Tap.swift

class Tap {
  private static var instances: [Tap] = []
  
  // ...  

  static func on(view: UIView, fires action: @escaping () -> Void) {
    let tap = Tap(view: view, action: action)
    Tap.instances.append(tap)
  }
  
  private init(view: UIView, action: @escaping () -> Void) { /* ... */ }
    
  // ...
  
}