Yep, AutoCAD has had it for a while. When it showed up in Altium I found it kind of annoying at first, but it's sort of helpful after getting used to it. Still lots of times you just have to use E,S,I or E,S,O to specifically select inside/outside though just with PCBs being what they are. There are probably ways to make selection in the PCB editor a lot better, but I don't trust Altium to figure that out.