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Date:   Mon, 7 Mar 2022 11:49:03 +0200
From:   Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To:     Jakob Koschel <jakobkoschel@gmail.com>
Cc:     Linus Torvalds <torvalds@linux-foundation.org>,
        linux-kernel@vger.kernel.org,
        Andrew Morton <akpm@linux-foundation.org>,
        Greg Kroah-Hartman <greg@kroah.com>,
        Mike Rapoport <rppt@kernel.org>,
        Brian Johannesmeyer <bjohannesmeyer@gmail.com>,
        Cristiano Giuffrida <c.giuffrida@vu.nl>,
        "Bos, H.J." <h.j.bos@vu.nl>
Subject: Re: [PATCH] list: always set pos in list_prepare_entry()
Message-ID: <YiXVD8O3qyDEOGni@smile.fi.intel.com>
References: <20220306162635.2930407-1-jakobkoschel@gmail.com>
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On Sun, Mar 06, 2022 at 05:26:35PM +0100, Jakob Koschel wrote:
> In order to assign the result from list_prepare_entry() to another
> variable, it should also be set when pos != NULL.
> 
> This will be useful once the list iterator is no longer used after
> the loop.

...

>  #define list_prepare_entry(pos, head, member) \
> -	((pos) ? : list_entry(head, typeof(*pos), member))
> +	((pos) ? pos : list_entry(head, typeof(*pos), member))

I'm not sure why then we have () surrounding first pos.

Am I right that the original is an equivalent to

	((pos) ? (pos) : list_entry(head, typeof(*pos), member))

?

Then what the difference is made by not using parentheses?

-- 
With Best Regards,
Andy Shevchenko