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Re: lvalues from the ternary op

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From Keith Thompson <kst-u@mib.org>
Newsgroups comp.lang.c
Subject Re: lvalues from the ternary op
Date Wed, 04 Jan 2017 15:21:46 -0800
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supercat@casperkitty.com writes:
> On Wednesday, January 4, 2017 at 3:48:34 PM UTC-6, Keith Thompson wrote:
>> For example, this:
>> 
>>     int x;
>>     double y;
>>     (condition ? x : y) = 42;
>> 
>> would be difficult to implement sensibly.  Taking the address of a
>> ternary expression would be even more difficult.  (C++ already does
>> this; I haven't checked the standard's wording.)
>
> The Standard already includes type resolution rules for condition?p:q where
> p and q are pointers.  If the result of the conditional expression is used
> as an object, is there any reason the type resolution rules for
> *(condition ? &x : &y) couldn't be used for (condition ? x : y), but with
> the proviso that if the address of the expression isn't taken, x and y need
> not be regarded as having had their addresses taken by the expression, would
> not be adequate?

No reason I can think of (but I'd probably phrase the proviso
differently).  Of course (condition ? x : y) in the example above still
wouldn't be an lvalue.

-- 
Keith Thompson (The_Other_Keith) kst-u@mib.org  <http://www.ghoti.net/~kst>
Working, but not speaking, for JetHead Development, Inc.
"We must do something.  This is something.  Therefore, we must do this."
    -- Antony Jay and Jonathan Lynn, "Yes Minister"

