No.
It all depends on your airline, but usually they allow 1 Piece of Handluggage + 1 "Personal Item" aka. Laptop Bag, Briefcase, Bagpack or SLR Bagpack.
I could imagine that most of the time you would get away with it - but that doesn't change the fact that the Rules don't allow it. The crew can force you to gatecheck one piece of your Handluggage.