Fairly unlikely.

That said, try to sleep somewhere that is both not immediately visible to passers-by but also never sleep anywhere with only one exit that an attacker could block you in. I've had stuff stolen while I slept next to it, even touching it, but if they can take it without waking you up, they will.

Random violence is rare but even so if you're not sleeping in an "obvious" place (e.g. park bench, doorway, all of which are ~a jillion per cent more likely to be harassed by the pigs anyway) I think you wouldn't present an appealing target to the sorts of boys who go out looking to do violence to the homeless.