/* visitor patterns in CORBA */

interface undergrad;    /* prototypes - no forward reference */
interface grad;

interface studentvisitor
{
    Object visitu(inout undergrad u);   /* no overloading in CORBA! */
    Object visitg(inout grad g);
};

interface studentvisitee   /* abstract class */
{
    attribute string name;
    attribute double gpa;
    attribute long tuition;
    attribute studentvisitee next;  /* linked list */

    Object accept(in studentvisitor visitor);

    long f();  // test
};


/* visitee subclasses */

interface undergrad : studentvisitee
{
    attribute string major;
};

interface grad : studentvisitee
{
    attribute string thesistopic;
};


/* visitor subclasses don't need new declarations? */

interface printvisitor : studentvisitor {};
interface tuitionadjustor : studentvisitor {};