Re: removing constness of a true const

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From	Ian Collins <ian-news@hotmail.com>
Newsgroups	comp.lang.c++
Subject	Re: removing constness of a true const
Date	Sat, 16 Jul 2011 08:36:18 +1200
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On 07/16/11 04:04 AM, Balog Pal wrote:
> "Victor Bazarov"<v.bazarov@comcast.invalid>
>>> const std::pair<int, int>  foo = std::make_pair(1,2);
>>>
>>> is any less const than two separate ints? Or that overwriting them is
>>> less UB?
>>>
>>> I'd be very disappointed if today's compilers would not put that pair in
>>> the 'const' segment and fiddling with it would not cause a crash.
>>
>> Any data initializing which requires code to be executed at runtime cannot
>> be put in "the 'const' segment" - the segment would not be const, would
>> it?
>
> Why should it be initialized "at runtime"?  Unless you have volatiles
> involved, what is pretty rare, the standard mandates that initialisation
> happened before you use. Not telling how much before. It can be done at
> compile time, if the compiler can guess the result. Like in the above case.

Maybe it could, but do you know a case where it is?  The two compilers I 
tried (Sun CC and g++) build the object in a static constructor.

Oh the joys of UB....

-- 
Ian Collins

Thread

removing constness of a true const siddhu <siddharth.sng@gmail.com> - 2011-07-14 08:07 -0700
  Re: removing constness of a true const Victor Bazarov <v.bazarov@comcast.invalid> - 2011-07-14 11:55 -0400
    Re: removing constness of a true const siddhu <siddharth.sng@gmail.com> - 2011-07-14 09:25 -0700
      Re: removing constness of a true const Victor Bazarov <v.bazarov@comcast.invalid> - 2011-07-14 16:18 -0400
        Re: removing constness of a true const "Balog Pal" <pasa@lib.hu> - 2011-07-15 01:18 +0200
          Re: removing constness of a true const Victor Bazarov <v.bazarov@comcast.invalid> - 2011-07-15 08:17 -0400
            Re: removing constness of a true const "Balog Pal" <pasa@lib.hu> - 2011-07-15 18:04 +0200
              Re: removing constness of a true const Ian Collins <ian-news@hotmail.com> - 2011-07-16 08:36 +1200
                Re: removing constness of a true const "Balog Pal" <pasa@lib.hu> - 2011-07-16 02:00 +0200
            Re: removing constness of a true const Paavo Helde <myfirstname@osa.pri.ee> - 2011-07-15 16:08 -0500
              Re: removing constness of a true const Ian Collins <ian-news@hotmail.com> - 2011-07-16 09:30 +1200
  Re: removing constness of a true const "Balog Pal" <pasa@lib.hu> - 2011-07-14 19:05 +0200
    Re: removing constness of a true const siddhu <siddharth.sng@gmail.com> - 2011-07-14 12:05 -0700
      Re: removing constness of a true const "Bo Persson" <bop@gmb.dk> - 2011-07-14 23:33 +0200
        Re: removing constness of a true const Victor Bazarov <v.bazarov@comcast.invalid> - 2011-07-14 17:46 -0400
          Re: removing constness of a true const "Bo Persson" <bop@gmb.dk> - 2011-07-16 08:32 +0200
  Re: removing constness of a true const "Johannes Schaub (litb)" <schaub.johannes@googlemail.com> - 2011-07-15 15:02 +0200
    Re: removing constness of a true const Victor Bazarov <v.bazarov@comcast.invalid> - 2011-07-15 09:54 -0400

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