Re: [RFC PATCH 1/5] builtin/checkout: avoid usage of '!!'

From: Kaartic Sivaraam <kaarticsivaraam91196@gmail.com>
Date: Sep 23, 2017, 12:17 UTC
Message-ID: <de378f54-1c6f-327e-3f61-f8b215cfe203@gmail.com>
In-Reply-To: <xmqqlgl8n8fn.fsf@gitster.mtv.corp.google.com>

On Thursday 21 September 2017 07:01 AM, Junio C Hamano wrote:

Show 6 quoted lines

> What does "with arithmetic constructs" mean? Would it refer to
> things like
>
> 	!!i != !!(j + 3)
>
> that unnecessarily obfuscates what is going on?

Thanks that clears the confusion because I haven't seen constructs like this before (who would even do something like this?)

Show 9 quoted lines

> The primary reason why !!ptr is good in the code that this patch
> touches is because what is doubly negated is a pointer, not an
> integer or other things.  The called function does *not* limit its
> input to 0 or 1 (it wants 0 for false and everything else for true),
> so we wouldn't be doing !!i if what we are passing is already an
> integer.  But we cannot just pass a pointer to such a parameter
> without getting the compiler upset.
>
>

Done. So I'll drop this patch.

--- Kaartic