Re: C Construction Problem

From	Tim Rentsch <txr@alumni.caltech.edu>
Newsgroups	comp.lang.c
Subject	Re: C Construction Problem
Date	2018-03-17 10:29 -0700
Organization	A noiseless patient Spider
Message-ID	<kfnzi36objt.fsf@x-alumni2.alumni.caltech.edu> (permalink)
References	(12 earlier) <ffge55Fs83qU1@mid.individual.net> <kfnwoyzrmvb.fsf@x-alumni2.alumni.caltech.edu> <a21a35eb-498d-4db2-9d72-08e8e8485269@googlegroups.com> <kfntvtxqxo6.fsf@x-alumni2.alumni.caltech.edu> <e1e345da-d15d-4276-88e0-2c6ef7de04d1@googlegroups.com>

Show all headers | View raw

jameskuyper@verizon.net writes:

> On Saturday, March 3, 2018 at 5:08:23 AM UTC-5, Tim Rentsch wrote:
>
>> jameskuyper@verizon.net writes:
>>
>>> On Tuesday, February 27, 2018 at 1:02:54 AM UTC-5, Tim Rentsch wrote:
>>>
>>>> Ian Collins <ian-news@hotmail.com> writes:
>>>>
>>>>> Due to C++11 using C99 rather than C89 as its base, [...]
>>>>
>>>> In C++11 and later, C++ uses the C99 library as its base
>>>> library.  It does not use the C99 language as its base
>>>> language.
>>>
>>> "C ++ is a general purpose programming language based on the C
>>> programming language as described in ISO/IEC 9899:2011 Programming
>>> languages ?  C (hereinafter referred to as the C standard).  In
>>> addition to the facilities provided by C, C ++ provides ..."
>>> (n4659.pdf 1p2).
>>>
>>> n3690.pdf refers to 9899:1999 instead of 9899:2011.
>>>
>>> Are you making a distinction between saying "C++ is ... based on
>>> ...  ISO/IEC 9899:1999", and "C99 is the base language for C++"?
>
> I'm presuming, from the nature of your reply below, that your answer to
> that question, had you bothered to make one, would have been "No".  Let
> me know (by explicitly stating what your answer would actually have
> been) if I'm wrong about that.

I am neither making a distinction nor not making a distinction.
I didn't understand how your question related to my statement so
I simply tried to explain that earlier statement further.

>>> If so, could you explain that distinction?
>>
>> C99 has variable length arrays.  C++ does not.
>>
>> C99 has designated initializers.  C++ does not.
>>
>> C99 has compound literals.  C++ does not.
>>
>> C99 has inline functions.  C++ also has inline functions,
>> but with different semantics.
>>
>> C11 has anonymous structs and unions.  C++ does not.
>>
>> C11 has _Generic.  C++ does not.
>>
>> There are other differences;  those are some of the more
>> obvious ones.
>
> Let me extend that list for you.  I took the list of changes from C90
> listed in the C11 foreword, and removed those parts that involved the C
> standard library.  All of the following are C11 differences from C90 that
> are either not present, or implemented differently, in C++17:
>
> ? querying and specifying alignment of objects
> ? no-return functions
> ? more precise aliasing rules via effective type
> ? restricted pointers
> ? static and type qualifiers in parameter array declarators
> ? complex (and imaginary) support in <complex.h>
> ? type-generic math macros in <tgmath.h>
> ? increased minimum translation limits
> ? hexadecimal floating-point constants and %a and %A printf/scanf
> conversion specifiers
> ? IEC 60559 (also known as IEC 559 or IEEE arithmetic) support
> ? new structure type compatibility rules (tag compatibility)
> ? additional predefined macro names
> ? LIA compatibility annex

This list includes some library features and also is incomplete
with respect to language features.

> However, even with those additions, that list still represent only a
> tiny fraction of the total list of features of C11.

Yes, but a large fraction of the differences between C11 and C90,
which is the relevant metric when deciding between whether the
C++ language is more aptly described as based on the C90 language
or the C11 language.

> Before deciding whether C++17 is closer to C99 or C11, you should also
> look at the features of C11 that were changes from C90, and are
> supported in the same way in C++17:
>
> ? Unicode characters and strings
> ? static assertions
> ? restricted character set support via digraphs
> ? the long long int type
> ? remove implicit int
> ? reliable integer division
> ? universal character names (\u and \U)
> ? // comments
> ? extended integer types
> ? remove implicit function declaration
> ? preprocessor arithmetic done in intmax_t/uintmax_t
> ? mixed declarations and code
> - declaration in first part of for().
> ? integer constant type rules
> ? integer promotion rules
> ? macros with a variable number of arguments
> ? trailing comma allowed in enum declaration
> ? idempotent type qualifiers
> ? empty macro arguments
> ? _Pragma preprocessing operator
> ? standard pragmas
> ? _ _func_ _ predefined identifier
> ? conversion of array to pointer not limited to lvalues
> ? relaxed constraints on aggregate and union initialization
> ? relaxed restrictions on portable header names
> ? return without expression not permitted in function that returns a
> value (and vice versa)

What makes you think I hadn't looked at these already?

