typedef enum {
 NORTH, SOUTH, EAST, WEST
} Direction;
typedef struct {
 char *description;
 int (*init)(void *self);
 void (*describe)(void *self);
 void (*destroy)(void *self);
 void *(*move)(void *self, Direction direction);
 int (*attack)(void *self, int damage);
} Object;
int Object_init(void *self);
void Object_destroy(void *self);
void Object_describe(void *self);
void *Object_move(void *self, Direction direction);
int Object_attack(void *self, int damage);
void *Object_new(size_t size, Object proto, char *description);
#define NEW(T, N) Object_new(sizeof(T), T##Proto, N)
#define _(N) proto.N