC.completionBlock = pCompletion
        signUpVC.modalPresentationStyle = .overCurrentContext
        pFrom.present(signUpVC, animated: true)
    }
}

class SomeVC: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
         SignUpVC.present(from: self) {
            self.dismiss(animated: true)
        }
    }
}