ilyapuchka

protocol ProtocolA {}
protocol ProtocolB: ProtocolA {}
protocol ProtocolC {
    func act()
}

protocol ProtocolD {
    typealias V
    func act()
}

ilyapuchka

func z_map<S : SequenceType, T>(source: S, transform: (S.Generator.Element) -> T?) -> [T] {
    // easy, right? =)
    return reduce(source, []) { r, i in map( transform(i) ) { r + [$0] } ?? r }
}

ilyapuchka

import UIKit

struct MainScene {
    let vc: UIViewController
    let nc: UINavigationController
    init(vc: UIViewController) {
        self.vc = vc
        self.nc = UINavigationController(rootViewController: vc)
    }
}

ilyapuchka

protocol HasTitle {
    var ht_title: String {get set}
}

extension UIBarButtonItem: HasTitle {
    var ht_title: String {
        get {
            return self.title ?? ""
        }
        set {