err = err | write_map_objects(world, world->monster, file);
err = err | write_map_objects(world, world->item, file);
exit_err(err, world, err_msg);
err = err | write_map_objects(world, world->monster, file);
err = err | write_map_objects(world, world->item, file);
exit_err(err, world, err_msg);