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Re: bit-fields of type unsigned long and unsigned long long

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David Brown <david.brown@hesbynett.no> writes:
> On 22/06/2021 16:49, Philipp Klaus Krause wrote:
>> Since bit-fields of type unsigned long and unsigned long long are
>> useful, commonly suppoted by implementations, and commonly used, I'd
>> like to see the standard support them.
>
> The standard /does/ support them - it simply does not mandate that an
> implementation supports them.  It's good to be accurate in your wording
> for a proposal like that.

In the proposal, I suggest:

    This adds unsigned long and unsigned long long to the +required+
    supported types for bit-fields.

> In my own code, I don't believe I have ever had need for types longer
> than "unsigned int" in bitfields - though I have certainly used the type
> "uint32_t" which happens to be "unsigned long" on several targets even
> though "unsigned int" is the same size.
>
> But I have a lot more use of smaller integer types.  And I use
> enumerated types in bitfields too, though these usually require a
> minimum size matching "int" (unless you use compiler-specific extensions
> to change that).
>
> I would suggest that it is pointless to add to the list of types
> mandated in the C standard here.  Rather, it should simply say that a
> bit-field shall have "an integer type".  That covers all sizes, shorter
> than int as well as longer, signed as well as unsigned.  After all,
> pretty much any serious modern C compiler will already support all
> integer types here.
>
> And I would also be even happier with "an integer type or enumerated type".

I agree.  If you're going to mandate support for additional types, why
not go all the way?

Currently, plain int bit fields have implementation-defined signedness.
I'm not a big fan of that rule, but logically it should be extended to
bit fields of other integer types specified without a "signed" or
"unsigned" keyword -- except that a plain char bit field should IMHO
have the same signedness as plain char.

Signed bit fields are questionably useful, but support for them is
already required, and I'm sure there's code that depends on them.

>> Here's  a draft of a proposal for that:
>> 
>> http://www.colecovision.eu/stuff/proposal-unsigned-long-bit-field.html

"support" is misspelled in the Justification section.

-- 
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
Working, but not speaking, for Philips Healthcare
void Void(void) { Void(); } /* The recursive call of the void */

