-extern void write_map_objects(struct World * world, void * start, FILE * file);
-extern void read_map_objects(struct World * world, void * start, FILE * file);
+extern uint8_t write_map_objects(struct World * world, void * start,
+ FILE * file);
+extern uint8_t read_map_objects(struct World * world, void * start, FILE * file);