Messages in this thread | ![/](/images/icornerl.gif) | | From | Darren Williams <> | Date | Tue, 14 Oct 2003 11:32:27 +1000 | Subject | VM code question |
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I have a small question wrt some VM code. source file is include/linux/kernel.h
#define container_of(ptr, type, member) ({ \ const typeof( ((type *)0)->member ) *__mptr = (ptr); \ (type *)( (char *)__mptr - offsetof(type,member) );})
what is the use of the 0 (zero) in the typeof? I am thinking that we are casting 0 to (type *) then referencing 'member' of 'type', however why do we require the 0 ?
Just curious
-------------------------------------------------- Darren Williams <dsw@gelato.unsw.edu.au> Gelato@UNSW <www.gelato.unsw.edu.au> -------------------------------------------------- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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