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Thread

Re: lvalues from the ternary op Manfred <noname@invalid.add> - 2017-01-04 19:46 +0100
  Re: lvalues from the ternary op supercat@casperkitty.com - 2017-01-04 11:08 -0800
  Re: lvalues from the ternary op Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-01-04 21:10 +0000
    Re: lvalues from the ternary op Keith Thompson <kst-u@mib.org> - 2017-01-04 13:48 -0800
      Re: lvalues from the ternary op Ian Collins <ian-news@hotmail.com> - 2017-01-05 11:07 +1300
        Re: lvalues from the ternary op Keith Thompson <kst-u@mib.org> - 2017-01-04 14:20 -0800
      Re: lvalues from the ternary op supercat@casperkitty.com - 2017-01-04 14:41 -0800
        Re: lvalues from the ternary op Keith Thompson <kst-u@mib.org> - 2017-01-04 15:21 -0800
          Re: lvalues from the ternary op supercat@casperkitty.com - 2017-01-04 15:52 -0800
            Re: lvalues from the ternary op Keith Thompson <kst-u@mib.org> - 2017-01-04 16:37 -0800
            Re: lvalues from the ternary op Keith Thompson <kst-u@mib.org> - 2017-01-04 18:31 -0800
              Re: lvalues from the ternary op Tim Rentsch <txr@alumni.caltech.edu> - 2017-01-13 17:26 -0800
                Re: lvalues from the ternary op Keith Thompson <kst-u@mib.org> - 2017-01-13 17:49 -0800
                Re: lvalues from the ternary op Tim Rentsch <txr@alumni.caltech.edu> - 2017-01-15 22:53 -0800
    Re: lvalues from the ternary op Tim Rentsch <txr@alumni.caltech.edu> - 2017-01-13 17:08 -0800
      Re: lvalues from the ternary op Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-01-14 02:15 +0000
        Re: lvalues from the ternary op Tim Rentsch <txr@alumni.caltech.edu> - 2017-01-15 22:51 -0800
      Re: lvalues from the ternary op luser droog <luser.droog@gmail.com> - 2017-01-16 23:09 -0800
        Re: lvalues from the ternary op Manfred <noname@invalid.add> - 2017-01-18 14:51 +0100
          Re: lvalues from the ternary op Keith Thompson <kst-u@mib.org> - 2017-01-18 09:59 -0800
            Re: lvalues from the ternary op Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2017-01-18 13:12 -0500
            Re: lvalues from the ternary op supercat@casperkitty.com - 2017-01-18 12:11 -0800
              Re: lvalues from the ternary op Keith Thompson <kst-u@mib.org> - 2017-01-18 12:45 -0800
                Re: lvalues from the ternary op supercat@casperkitty.com - 2017-01-18 14:07 -0800
                Re: lvalues from the ternary op Keith Thompson <kst-u@mib.org> - 2017-01-18 14:40 -0800
                Re: lvalues from the ternary op supercat@casperkitty.com - 2017-01-18 16:10 -0800
                Re: lvalues from the ternary op Keith Thompson <kst-u@mib.org> - 2017-01-18 18:08 -0800
                Re: lvalues from the ternary op supercat@casperkitty.com - 2017-01-19 06:44 -0800
                Re: lvalues from the ternary op Keith Thompson <kst-u@mib.org> - 2017-01-19 08:40 -0800
                Re: lvalues from the ternary op supercat@casperkitty.com - 2017-01-19 12:32 -0800
                Re: lvalues from the ternary op supercat@casperkitty.com - 2017-01-20 06:01 -0800
                Re: lvalues from the ternary op Keith Thompson <kst-u@mib.org> - 2017-01-20 08:15 -0800
                Re: lvalues from the ternary op supercat@casperkitty.com - 2017-01-20 10:51 -0800
                Re: lvalues from the ternary op Keith Thompson <kst-u@mib.org> - 2017-01-20 11:32 -0800
                Re: lvalues from the ternary op supercat@casperkitty.com - 2017-01-20 13:41 -0800
                Re: lvalues from the ternary op supercat@casperkitty.com - 2017-01-23 07:04 -0800
                Re: lvalues from the ternary op Ike Naar <ike@iceland.freeshell.org> - 2017-01-23 17:59 +0000
                Re: lvalues from the ternary op supercat@casperkitty.com - 2017-01-23 10:57 -0800
                Re: lvalues from the ternary op Tim Rentsch <txr@alumni.caltech.edu> - 2017-01-31 08:45 -0800
                Re: lvalues from the ternary op Keith Thompson <kst-u@mib.org> - 2017-01-31 09:13 -0800
                Re: lvalues from the ternary op supercat@casperkitty.com - 2017-01-31 10:17 -0800
                Re: lvalues from the ternary op Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-02-01 01:51 +0000
                Re: lvalues from the ternary op supercat@casperkitty.com - 2017-02-01 14:24 -0800
                Re: lvalues from the ternary op Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-02-02 03:07 +0000
                Re: lvalues from the ternary op Tim Rentsch <txr@alumni.caltech.edu> - 2017-02-04 04:43 -0800
                Re: lvalues from the ternary op supercat@casperkitty.com - 2017-02-04 08:01 -0800
                Re: lvalues from the ternary op Tim Rentsch <txr@alumni.caltech.edu> - 2017-02-09 09:06 -0800
                Re: lvalues from the ternary op supercat@casperkitty.com - 2017-02-09 11:56 -0800
                Re: lvalues from the ternary op Tim Rentsch <txr@alumni.caltech.edu> - 2017-02-12 10:29 -0800
                Re: lvalues from the ternary op supercat@casperkitty.com - 2017-02-12 13:43 -0800
                Re: lvalues from the ternary op Tim Rentsch <txr@alumni.caltech.edu> - 2017-02-19 21:44 -0800
                Re: lvalues from the ternary op supercat@casperkitty.com - 2017-02-20 08:15 -0800
                Re: lvalues from the ternary op Tim Rentsch <txr@alumni.caltech.edu> - 2017-02-24 07:58 -0800
                Re: lvalues from the ternary op supercat@casperkitty.com - 2017-02-24 10:00 -0800
                Re: lvalues from the ternary op scott@slp53.sl.home (Scott Lurndal) - 2017-02-24 18:58 +0000
                Re: lvalues from the ternary op supercat@casperkitty.com - 2017-02-24 13:03 -0800
                Re: lvalues from the ternary op Keith Thompson <kst-u@mib.org> - 2017-02-24 14:11 -0800
                Re: lvalues from the ternary op Keith Thompson <kst-u@mib.org> - 2017-02-24 12:42 -0800
                Re: lvalues from the ternary op Keith Thompson <kst-u@mib.org> - 2017-02-24 13:49 -0800
                Re: lvalues from the ternary op supercat@casperkitty.com - 2017-02-24 13:58 -0800
                Re: lvalues from the ternary op Keith Thompson <kst-u@mib.org> - 2017-02-24 14:56 -0800
                Re: lvalues from the ternary op supercat <flatfinger@casperkitty.com> - 2017-02-25 14:00 -0800
                Re: lvalues from the ternary op Tim Rentsch <txr@alumni.caltech.edu> - 2017-02-25 09:23 -0800
                Re: lvalues from the ternary op Tim Rentsch <txr@alumni.caltech.edu> - 2017-02-25 09:43 -0800
                Re: lvalues from the ternary op Kelsey Bjarnason <kbjarnason@gmail.com> - 2017-02-01 22:47 -0800
                Re: lvalues from the ternary op supercat@casperkitty.com - 2017-02-02 10:12 -0800
                Re: lvalues from the ternary op Tim Rentsch <txr@alumni.caltech.edu> - 2017-02-04 07:51 -0800
                Re: lvalues from the ternary op supercat@casperkitty.com - 2017-02-04 08:18 -0800
                Re: lvalues from the ternary op Tim Rentsch <txr@alumni.caltech.edu> - 2017-02-09 08:58 -0800
                Re: lvalues from the ternary op Tim Rentsch <txr@alumni.caltech.edu> - 2017-02-04 04:00 -0800
                Re: lvalues from the ternary op Kelsey Bjarnason <kbjarnason@gmail.com> - 2017-02-04 09:35 -0800
                Re: lvalues from the ternary op Tim Rentsch <txr@alumni.caltech.edu> - 2017-02-04 09:35 -0800
                Re: lvalues from the ternary op Robert Wessel <robertwessel2@yahoo.com> - 2017-01-31 13:36 -0600
                Re: lvalues from the ternary op supercat@casperkitty.com - 2017-01-31 12:23 -0800
                Re: lvalues from the ternary op Tim Rentsch <txr@alumni.caltech.edu> - 2017-02-01 13:48 -0800
                Re: lvalues from the ternary op Tim Rentsch <txr@alumni.caltech.edu> - 2017-01-31 08:53 -0800
            Re: lvalues from the ternary op Manfred <noname@invalid.add> - 2017-01-19 14:10 +0100
        Re: lvalues from the ternary op Tim Rentsch <txr@alumni.caltech.edu> - 2017-01-30 12:05 -0800

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