Find the indexPath of a button inside UITableViewCell when button pressed?

The code below correctly returns the cell:

func findSuperView(sender:UIButton!) -> UITableViewCell { 
    var superView : UIView? = sender.superview 
    var foundSuperView : UITableViewCell! 

    while superView != nil && foundSuperView == nil { 
        if let cell = superView as? UITableViewCell { 
            foundSuperView = cell 
            break 
        } 
        else { 
            superView = superView?.superview 
        } 
    } 
    return foundSuperView 
}

But for finding indexpath in tableview it crashes:

var indexPath : NSIndexPath = self.table .indexPathForCell(findSuperView(sender))!
println("Section (indexPath)")

And I tried another way, but it was not successful:

var button : UIButton = sender as UIButton; 
var touch: UITouch = events .allTouches()?.anyObject() as UITouch 
var location : CGPoint = touch.locationInView(self.table) 
var indexPath : NSIndexPath = self.table.indexPathForRowAtPoint(location)!