class Reservation
{
public:
int resource_type;
int resource_id;
int user_id;
time_t range[2];
};
...
int Reservation::*t = &Reservation::resource_type;
Reservation r;
int resource_type = r.*t;
(b)
class User
{
public:
std::string name;
};
class Reservation_Hack
{
public:
int resource_type;
int resource_id;
User user;
time_t range[2];
};