// Cross cutting aspects of the program:  (for base aop18.java)

aspect trace // trace the construction of each object, plus run function
{
    // after advice
    after(Object c) : (execution(student+.new(..)) ||
		       execution(pc.new(..)) || execution(vehicle.new(..)))
	&& target(c) && !adviceexecution()
	{
	    System.out.println("Object created: "+c );
	}
}//trace

/*
    executiong(student+.new(.._)) refers to the joinpoint where
a new instance of student, or subclass of student is being created.
'+' includes subclass and new(..) refers to any constructor.  If we want
to refer a specific constructor, we have to specify its signature more
carefully: new(int) or new(String,..)  

Note that unlike the other advice, here we use 'execution' instead of 'call':
There is no 'target' object being created at the call site until the 
constructor call returns.  Generally, use 'execution' instead of 'call'
to refer to calling a constructor, or calling main. If you say
after(...) : call(public static *.void(main(..)), your advice will
never execute because the program doesn't exist anymore after main.
*/