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Re: is "x *= ++f * ++f" a valid statement ?

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Keith Thompson <Keith.S.Thompson+u@gmail.com> writes:

> Tim Rentsch <tr.17687@z991.linuxsc.com> writes:
>
>> Keith Thompson <Keith.S.Thompson+u@gmail.com> writes:
>>
>>> James Kuyper <jameskuyper@alumni.caltech.edu> writes:
>>
>> [...]
>>
>>>> A minor detail is that a variable must be declared, whereas memory
>>>> locations can, for instance, be part of allocated memory for which
>>>> no declaration exists - it is still undefined behavior to write
>>>> code that applies unsequence side-effects to such memory locations.
>>>
>>> Digression:  I'm not even sure what "variable" means in C++.  The
>>> standard defines the term, but not in a way that really tells us
>>> what it means.
>>>
>>> "A *variable* is introduced by the declaration of a reference other
>>> than a non-static data member or of an object.  The variable's name,
>>> if any, denotes the reference or object."
>>
>> What part do you find confusing or hard to understand?
>
> The missing part that should tell us what a variable *is*.
>
> It says that certain declarations "introduce" a variable.  That's a
> statement about variables, but it doesn't say what a variable is.
>
> Given:
>
>     int n;
>
> we know that the declaration introduces a variable.  Is the object
> itself a "variable"?  That's the obvious meaning, and it's consistent
> with what the standard says.  Or is a "variable" some kind of logical
> binding between an object and a name?  That's also consistent with
> what the standard says.  Under the latter interpretation, the
> "variable" has a name, and that name denotes an object, but the
> variable is not the object.
>
> Given the above declaration, is the introduced variable an object?
> If so, or if not, how does your answer follow from what the standard
> says?

Even moreso than the C standard, the C++ standard needs to be read
holistically.  That may be a damning commentary on the quality of
writing in the C++ standard, but I think it matches the reality.

Given that, when confronted with a question like the ones you ask
about the term "variable", a natural course of action to find
answers to these questions might be to open the C++ standard in
a PDF viewer, and use the viewer's search facility to look at
places where the term in question is used.  The more of those that
can be looked at, the more likely it is that one will be able to
discern answers to such questions.  That's probably what I would
do if I felt I needed a better understanding of, for example, what
the term "variable" is supposed to mean.