> Disclaimer: that's a long list, and I didn't spend a lot of time to look
> into each item;  it might contain mistakes, or cases where there's
> differences between the C11 and C++17 feature that I didn't notice.
>
> Whether the items on the second list are more important than the items
> on the first list is a judgment call, and as such, inherently subjective.
> I have no interest in arguing with you about judgment calls.  I'm not
> even claiming that are more important - I didn't bother trying to
> make that
> judgment.  I'll limit myself to pointing out the objective fact that there
> are more items in the second list.

In graduate school I heard a very interesting statement about
universities making decisions regarding whether to award tenure:
"Some places count papers, some places weigh papers, and some
places read papers."

> The key point is that the C++ committee deliberately chose to change 1p2
> to refer to C11 rather than C90, implying that, in their judgment,
> there's enough features that were added in C99 and C11 that are also in
> C++17 to justify making that change.  You can disagree with their
> judgment on that matter - but its not an issue I'm willing to bother
> discussing.

I don't have any reason at this moment to think they are
considering the same question that I was considering.

>> Finally, let me point out Annex C, "Compatibility", in n4659.
>> Paragraph 1 of C.1 says
>>
>>     This subclause lists the differences between C++ and ISO C,
>>     by the chapters of this document.
>>
>> Despite that introduction, AFAICT no language features new to C99
>> or C11 are among those compared.  In fact one of the items listed
>> is implicit declaration of functions, which hasn't been part of
>> standard C for almost 20 years.  Also inline functions are not
>> listed.  So the C++ standard itself tacitly concedes the point
>> that, as far as the language goes, C++ is based on C90 and not on
>> C99 or C11.
>
> At best, it does so indirectly, and only after having
> explicitly stating that it is based on C11.

Yes, the tacit admission gives lie to the explicit statement.

