oc实例对象的实例成员的数据存在哪里objc_ivar？objc_object?

struct objc_class {

    Class isa;



    Class super_class;

    const char *name;

    long version;

    long info;

    long instance_size;

    struct objc_ivar_list *ivars;

    struct objc_method_list **methodLists;

    struct objc_cache *cache;

    struct objc_protocol_list *protocols;

}



struct objc_ivar {

    char *ivar_name;

    char *ivar_type;

    int ivar_offset;

}                



struct objc_ivar_list {

    int ivar_count;

    /* variable length structure */

    struct objc_ivar ivar_list[1];

}

typedef struct objc_object {

    Class isa;

} *id;