Different structs in one array in Swift

I have a struct called trip.

struct trip {
    var name: String
    var description: String
    var elements: [Any] = []

    mutating func addItemToElements(newValue: Any) {
       elements.append(newValue)
    }
}

As you can see, there is an array inside. I'm adding some other structs like element_flight into this array by function addItemtoElements.

struct element_flight {
    var origin: String
    var destination: String
    var flightno: String
    var departure: NSDate
    var arrival: NSDate
    var seat: String
}

Then I'm trying to create a list using table view:

    override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCell(withIdentifier: "elementTrip", for: indexPath) as! CellInElementsOfTripsTableViewCell
    let elem = trips[0].elements[indexPath.row]
    cell.mainTextLabel.text = elem.origin //it doesn't work

    retu cell
}

I can't get any of parts of struct (like origin in code). What am I doing wrong?

I'm creating similar structs to element_flight and it could be the best way to put it in one array and then show in table view.