ViewConfigurable.swift

protocol ViewConfigurable {}

extension ViewConfigurable where Self: UIView {
  
  func configure(_ block: (Self) -> Void) -> Self {
    block(self)
    return self
  }
  
}

extension UIView: ViewConfigurable {}

final View: UIView {
  
  // Assim é mais verboso
  private let label: UILabel = {
    let label = UILabel()
    label.text = "Hello World"
    label.textColor = .red
    return label
  }()
  
  // Com o configure, fica menos verboso.
  private let label = UILabel().configure {
    $0.text = "Hello World"
    $0.textColor = .red
  }

}