Hmm, I have no idea about the speed comparisons between programming languages, but as far as I know, ability to call for swapping two variables in a single line does not necessarily mean that it is going to be interperetad and executed faster. It's just the way you tell things to compiler/interpreter, and does not give clues about speed I think. Single line of swapping code could take longer or shorter to execute. Speed is not releated to that.
It takes longer to write that code anyways. If that is the issue.