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Re: mutable vs const_cast, which is better to modify field from const function?

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On 2011-7-9 14:19, Qi wrote:
> It's not rare to lazy initialize member field in getter functions which
> are const function.

Hi all,

Thanks you all so much for pointing out the Undefined Behavior to
modify a const object.
I didn't know that before.

So I will definitely keep away from const_cast<>(this) and go
mutable way.

For anyone has interesting in learning UB on modifying const object,
here is the quote from the standard 03,

7.1.5.1 p4,
Except that any class member declared mutable (7.1.1) can be modified,
any attempt to modify a const object during its lifetime (3.8)
results in undefined behavior.


-- 
WQ

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mutable vs const_cast, which is better to modify field from const function? Qi <no@no.com> - 2011-07-09 14:19 +0800
  Re: mutable vs const_cast, which is better to modify field from const function? Narinder <narinder.claire@gmail.com> - 2011-07-09 00:20 -0700
    Re: mutable vs const_cast, which is better to modify field from const function? Qi <no@no.com> - 2011-07-09 15:50 +0800
      Re: mutable vs const_cast, which is better to modify field from const function? Narinder <narinder.claire@gmail.com> - 2011-07-09 01:36 -0700
  Re: mutable vs const_cast, which is better to modify field from const   function? Ian Collins <ian-news@hotmail.com> - 2011-07-09 19:28 +1200
    Re: mutable vs const_cast, which is better to modify field from const   function? Qi <no@no.com> - 2011-07-09 15:56 +0800
      Re: mutable vs const_cast, which is better to modify field from const     function? Ian Collins <ian-news@hotmail.com> - 2011-07-09 20:04 +1200
      Re: mutable vs const_cast, which is better to modify field from const function? Narinder <narinder.claire@gmail.com> - 2011-07-12 15:41 -0700
  Re: mutable vs const_cast, which is better to modify field from const function? SG <s.gesemann@gmail.com> - 2011-07-09 01:25 -0700
    Re: mutable vs const_cast, which is better to modify field from const function? Werner Erasmus <werasm@gmail.com> - 2011-07-10 22:25 +0200
      Re: mutable vs const_cast, which is better to modify field from const function? Qi <no@no.no> - 2011-07-11 09:54 +0800
        Re: mutable vs const_cast, which is better to modify field from const function? Werner Erasmus <werasm@gmail.com> - 2011-07-11 09:08 +0200
  Re: mutable vs const_cast, which is better to modify field from const function? Paavo Helde <myfirstname@osa.pri.ee> - 2011-07-09 03:31 -0500
  Re: mutable vs const_cast, which is better to modify field from const function? "Balog Pal" <pasa@lib.hu> - 2011-07-09 10:47 +0200
  Re: mutable vs const_cast, which is better to modify field from const function? Qi <no@no.com> - 2011-07-09 16:54 +0800

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