// Demonstrate single and multiple trailing closures.

// 1. Using the built-in UIView.animate()
// (same example used on SE-0279)

let view = UIView()
// Single trailing closure argument (works)
UIView.animate(withDuration: 0.3) {
  view.alpha = 0
}
// Multiple trailing closure arguments (works)
UIView.animate(withDuration: 0.3) {
  view.alpha = 0
} completion: { _ in
  view.removeFromSuperview()
}

// 2. Using a faked animate() with the same method signature
// as UIView.animate().

func animate(withDuration duration: TimeInterval, animations: @escaping () -> Void, completion: ((Bool) -> Void)? = nil) {
    
}

// Single trailing closure argument (does not work)
animate(withDuration:1.0) { // << ERROR
    view.alpha = 0.0
}
// Multiple trailing closure arguments (works)
animate(withDuration:1.0) {
    
} completion: { _ in
    
}