SwipeReturnable.swift

import UIKit

protocol SwipeReturnable {
    func addSwipeReturnGesture()
}

extension SwipeReturnable where Self: UIViewController {
    func addSwipeReturnGesture() {
        let gestureToRight = UISwipeGestureRecognizer(target: self, action: #selector(self.swipeBack))
        gestureToRight.direction = .Right
        self.view.addGestureRecognizer(gestureToRight)
    }
}

extension UIViewController {
     @objc private func swipeBack() {
        self.navigationController?.popViewControllerAnimated(true)
    }
}