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Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding

From James Kuyper <jameskuyper@alumni.caltech.edu>
Newsgroups comp.lang.c++
Subject Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding
Date 2019-11-22 23:56 -0500
Organization A noiseless patient Spider
Message-ID <qrae5f$am1$1@dont-email.me> (permalink)
References (9 earlier) <qr8jeg$v7n$1@dont-email.me> <qr8pu5$657$1@dont-email.me> <qr99qg$ats$1@dont-email.me> <qr9bte$noa$1@dont-email.me> <qr9qom$me2$1@dont-email.me>

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On 11/22/19 6:25 PM, Soviet_Mario wrote:
> Il 22/11/19 20:11, James Kuyper ha scritto:
>> On 11/22/19 1:35 PM, Soviet_Mario wrote:
>>> Il 22/11/19 15:04, David Brown ha scritto:
>> ...
>>> I have abandoned the unsigned Bit_Field : 8 solution as soon
>>> as you (a lot of people) stated that u_int_8 MUST have
>>
>> uint8_t
> 
> here the macro or typedef is
> 
> u_int8_t actually

Everyone who's been talking with you about this subject has been talking
about std::uint8_t from <cstdint>. If you're talking about something
else, you need to identify what it is and where is it is declared.

In gcc, and in many other compilers as well, there's a command line
option (-E in gcc) that produces output after pre-processing, but before
any other of the translation phases, but with #line directives inserted
to make sure that if you compile the output from -E, any resulting error
messages will refer to the correct file.
Compile one of the modules that uses u_int8_t using -E. Search the
output for the first occurrence of u_int8_t, which should be a typedef
declaration. What file is referred to by the last #line directive
preceding that declaration?

...
>>> 	u_int_32  AllChannels;
>>
>> uint_32
> 
> maybe QT headers decorate differently

A search of the QT online reference manual for u_int8_t turns up nothing:
<https://doc.qt.io/qt-5/search-results.html?q=%22u_int8_t%22>

Nor do I get anything from u_int_32:
<https://doc.qt.io/qt-5/search-results.html?q=%22u_int_32%22>

Whatever is the source of this typedef, I don't think it's QT.

>>>> in the sense of having unaligned data that would have
>>>> padding in a normal struct.  I have seen no answer to this (unless it is
>>>> later in this post), despite asking this /crucial/ question.
>>>
>>> the files are packed.
>>
>> OK - which fields are positioned differently from the way they would be
>> positioned if not packed?
> 
> as I said, I do not have a working complete program yet, and 
> I hope to get to a scenario where this wrong situation is 
> avoided at all

I think you can avoid it perfectly without doing anything at all about
it, because it can't occur. I recommend not wasting any more time
worrying about it until you can come up with a plausible reason for
doing so.