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bit-fields of type unsigned long and unsigned long long Philipp Klaus Krause <pkk@spth.de> - 2021-06-22 16:49 +0200
  Re: bit-fields of type unsigned long and unsigned long long David Brown <david.brown@hesbynett.no> - 2021-06-22 17:18 +0200
    Re: bit-fields of type unsigned long and unsigned long long Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-06-22 11:17 -0700
      Re: bit-fields of type unsigned long and unsigned long long Philipp Klaus Krause <pkk@spth.de> - 2021-06-23 08:25 +0200
        Re: bit-fields of type unsigned long and unsigned long long David Brown <david.brown@hesbynett.no> - 2021-06-23 08:59 +0200
          Re: bit-fields of type unsigned long and unsigned long long Philipp Klaus Krause <pkk@spth.de> - 2021-06-23 13:12 +0200
            Re: bit-fields of type unsigned long and unsigned long long David Brown <david.brown@hesbynett.no> - 2021-06-23 14:14 +0200
              Re: bit-fields of type unsigned long and unsigned long long Philipp Klaus Krause <pkk@spth.de> - 2021-06-23 17:45 +0200
                Re: bit-fields of type unsigned long and unsigned long long Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-06-23 10:22 -0700
                Re: bit-fields of type unsigned long and unsigned long long Philipp Klaus Krause <pkk@spth.de> - 2021-06-23 19:52 +0200
                Re: bit-fields of type unsigned long and unsigned long long Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-06-23 16:12 -0700
                Re: bit-fields of type unsigned long and unsigned long long David Brown <david.brown@hesbynett.no> - 2021-06-24 10:41 +0200
                Re: bit-fields of type unsigned long and unsigned long long David Brown <david.brown@hesbynett.no> - 2021-06-24 10:32 +0200
        Re: bit-fields of type unsigned long and unsigned long long Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-06-23 00:39 -0700
  Re: bit-fields of type unsigned long and unsigned long long Philipp Klaus Krause <pkk@spth.de> - 2021-06-23 13:22 +0200
    Re: bit-fields of type unsigned long and unsigned long long Philipp Klaus Krause <pkk@spth.de> - 2021-06-23 18:27 +0200
  Re: bit-fields of type unsigned long and unsigned long long Tim Rentsch <tr.17687@z991.linuxsc.com> - 2021-06-23 10:53 -0700
    Re: bit-fields of type unsigned long and unsigned long long Philipp Klaus Krause <pkk@spth.de> - 2021-06-23 20:13 +0200
      Re: bit-fields of type unsigned long and unsigned long long Tim Rentsch <tr.17687@z991.linuxsc.com> - 2021-06-24 11:48 -0700
        Re: bit-fields of type unsigned long and unsigned long long Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-06-24 12:23 -0700
          Re: bit-fields of type unsigned long and unsigned long long David Brown <david.brown@hesbynett.no> - 2021-06-24 22:40 +0200
          Re: bit-fields of type unsigned long and unsigned long long Tim Rentsch <tr.17687@z991.linuxsc.com> - 2021-07-10 09:13 -0700
        Re: bit-fields of type unsigned long and unsigned long long Philipp Klaus Krause <pkk@spth.de> - 2021-06-24 22:14 +0200
          Re: bit-fields of type unsigned long and unsigned long long Tim Rentsch <tr.17687@z991.linuxsc.com> - 2021-07-10 09:23 -0700
    Re: bit-fields of type unsigned long and unsigned long long David Brown <david.brown@hesbynett.no> - 2021-06-24 11:02 +0200
      Re: bit-fields of type unsigned long and unsigned long long Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-06-24 11:06 -0700
        Re: bit-fields of type unsigned long and unsigned long long David Brown <david.brown@hesbynett.no> - 2021-06-24 23:11 +0200
          Re: bit-fields of type unsigned long and unsigned long long Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-06-24 15:16 -0700
            Re: bit-fields of type unsigned long and unsigned long long David Brown <david.brown@hesbynett.no> - 2021-06-25 10:43 +0200
              Re: bit-fields of type unsigned long and unsigned long long Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-06-25 02:02 -0700
                Re: bit-fields of type unsigned long and unsigned long long David Brown <david.brown@hesbynett.no> - 2021-06-25 13:54 +0200
                Re: bit-fields of type unsigned long and unsigned long long Ben Bacarisse <ben.usenet@bsb.me.uk> - 2021-06-25 13:07 +0100
                Re: bit-fields of type unsigned long and unsigned long long David Brown <david.brown@hesbynett.no> - 2021-06-25 15:17 +0200
                Re: bit-fields of type unsigned long and unsigned long long Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-06-25 08:22 -0700
                Re: bit-fields of type unsigned long and unsigned long long David Brown <david.brown@hesbynett.no> - 2021-06-25 18:22 +0200
                Re: bit-fields of type unsigned long and unsigned long long Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-06-25 13:28 -0700
                Re: bit-fields of type unsigned long and unsigned long long Ben Bacarisse <ben.usenet@bsb.me.uk> - 2021-06-25 19:12 +0100
                Re: bit-fields of type unsigned long and unsigned long long Tim Rentsch <tr.17687@z991.linuxsc.com> - 2021-07-10 08:58 -0700
                Re: bit-fields of type unsigned long and unsigned long long Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-06-25 08:09 -0700
              Re: bit-fields of type unsigned long and unsigned long long Philipp Klaus Krause <pkk@spth.de> - 2021-06-25 14:43 +0200
                Re: bit-fields of type unsigned long and unsigned long long David Brown <david.brown@hesbynett.no> - 2021-06-25 15:33 +0200
                Re: bit-fields of type unsigned long and unsigned long long Jakob Bohm <jb-usenet@wisemo.com.invalid> - 2021-07-06 23:18 +0200

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