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Re: efficient coding with literals and variables

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On 15/06/16 19:01, Keith Thompson wrote:
> David Brown <david.brown@hesbynett.no> writes:
>> On 14/06/16 21:53, BartC wrote:
> [...]
>>> (I'm not sure I would bother either: if these are constant values known
>>> at compile time, then #define or enums are better ways of denoting a
>>> named constant.)
>>
>> No, #define and enum are /not/ better ways of denoting named constants.
>>   They are sometimes the only way to get what you need, especially in C
>> (in C++, "const int" is more powerful than it is in plain C).  It's okay
>> to say that you /prefer/ to use #define or enum for named constants -
>> but don't make the mistake of thinking your preferences for an extremely
>> simple, limited and flat-structured language is "better" for other
>> people or other purposes.
>
> The problem with const is that it doesn't create a constant expression.
> enum does (though it's limited to constants of type int).
>

Yes, and that is an annoying limitation (C++ improves on that) - which 
is why I said that #define and enum are "sometimes the only way to get 
what you need".  But in other aspects, "const" objects are better - in 
particular, they obey the scoping and parsing rules of C rather than the 
pre-processor, and they have a proper type (rather than being sort-of 
int, sort-of their own enumeration type for enums).

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Re: efficient coding with literals and variables BartC <bc@freeuk.com> - 2016-06-14 20:53 +0100
  Re: efficient coding with literals and variables David Brown <david.brown@hesbynett.no> - 2016-06-15 08:59 +0200
    Re: efficient coding with literals and variables Keith Thompson <kst-u@mib.org> - 2016-06-15 10:01 -0700
      Re: efficient coding with literals and variables David Brown <david.brown@hesbynett.no> - 2016-06-15 19:47 +0200
        Re: efficient coding with literals and variables Keith Thompson <kst-u@mib.org> - 2016-06-15 11:47 -0700
    Re: efficient coding with literals and variables Ike Naar <ike@iceland.freeshell.org> - 2016-06-15 21:23 +0000
      Re: efficient coding with literals and variables David Brown <david.brown@hesbynett.no> - 2016-06-15 23:53 +0200
        Re: efficient coding with literals and variables Ike Naar <ike@iceland.freeshell.org> - 2016-06-15 22:41 +0000
          Re: efficient coding with literals and variables "James R. Kuyper" <jameskuyper@verizon.net> - 2016-06-15 18:54 -0400
            Re: efficient coding with literals and variables Ike Naar <ike@iceland.freeshell.org> - 2016-06-16 05:41 +0000
          Re: efficient coding with literals and variables David Brown <david.brown@hesbynett.no> - 2016-06-16 09:12 +0200
      Re: efficient coding with literals and variables Keith Thompson <kst-u@mib.org> - 2016-06-15 14:53 -0700

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