On all instances destroyed?

I am making a game like angry birds and I was wondering how I would go about checking to see if all instances of an object have been destroyed? For example the player throws the bird to destroy the pigs. How would I get it to check to make sure all pigs are destroyed without having to program each object every map?

I just realized I posted this in the wrong area. My mistake.

Use the system condition compare values, object.count=0.

Thanks!