Going by personal experiences, I would suggest not to ask as some people will take it in an offencive way.
On top of this, sometimes it's better living with the thought they could be AS; It gives you that good feeling thinking that there just may be someone in your class like you. Personally I believe it's better to continue life with this remaining a mystery and enjoy the feeling of knowing that particular person just may be AS, rather then risk offending them by asking such a question.