Re: Once again pointer to first element vs pointer to array cast

Szabolcs Borsanyi wrote:
> I know that this topic has been discussed a lot, still I'd appreciate
> a clear cut (and correct) answer:
> I pass a multidimensional array to a function, which is defined as
> int f(int a[10][10])
> {
>   int *b=(void*)a;
>   int *c=a[0];
>   /*...*/
> }
> Now the questions come:
> - Is it guaranteed that b and c points to the same object (or is this
> implementation defined)?

This is the only guarantee you have with that kind of conversion:
N869
        6.3.2.3  Pointers

        [#1] A pointer to void may be converted to or from a pointer
        to  any  incomplete  or  object  type.   A  pointer  to  any
        incomplete or object type may be converted to a  pointer  to
        void  and  back again; the result shall compare equal to the
        original pointer.

> - Is it always true that a[1][1] refers to the same object as c[11] ?
> (There is no hole)

c[11] is undefined.

> - Does dereferencing b violate any aliasing rule?


-- 
pete