Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.c++ > #7823

Re: removing constness of a true const

Show all headers | View raw

On 7/14/2011 5:33 PM, Bo Persson wrote:
> siddhu wrote:
>> On Jul 14, 1:05 pm, "Balog Pal"<p...@lib.hu>  wrote:
>>> "siddhu"<siddharth....@gmail.com>
>>>
>>>> I guess removing constness of a true const( I guess it is also
>>>> called bitwise const ) using const_cast is undefined behavior.
>>>> Can you please give an example of a true const and may be a
>>>> sample code which exhibits undefined behavior by removing
>>>> constness of a true const.
>>>
>>> Removing constness is well defined. But actually modifying
>>> non-mutable member of a const object is UB. By any means,
>>> including the use of pointer/ref from const_cast.
>>
>> Thanks Balog!
>> Does that mean removing constness of 'this' in const member function
>> is an UB?
>
> It is if the object is really const.
>
> Suppose the data is stored in a ROM. What happens when you try to
> change it?

I see two concepts here, removing of 'const' and changing.  I don't 
think that the former is the same as the latter, or is it?

V
-- 
I do not respond to top-posted replies, please don't ask

Back to comp.lang.c++ | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

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

csiph-web