Debounce function for Swift 3

Debounce.swift

func debounce(_ action: @escaping () -> Void) {
  let lastFireTime = DispatchTime.now()
  let dispatchDelay = TimeInterval(0.3)
  
  DispatchQueue.main.asyncAfter(deadline: .now() + dispatchDelay) {
    let now = DispatchTime.now()
    let when = lastFireTime + dispatchDelay
    if now >= when {
      action()
    }
  }
}

This looks like a complicated delay, not a debounce.

This looks like a complicated delay, not a debounce.

Why complicated? Looks basic to me