当我编写代码以使用indexOf从数组中查找项目时，它向我显示了上述错误。这是我的代码：-

func addItemViewController(controller: AddItemViewController, didFinishEditingItem item: ChecklistItem)
{
    if let index = items.indexOf(item)
    {
        let indexPath = NSIndexPath(forRow: index, inSection: 0)

        if let cell = tableView.cellForRowAtIndexPath(indexPath)
        {
            configureTextForCell(cell, withChecklistItem: item)
        }
    }