improved `cellForIndexPath` for UICollectionView and UITableView

TableViewHeaderProtocol.swift

protocol TableViewHeaderProtocol: ViewCellReuseIdentifier {
    init()
    
    func setupLayout()
}

extension TableViewHeaderProtocol where Self: UITableViewHeaderFooterView {
    
    init() {
        self.init(reuseIdentifier: Self.reuseIdentifier)
    }
}

UICollectionView.swift

extension UICollectionView {
    
    func cellForIndexPath<T: ViewCellProtocol>(indexPath: NSIndexPath) -> T {
        guard let cell = self.dequeueReusableCellWithReuseIdentifier(T.reuseIdentifier, forIndexPath: indexPath) as? T else {
            assertionFailure("Did you forgot to register cell with identifier `\(T.reuseIdentifier)` for type: `\(T.self)`")
            return T()
        }
        
        return cell
    }
}

UITableView.swift

extension UITableView {
    
    func cellForIndexPath<T: ViewCellProtocol>(indexPath: NSIndexPath) -> T {
        guard let cell = self.dequeueReusableCellWithIdentifier(T.reuseIdentifier, forIndexPath: indexPath) as? T else {
            assertionFailure("Did you forgot to register cell with identifier `\(T.reuseIdentifier)` for type: `\(T.self)`")
            return T()
        }
        
        return cell
    }
    
    func headerView<T: BaseTableViewHeaderProtocol>() -> T {
        guard let view = self.dequeueReusableHeaderFooterViewWithIdentifier(T.reuseIdentifier) as? T else {
            assertionFailure("Did you forgot to register view with identifier `\(T.reuseIdentifier)` for type: `\(T.self)`")
            return T()
        }
        
        return view
    }
}

ViewCellProtocol.swift

protocol ViewCellProtocol: ViewCellReuseIdentifier {
    init()
    
    func setupLayout()
}

extension ViewCellProtocol where Self: UIView {
    
    init() {
        self.init(frame: CGRectZero)
    }
}

ViewCellReuseIdentifier.swift

protocol ViewCellReuseIdentifier {
    static var reuseIdentifier: String { get }
}

extension ViewCellReuseIdentifier where Self: UIView {
    static var reuseIdentifier: String {
        return "\(self)"
    }
}