Swift Issue

@IBOutlet var customerDashboardButtons:[NSArray]?

var predicate = NSPredicate(format: "SELF.tag == %d", tag)
var filteredButtons = customerDashboardButtons!.filter { predicate.evaluateWithObject($0) };
if 0 < filteredButtons.count {
      var button = customerDashboardButtons!.first
      button.hidden = true // getting an error in this line as "Type of expression is ambiguous without more context
 }