Thread

C Construction Problem "F. Russell" <fr@random.info> - 2018-02-20 13:51 +0000
  Re: C Construction Problem bartc <bc@freeuk.com> - 2018-02-20 14:42 +0000
    Re: C Construction Problem "F. Russell" <fr@random.info> - 2018-02-20 15:06 +0000
      Re: C Construction Problem Manfred <noname@invalid.add> - 2018-02-20 18:07 +0100
  Re: C Construction Problem Jorgen Grahn <grahn+nntp@snipabacken.se> - 2018-02-20 14:54 +0000
  Re: C Construction Problem "James R. Kuyper" <jameskuyper@verizon.net> - 2018-02-20 10:06 -0500
    Re: C Construction Problem "F. Russell" <fr@random.info> - 2018-02-20 16:11 +0000
  Re: C Construction Problem Ben Bacarisse <ben.usenet@bsb.me.uk> - 2018-02-20 15:08 +0000
    Re: C Construction Problem "F. Russell" <fr@random.info> - 2018-02-20 16:22 +0000
      Re: C Construction Problem Ben Bacarisse <ben.usenet@bsb.me.uk> - 2018-02-20 17:03 +0000
        Re: C Construction Problem Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2018-02-20 09:23 -0800
        Re: C Construction Problem Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2018-02-20 11:11 -0700
        Re: C Construction Problem "F. Russell" <fr@random.info> - 2018-02-20 18:30 +0000
          Re: C Construction Problem Jorgen Grahn <grahn+nntp@snipabacken.se> - 2018-02-20 23:37 +0000
            Re: C Construction Problem "F. Russell" <fr@random.info> - 2018-02-21 00:45 +0000
              Re: C Construction Problem bartc <bc@freeuk.com> - 2018-02-21 01:46 +0000
                Re: C Construction Problem David Brown <david.brown@hesbynett.no> - 2018-02-21 08:49 +0100
                Re: C Construction Problem Jorgen Grahn <grahn+nntp@snipabacken.se> - 2018-02-21 09:29 +0000
                [OT] Re: C Construction Problem bartc <bc@freeuk.com> - 2018-02-21 11:24 +0000
                Re: [OT] Re: C Construction Problem Anton Shepelev <anton.txt@g{oogle}mail.com> - 2018-02-21 14:41 +0300
                Re: [OT] Re: C Construction Problem David Brown <david.brown@hesbynett.no> - 2018-02-21 15:10 +0100
                Re: [OT] Re: C Construction Problem Robert Wessel <robertwessel2@yahoo.com> - 2018-02-21 12:36 -0600
                Re: [OT] Re: C Construction Problem bartc <bc@freeuk.com> - 2018-02-21 21:04 +0000
                Re: [OT] Re: C Construction Problem Robert Wessel <robertwessel2@yahoo.com> - 2018-02-21 18:20 -0600
                Re: C Construction Problem Anton Shepelev <anton.txt@g{oogle}mail.com> - 2018-02-21 11:09 +0300
                Re: C Construction Problem Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2018-02-21 02:29 -0800
                Re: C Construction Problem "F. Russell" <fr@random.info> - 2018-02-21 11:32 +0000
                Re: C Construction Problem Geoff <geoff@invalid.invalid> - 2018-02-26 11:02 -0800
                Re: C Construction Problem David Brown <david.brown@hesbynett.no> - 2018-02-27 09:22 +0100
                Re: C Construction Problem Geoff <geoff@invalid.invalid> - 2018-02-27 11:18 -0800
                Re: C Construction Problem bartc <bc@freeuk.com> - 2018-02-27 19:51 +0000
                Re: C Construction Problem Robert Wessel <robertwessel2@yahoo.com> - 2018-02-28 01:54 -0600
                Re: C Construction Problem Robert Wessel <robertwessel2@yahoo.com> - 2018-02-28 01:43 -0600
                Re: C Construction Problem Geoff <geoff@invalid.invalid> - 2018-02-28 12:54 -0800
                Re: archive decompressor Noob <root@127.0.0.1> - 2018-03-04 12:34 +0100
              Re: C Construction Problem Anton Shepelev <anton.txt@g{oogle}mail.com> - 2018-02-21 11:04 +0300
                Re: C Construction Problem "F. Russell" <fr@random.info> - 2018-02-21 11:27 +0000
                Re: C Construction Problem Anton Shepelev <anton.txt@gmail.com> - 2018-02-28 22:59 +0300
                Re: C Construction Problem supercat@casperkitty.com - 2018-02-21 08:49 -0800
            Re: C Construction Problem Geoff <geoff@invalid.invalid> - 2018-02-26 11:08 -0800
              Re: C Construction Problem "F. Russell" <fr@random.info> - 2018-02-26 23:51 +0000
                Re: C Construction Problem Geoff <geoff@invalid.invalid> - 2018-02-27 11:24 -0800
          Re: C Construction Problem Tim Rentsch <txr@alumni.caltech.edu> - 2018-02-21 08:07 -0800
            Re: C Construction Problem fr314159@gmail.com - 2018-02-21 09:16 -0800
              Re: C Construction Problem Tim Rentsch <txr@alumni.caltech.edu> - 2018-02-21 21:26 -0800
            Re: C Construction Problem Keith Thompson <kst-u@mib.org> - 2018-02-21 09:43 -0800
              Re: C Construction Problem Tim Rentsch <txr@alumni.caltech.edu> - 2018-02-21 22:47 -0800
                Re: C Construction Problem Jorgen Grahn <grahn+nntp@snipabacken.se> - 2018-02-22 13:09 +0000
                Re: C Construction Problem Tim Rentsch <txr@alumni.caltech.edu> - 2018-02-24 13:37 -0800
                Re: C Construction Problem Keith Thompson <kst-u@mib.org> - 2018-02-22 10:50 -0800
                Re: C Construction Problem Tim Rentsch <txr@alumni.caltech.edu> - 2018-02-24 13:58 -0800
                Re: C Construction Problem Keith Thompson <kst-u@mib.org> - 2018-02-24 15:05 -0800
                Re: C Construction Problem Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2018-02-25 03:21 -0800
