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From: Keith Thompson <kst-u@mib.org>
Newsgroups: comp.lang.c
Subject: Re: I think this is an impossible assignment...could you help?
Date: Wed, 31 Aug 2011 11:44:52 -0700
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"BartC" <bc@freeuk.com> writes:
> "Keith Thompson" <kst-u@mib.org> wrote in message
> news:lnmxeptv4b.fsf@nuthaus.mib.org...
>> "BartC" <bc@freeuk.com> writes:
>>> "Jack" <spamtrap@trashcan.invalid> wrote in message
>>> news:j3jj2t$eq3$1@speranza.aioe.org...
>>>
>>>> #include
>>>> #define INVALID     0x80000000
>> [...]
>>>> {long num, i;
>> [...]
>>>>   { if (num == INVALID)
>>
>> If long is 32 bits, then 0x80000000 is outside the range of long.
>> How about
>>
>>    #define INVALID LONG_MIN
>> ?
>
> I always think of 'long' as unsigned (because outside C, that's how I
> use it), and I didn't see that. Similarly when I saw LONG_MIN I
> immediately thought zero!
>
> But yes that would be a better signalling value.

(You know about "unsigned long", right?)

-- 
Keith Thompson (The_Other_Keith) kst-u@mib.org  <http://www.ghoti.net/~kst>
Nokia
"We must do something.  This is something.  Therefore, we must do this."
    -- Antony Jay and Jonathan Lynn, "Yes Minister"