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is "x *= ++f * ++f" a valid statement ? Bonita Montero <Bonita.Montero@gmail.com> - 2024-05-23 16:14 +0200
  Re: is "x *= ++f * ++f" a valid statement ? Andrey Tarasevich <andreytarasevich@hotmail.com> - 2024-06-18 18:53 -0700
    Re: is "x *= ++f * ++f" a valid statement ? Bonita Montero <Bonita.Montero@gmail.com> - 2024-06-19 17:40 +0200
    Re: is "x *= ++f * ++f" a valid statement ? PLO olcott <polcott333@gmail.com> - 2024-06-21 16:55 -0500
      Re: is "x *= ++f * ++f" a valid statement ? PLO Richard Damon <richard@damon-family.org> - 2024-06-21 18:10 -0400
        Re: is "x *= ++f * ++f" a valid statement ? PLO olcott <polcott333@gmail.com> - 2024-06-21 18:06 -0500
          Re: is "x *= ++f * ++f" a valid statement ? PLO Richard Damon <richard@damon-family.org> - 2024-06-21 20:14 -0400
          Re: is "x *= ++f * ++f" a valid statement ? PLO Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-06-21 17:35 -0700
            Re: is "x *= ++f * ++f" a valid statement ? PLO olcott <polcott333@gmail.com> - 2024-06-21 22:58 -0500
              Re: is "x *= ++f * ++f" a valid statement ? PLO Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-06-21 23:18 -0700
                Re: is "x *= ++f * ++f" a valid statement ? PLO olcott <polcott333@gmail.com> - 2024-06-22 07:38 -0500
                Re: is "x *= ++f * ++f" a valid statement ? PLO Richard Damon <richard@damon-family.org> - 2024-06-22 09:45 -0400
                Re: is "x *= ++f * ++f" a valid statement ? PLO olcott <polcott333@gmail.com> - 2024-06-22 09:13 -0500
                Re: is "x *= ++f * ++f" a valid statement ? PLO Richard Damon <richard@damon-family.org> - 2024-06-22 10:23 -0400
                Re: is "x *= ++f * ++f" a valid statement ? PLO Mikko <mikko.levanto@iki.fi> - 2024-06-23 11:48 +0300
                Re: is "x *= ++f * ++f" a valid statement ? PLO Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-06-22 17:54 -0700
          Re: is "x *= ++f * ++f" a valid statement ? PLO James Kuyper <jameskuyper@alumni.caltech.edu> - 2024-06-21 23:42 -0400
            Re: is "x *= ++f * ++f" a valid statement ? PLO olcott <polcott333@gmail.com> - 2024-06-21 23:02 -0500
              Re: is "x *= ++f * ++f" a valid statement ? PLO David Brown <david.brown@hesbynett.no> - 2024-06-22 13:09 +0200
                Re: is "x *= ++f * ++f" a valid statement ? PLO olcott <polcott333@gmail.com> - 2024-06-22 07:40 -0500
                Re: is "x *= ++f * ++f" a valid statement ? PLO Richard Damon <richard@damon-family.org> - 2024-06-22 09:56 -0400
                Re: is "x *= ++f * ++f" a valid statement ? PLO "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-06-22 12:14 -0700
                Re: is "x *= ++f * ++f" a valid statement ? PLO David Brown <david.brown@hesbynett.no> - 2024-06-22 16:52 +0200
                Re: is "x *= ++f * ++f" a valid statement ? PLO olcott <polcott333@gmail.com> - 2024-06-22 11:27 -0500
                Re: is "x *= ++f * ++f" a valid statement ? PLO Richard Damon <richard@damon-family.org> - 2024-06-22 13:20 -0400
                Re: is "x *= ++f * ++f" a valid statement ? PLO Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-06-22 17:55 -0700
                Re: is "x *= ++f * ++f" a valid statement ? PLO David Brown <david.brown@hesbynett.no> - 2024-06-23 14:46 +0200
              Re: is "x *= ++f * ++f" a valid statement ? PLO James Kuyper <jameskuyper@alumni.caltech.edu> - 2024-06-22 15:48 -0400
  Re: is "x *= ++f * ++f" a valid statement ? Richard Damon <richard@damon-family.org> - 2024-06-18 22:27 -0400
  Re: is "x *= ++f * ++f" a valid statement ? olcott <polcott333@gmail.com> - 2024-06-22 21:51 -0500
    Re: is "x *= ++f * ++f" a valid statement ? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-06-22 21:51 -0700
    Re: is "x *= ++f * ++f" a valid statement ? Richard Damon <richard@damon-family.org> - 2024-06-23 07:32 -0400
      Re: is "x *= ++f * ++f" a valid statement ? olcott <polcott333@gmail.com> - 2024-06-23 07:59 -0500
        Re: is "x *= ++f * ++f" a valid statement ? Richard Damon <richard@damon-family.org> - 2024-06-23 14:25 -0400
          Re: is "x *= ++f * ++f" a valid statement ? olcott <polcott333@gmail.com> - 2024-06-23 14:18 -0500
            Re: is "x *= ++f * ++f" a valid statement ? Richard Damon <richard@damon-family.org> - 2024-06-23 16:23 -0400
              Re: is "x *= ++f * ++f" a valid statement ? David Brown <david.brown@hesbynett.no> - 2024-06-24 09:11 +0200
  Re: is "x *= ++f * ++f" a valid statement ? what@tf.com (testuseri2p) - 2024-07-22 17:51 +0000
    Re: is "x *= ++f * ++f" a valid statement ? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-07-22 14:58 -0700
    Re: is "x *= ++f * ++f" a valid statement ? James Kuyper <jameskuyper@alumni.caltech.edu> - 2024-07-22 21:57 -0400
      Re: is "x *= ++f * ++f" a valid statement ? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-07-22 20:40 -0700
        Re: is "x *= ++f * ++f" a valid statement ? James Kuyper <jameskuyper@alumni.caltech.edu> - 2024-07-23 10:15 -0400
        Re: is "x *= ++f * ++f" a valid statement ? Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-07-23 07:28 -0700
          Re: is "x *= ++f * ++f" a valid statement ? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-07-23 14:42 -0700
            Re: is "x *= ++f * ++f" a valid statement ? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-07-23 15:05 -0700
              Re: is "x *= ++f * ++f" a valid statement ? Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-08-11 06:22 -0700
                Re: is "x *= ++f * ++f" a valid statement ? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-08-11 14:09 -0700
            Re: is "x *= ++f * ++f" a valid statement ? Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-08-11 06:11 -0700
              Re: is "x *= ++f * ++f" a valid statement ? Chris Ahlstrom <OFeem1987@teleworm.us> - 2024-08-11 09:25 -0400
              Re: is "x *= ++f * ++f" a valid statement ? James Kuyper <jameskuyper@alumni.caltech.edu> - 2024-08-11 14:17 -0400
      Re: is "x *= ++f * ++f" a valid statement ? Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-07-23 07:32 -0700
    Re: is "x *= ++f * ++f" a valid statement ? Andrey Tarasevich <andreytarasevich@hotmail.com> - 2024-07-22 19:53 -0700
    Re: is "x *= ++f * ++f" a valid statement ? James Kuyper <jameskuyper@alumni.caltech.edu> - 2024-07-23 10:01 -0400

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