test.swift

struct Section<CellType: UICollectionViewCell, ModelType: AnyObject> {
    var numberOfItems: Int { return elements.count }
    var elements: [ModelType]
    var identifier: String { return String(describing: type(of: ModelType.self)) }
    var configurator: CollectionCellConfigurator<CellType, ModelType>
}


protocol Configurator {
    var configureCell: (UICollectionViewCell, AnyObject) -> () { get set }
}

struct CollectionCellConfigurator<Cell: UICollectionViewCell, Item: AnyObject>: Configurator {
    let configureCell: (Cell, Item) -> ()
}