[cfe-dev] id and ObjC interfaces

[Jean-Daniel Dupas]

Le 25 avr. 09 à 06:04, Zhongxing Xu a écrit :

> Hi all,
>
> In clang, type 'id' is implemented as 'typedef struct objc_object *'.
> And 'id' can points to any ObjC objects. Does that mean that all ObjC
> interfaces inherits 'struct objc_object' implicitly?
>

I don't know how clang handle this but AFAK, the first ivar of a root  
class must be a pointer on the object class (usually named isa) (this  
is the case for NSObject and NSProxy for example).
So, an interface should not inherit struct objc_object, else the isa  
pointer will be defined twice.