Pure protocol factory for Interface Builder-based views(https://blog.hal.codes/ib-constructible)

IBConstructible.swift

protocol IBConstructible: AnyObject {
    static var nibName: String { get }
    static var bundle: Bundle { get }
}

extension IBConstructible {
    static var nibName: String {
        return String(describing: Self.self)
    }

    static var bundle: Bundle {
        return Bundle(for: Self.self)
    }
}

extension IBConstructible where Self: UIViewController {
    static var fromNib: Self {
        let storyboard = UIStoryboard(name: nibName, bundle: bundle)
        guard let viewController = storyboard.instantiateInitialViewController() as? Self else {
            fatalError("Missing view controller in \(nibName).storyboard")
        }
        return viewController
    }
}

extension IBConstructible where Self: UIView {
    static var fromNib: Self {
        let xib = UINib(nibName: nibName, bundle: bundle)
        guard let view = xib.instantiate(withOwner: nil, options: nil).first as? Self else {
            fatalError("Missing view in \(nibName).xib")
        }
        return view
    }
}