                Re: C Construction Problem bartc <bc@freeuk.com> - 2018-02-25 11:51 +0000
                Re: C Construction Problem Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2018-02-25 04:06 -0800
                Re: C Construction Problem bartc <bc@freeuk.com> - 2018-02-25 12:47 +0000
                Re: C Construction Problem "F. Russell" <fr@random.info> - 2018-02-25 13:20 +0000
                Re: C Construction Problem bartc <bc@freeuk.com> - 2018-02-25 17:46 +0000
                Re: C Construction Problem "F. Russell" <fr@random.info> - 2018-02-25 18:58 +0000
                Re: C Construction Problem bartc <bc@freeuk.com> - 2018-02-25 20:01 +0000
                Re: C Construction Problem bartc <bc@freeuk.com> - 2018-02-25 20:25 +0000
                Re: C Construction Problem Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2018-02-26 02:49 -0800
                Re: C Construction Problem Ben Bacarisse <ben.usenet@bsb.me.uk> - 2018-02-25 20:02 +0000
                Re: C Construction Problem Keith Thompson <kst-u@mib.org> - 2018-02-25 15:13 -0800
                Re: C Construction Problem Robert Wessel <robertwessel2@yahoo.com> - 2018-02-25 11:50 -0600
                Re: C Construction Problem Ian Collins <ian-news@hotmail.com> - 2018-02-26 07:38 +1300
                Re: C Construction Problem Keith Thompson <kst-u@mib.org> - 2018-02-25 15:15 -0800
                Re: C Construction Problem Tim Rentsch <txr@alumni.caltech.edu> - 2018-02-26 22:02 -0800
                Re: C Construction Problem jameskuyper@verizon.net - 2018-02-27 06:32 -0800
                Re: C Construction Problem GOTHIER Nathan <nathan.gothier@gmail.com> - 2018-02-27 16:56 +0100
                Re: C Construction Problem jameskuyper@verizon.net - 2018-02-27 08:27 -0800
                Re: C Construction Problem GOTHIER Nathan <nathan.gothier@gmail.com> - 2018-02-27 18:02 +0100
                Re: C Construction Problem jameskuyper@verizon.net - 2018-02-27 10:23 -0800
                Re: C Construction Problem Tim Rentsch <txr@alumni.caltech.edu> - 2018-03-03 01:09 -0800
                Re: C Construction Problem David Brown <david.brown@hesbynett.no> - 2018-02-28 10:37 +0100
                Re: C Construction Problem Tim Rentsch <txr@alumni.caltech.edu> - 2018-03-03 01:29 -0800
                Re: C Construction Problem Steven Petruzzellis <frelwizzen@gmail.com> - 2018-03-03 02:00 -0800
                Re: C Construction Problem Keith Thompson <kst-u@mib.org> - 2018-02-27 08:46 -0800
                Re: C Construction Problem jameskuyper@verizon.net - 2018-02-27 09:15 -0800
                Re: C Construction Problem Tim Rentsch <txr@alumni.caltech.edu> - 2018-03-03 02:08 -0800
                Re: C Construction Problem Steven Petruzzellis <frelwizzen@gmail.com> - 2018-03-03 02:31 -0800
                Re: C Construction Problem Ian Collins <ian-news@hotmail.com> - 2018-03-04 10:34 +1300
                Re: C Construction Problem Tim Rentsch <txr@alumni.caltech.edu> - 2018-03-19 10:27 -0700
                Re: C Construction Problem jameskuyper@verizon.net - 2018-03-03 21:35 -0800
                Re: C Construction Problem Tim Rentsch <txr@alumni.caltech.edu> - 2018-03-17 10:29 -0700
                Re: C Construction Problem Steven Petruzzellis <frelwizzen@gmail.com> - 2018-03-18 08:14 -0700
                Re: C Construction Problem David Brown <david.brown@hesbynett.no> - 2018-02-25 21:49 +0100
                Re: C Construction Problem Keith Thompson <kst-u@mib.org> - 2018-02-25 15:09 -0800
                Re: C Construction Problem gazelle@shell.xmission.com (Kenny McCormack) - 2018-02-26 13:46 +0000
                Re: C Construction Problem David Brown <david.brown@hesbynett.no> - 2018-02-26 14:57 +0100
                Re: C Construction Problem Tim Rentsch <txr@alumni.caltech.edu> - 2018-02-26 22:14 -0800
            Re: C Construction Problem "F. Russell" <fr@random.info> - 2018-02-22 00:11 +0000
              Re: C Construction Problem Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2018-02-21 17:27 -0700
    Re: C Construction Problem Keith Thompson <kst-u@mib.org> - 2018-02-20 09:30 -0800
      Re: C Construction Problem Ben Bacarisse <ben.usenet@bsb.me.uk> - 2018-02-21 00:23 +0000
  Re: C Construction Problem Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2018-02-20 09:11 -0700
    Re: C Construction Problem "F. Russell" <fr@random.info> - 2018-02-20 16:38 +0000
      Re: C Construction Problem bartc <bc@freeuk.com> - 2018-02-20 17:07 +0000
      Re: C Construction Problem John Bode <jfbode1029@gmail.com> - 2018-02-20 09:09 -0800
      Re: C Construction Problem "James R. Kuyper" <jameskuyper@verizon.net> - 2018-02-20 12:18 -0500
        Re: C Construction Problem Keith Thompson <kst-u@mib.org> - 2018-02-20 09:38 -0800
      Re: C Construction Problem Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2018-02-20 11:08 -0700
      Re: C Construction Problem Gordon Burditt <gordon@hammy.burditt.org> - 2018-02-20 21:47 -0600
        Re: C Construction Problem Keith Thompson <kst-u@mib.org> - 2018-02-21 09:36 -0800
          Re: C Construction Problem Geoff <geoff@invalid.invalid> - 2018-02-26 11:21 -0800

csiph-web