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From: David Brown <david.brown@hesbynett.no>
Newsgroups: comp.lang.c
Subject: Re: question about nullptr
Date: Tue, 9 Jul 2024 18:19:20 +0200
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On 09/07/2024 14:50, Michael S wrote:
> On Tue, 09 Jul 2024 04:32:50 -0700
> Tim Rentsch <tr.17687@z991.linuxsc.com> wrote:
> 
>> Michael S <already5chosen@yahoo.com> writes:
>>
>>> On Mon, 8 Jul 2024 15:23:47 -0700
>>> "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> wrote:
>>>   
>>>> On 7/8/2024 12:28 PM, Michael S wrote:
>>>>   
>>>>> On Sun, 07 Jul 2024 15:17:34 -0700
>>>>> Keith Thompson <Keith.S.Thompson+u@gmail.com> wrote:
>>>>>   
>>>>>> I just about always use NULL, not 0, when I want a null pointer
>>>>>> constant.  Similarly, I use '\0', not 0, when I want a null
>>>>>> character, 0.0 when I want a floating-point zero, and false when
>>>>>> I want a Boolean zero.  I just like being explicit.
>>>>>
>>>>> Pointer:  I very rarely use NULL.
>>>>> Character:  I never use '\0'.
>>>>
>>>> Not even something like:
>>>>
>>>> #define CLINE 128
>>>>
>>>> char x[CLINE] = { '\0' };
>>>>
>>>> ?
>>>>
>>>> ;^)
>>>
>>> I see nothing special about your case. {0} is the most appropriate.
>>>   
>>
>> Any use of '\0' almost always strikes me as an affectation.  It's
>> like people want to somehow pretend that it's not the same as
>> just 0.
>>
>>> And, BTW, I never use #define for integer constants.
>>
>> What do you do if you need to define a compile-time constant
>> whose value is outside the range of signed int?  With the
>> understanding that the context is C as it is now, and not
>> C++ or some imagined other language.
> 
> In comment above "integer constant" meant "within the range of signed
> int". But let's accept more general meaning. Then, when it happens, I
> have a problem and forced to flex my principles :(
> Luckily, it's pretty rare. I mean, it's pretty rare that the constant
> is both outside the range of signed int and I really really have to
> have it as compile-time constant. More often big numbers like these are
> used in arithmetic/logic, so 'const wide_type' or 'static const
> wide_type' is practically as good as a "real" compile-time constant
> despite being "less constant" in theory.
> 

static const of the appropriate type should be as good as a define'd 
value in almost any circumstance (assuming, of course, an optimising 
compiler).

There are circumstances where you can use an enumeration constant as a 
named integer constant, but where a static const int value cannot be 
used, such as the size of statically allocated arrays.  But you are very 
unlikely to need such a large value to be an integer constant, rather 
than just a value that the compiler sees as a compile-time constant for 
optimisation purposes.

(And C23 helpfully allows enum values that are of larger integer types. 
And also "constexpr" declarations.)