Pointers in comparison expressions

[Andreas Schwab]

"Dave Korn" <dave.korn@artimi.com> writes:

>   Since pointer subtraction is well defined, and it returns an int, then ...
>
> int *a, *b;
>
>   if (a < b)
>     dosomething ();
>
> ... is just the same as ...
>
> int *a, *b;
>
>   if ((b - a) >= 0)
>     dosomething ();

This may not work correctly if ((char*) b - (char*) a) % sizeof int != 0
(which can happen if __alignof__ int < sizeof int).

Andreas.

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Andreas Schwab, SuSE Labs, schwab@suse.de
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