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Thread

[QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding Soviet_Mario <SovietMario@CCCP.MIR> - 2019-11-20 19:55 +0100
  Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding Soviet_Mario <SovietMario@CCCP.MIR> - 2019-11-20 20:12 +0100
    Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding Keith Thompson <kst-u@mib.org> - 2019-11-20 22:33 -0800
  Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding Soviet_Mario <SovietMario@CCCP.MIR> - 2019-11-20 20:22 +0100
  Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding Jorgen Grahn <grahn+nntp@snipabacken.se> - 2019-11-20 19:34 +0000
    Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding Soviet_Mario <SovietMario@CCCP.MIR> - 2019-11-21 00:54 +0100
      Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding Öö Tiib <ootiib@hot.ee> - 2019-11-20 16:27 -0800
      Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding Manfred <invalid@add.invalid> - 2019-11-21 01:48 +0100
        Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding Soviet_Mario <SovietMario@CCCP.MIR> - 2019-11-21 04:09 +0100
      Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding James Kuyper <jameskuyper@alumni.caltech.edu> - 2019-11-20 17:44 -0800
        Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding Soviet_Mario <SovietMario@CCCP.MIR> - 2019-11-21 04:14 +0100
  Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding David Brown <david.brown@hesbynett.no> - 2019-11-20 22:03 +0100
    Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding Soviet_Mario <SovietMario@CCCP.MIR> - 2019-11-21 01:00 +0100
      Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding David Brown <david.brown@hesbynett.no> - 2019-11-21 13:22 +0100
        Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding Keith Thompson <kst-u@mib.org> - 2019-11-21 11:30 -0800
          Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding David Brown <david.brown@hesbynett.no> - 2019-11-21 22:54 +0100
  Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding Paavo Helde <myfirstname@osa.pri.ee> - 2019-11-20 23:28 +0200
  Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding James Kuyper <jameskuyper@alumni.caltech.edu> - 2019-11-20 15:48 -0800
  Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding Reinhardt Behm <rbehm@hushmail.com> - 2019-11-21 10:33 +0800
    Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding David Brown <david.brown@hesbynett.no> - 2019-11-21 13:25 +0100
  Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding Keith Thompson <kst-u@mib.org> - 2019-11-20 22:32 -0800
    Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding Keith Thompson <kst-u@mib.org> - 2019-11-20 22:43 -0800
      Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding Soviet_Mario <SovietMario@CCCP.MIR> - 2019-11-21 12:53 +0100
        Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding Paavo Helde <myfirstname@osa.pri.ee> - 2019-11-21 18:20 +0200
          Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding Soviet_Mario <SovietMario@CCCP.MIR> - 2019-11-21 18:07 +0100
          Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding Mr Flibble <flibbleREMOVETHISBIT@i42.co.uk> - 2019-11-21 17:34 +0000
          Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding Christian Gollwitzer <auriocus@gmx.de> - 2019-11-22 07:26 +0100
            Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding Keith Thompson <kst-u@mib.org> - 2019-11-22 00:37 -0800
              Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding David Brown <david.brown@hesbynett.no> - 2019-11-22 10:10 +0100
                Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding Öö Tiib <ootiib@hot.ee> - 2019-11-22 02:23 -0800
                Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding David Brown <david.brown@hesbynett.no> - 2019-11-22 12:38 +0100
                Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding Manfred <noname@add.invalid> - 2019-11-22 17:13 +0100
                Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding David Brown <david.brown@hesbynett.no> - 2019-11-22 18:48 +0100
                Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding James Kuyper <jameskuyper@alumni.caltech.edu> - 2019-11-22 10:49 -0500
                Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding James Kuyper <jameskuyper@alumni.caltech.edu> - 2019-11-22 10:52 -0500
                Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding Tim Rentsch <tr.17687@z991.linuxsc.com> - 2019-11-28 12:51 -0800
              Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding Soviet_Mario <SovietMario@CCCP.MIR> - 2019-11-22 11:20 +0100
                Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding Keith Thompson <kst-u@mib.org> - 2019-11-22 10:00 -0800
            Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding David Brown <david.brown@hesbynett.no> - 2019-11-22 09:37 +0100
              Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding Öö Tiib <ootiib@hot.ee> - 2019-11-22 01:37 -0800
                Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding David Brown <david.brown@hesbynett.no> - 2019-11-22 11:40 +0100
                Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding Öö Tiib <ootiib@hot.ee> - 2019-11-22 04:55 -0800
                Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding David Brown <david.brown@hesbynett.no> - 2019-11-22 15:18 +0100
                Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding Öö Tiib <ootiib@hot.ee> - 2019-11-22 07:23 -0800
                Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding David Brown <david.brown@hesbynett.no> - 2019-11-22 16:34 +0100
                Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding scott@slp53.sl.home (Scott Lurndal) - 2019-11-22 15:16 +0000
                Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding Öö Tiib <ootiib@hot.ee> - 2019-11-23 05:11 -0800
                Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding James Kuyper <jameskuyper@alumni.caltech.edu> - 2019-11-22 10:56 -0500
                Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding Öö Tiib <ootiib@hot.ee> - 2019-11-23 07:03 -0800
              Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding Soviet_Mario <SovietMario@CCCP.MIR> - 2019-11-22 11:31 +0100
                Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding David Brown <david.brown@hesbynett.no> - 2019-11-22 12:23 +0100
                Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding Soviet_Mario <SovietMario@CCCP.MIR> - 2019-11-22 13:14 +0100
                Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding David Brown <david.brown@hesbynett.no> - 2019-11-22 15:04 +0100
                Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding Soviet_Mario <SovietMario@CCCP.MIR> - 2019-11-22 19:35 +0100
                Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding James Kuyper <jameskuyper@alumni.caltech.edu> - 2019-11-22 14:11 -0500
                Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding Soviet_Mario <SovietMario@CCCP.MIR> - 2019-11-23 00:25 +0100
                Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding James Kuyper <jameskuyper@alumni.caltech.edu> - 2019-11-22 23:56 -0500
                Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding Soviet_Mario <SovietMario@CCCP.MIR> - 2019-11-23 11:12 +0100
                Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding Paavo Helde <myfirstname@osa.pri.ee> - 2019-11-23 14:51 +0200
                Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding James Kuyper <jameskuyper@alumni.caltech.edu> - 2019-11-25 11:45 -0500
                Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding Keith Thompson <kst-u@mib.org> - 2019-11-22 22:04 -0800
                Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding Soviet_Mario <SovietMario@CCCP.MIR> - 2019-11-23 11:26 +0100
                Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding Keith Thompson <kst-u@mib.org> - 2019-11-23 12:27 -0800
                Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding Soviet_Mario <SovietMario@CCCP.MIR> - 2019-11-24 00:54 +0100
                Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding Keith Thompson <kst-u@mib.org> - 2019-11-23 17:06 -0800
                Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding Soviet_Mario <SovietMario@CCCP.MIR> - 2019-11-24 12:10 +0100
  Re: [QT creator on "nix"] - getting a strict 8 bit (1 byte) array with no padding Tim Rentsch <tr.17687@z991.linuxsc.com> - 2019-11-28 13:21 -0800

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