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Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour.

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"Leigh Johnston" <leigh@i42.co.uk> wrote in message 
news:opqdnTXA5ZgKLovSnZ2dnUVZ8mGdnZ2d@giganews.com...
> On 18/01/2012 10:38, Paul <pchrist wrote:
>> "Paul or@yahoo.co.uk>"<pchrist<nospam>  wrote in message
>> news:jf4b7m$28nh$1@adenine.netfront.net...
>>>
>>> "Leigh Johnston"<leigh@i42.co.uk>  wrote in message
>>> news:I_Cdne08KLk9OYjSnZ2dnUVZ8n6dnZ2d@giganews.com...
>>>> On 17/01/2012 16:35, Paul<pchrist wrote:
>>>>> "gwowen"<gwowen@gmail.com>   wrote in message
>>>>> news:c80e1e14-f27a-4b7a-946f-c91d8ddf6832@e8g2000yqd.googlegroups.com...
>>>>> On Jan 17, 2:52 pm, Leigh Johnston<le...@i42.co.uk>   wrote:
>>>>>> I agree; this is a rather esoteric corner of C++ we are dealing with. 
>>>>>> I
>>>>>> personally have never had the need in my code to call a pure virtual
>>>>>> function from a ctor but I nevertheless thought it interesting to 
>>>>>> post
>>>>>> about it in this forum.
>>>>>
>>>>> --Don't get me wrong - I'm not criticising you for doing so. I've
>>>>> --learned that you can define pure virtual functions (although you
>>>>> --probably shouldn't ;) ), so I've gained something from your bringing
>>>>> --it up.
>>>>>
>>>>> I think its a handy feature for supplying some default functionality.
>>>>> If it were automatic(invoked during construction of abstract class)
>>>>> then it
>>>>> couldn't be overridden in a concrete class and perhaps this is why the
>>>>> standard specifiies it as UB.
>>>>
>>>> You are wrong.  Why are you wrong?  Because a) you don't know how 
>>>> vtables
>>>> work and b) you don't understand that the dynamic type of an object
>>>> changes as it moves from base class ctor to derived class ctor.
>>>>
>>> What exactly am I wrong about here?
>>>
>> So Im not wrong then and you are actually the one who is wrong, as 
>> usual..
>
> You are wrong.  Why are you wrong?  Because a) you don't know how vtables 
> work and b) you don't understand that the dynamic type of an object 
> changes as it moves from base class ctor to derived class ctor.
>
And you are a faggot

*shrugg*




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Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. Leigh Johnston <leigh@i42.co.uk> - 2012-01-14 23:06 +0000
  Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. Goran <goran.pusic@gmail.com> - 2012-01-14 22:21 -0800
  Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. "MikeWhy" <boat042-nospam@yahoo.com> - 2012-01-15 02:25 -0600
    Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. Leigh Johnston <leigh@i42.co.uk> - 2012-01-15 14:07 +0000
      Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. "MikeWhy" <boat042-nospam@yahoo.com> - 2012-01-15 13:13 -0600
  Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. "Alf P. Steinbach" <alf.p.steinbach+usenet@gmail.com> - 2012-01-15 09:29 +0100
    Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. Leigh Johnston <leigh@i42.co.uk> - 2012-01-15 14:16 +0000
      Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. "Alf P. Steinbach" <alf.p.steinbach+usenet@gmail.com> - 2012-01-15 15:25 +0100
        Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. Leigh Johnston <leigh@i42.co.uk> - 2012-01-15 14:30 +0000
  Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. gwowen <gwowen@gmail.com> - 2012-01-16 01:57 -0800
    Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. "Alf P. Steinbach" <alf.p.steinbach+usenet@gmail.com> - 2012-01-16 11:28 +0100
      Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. Leigh Johnston <leigh@i42.co.uk> - 2012-01-16 11:29 +0000
      Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. gwowen <gwowen@gmail.com> - 2012-01-16 03:21 -0800
  Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. "Paul" <pchrist<nospam>or@yahoo.co.uk> - 2012-01-16 12:04 +0000
    Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. Leigh Johnston <leigh@i42.co.uk> - 2012-01-16 12:52 +0000
      Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. "Paul" <pchrist<nospam>or@yahoo.co.uk> - 2012-01-16 14:14 +0000
        Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. Leigh Johnston <leigh@i42.co.uk> - 2012-01-16 14:26 +0000
          Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. "Paul" <pchrist<nospam>or@yahoo.co.uk> - 2012-01-16 16:14 +0000
            Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. Leigh Johnston <leigh@i42.co.uk> - 2012-01-16 16:37 +0000
              Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. "Paul" <pchrist<nospam>or@yahoo.co.uk> - 2012-01-16 18:02 +0000
                Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. Leigh Johnston <leigh@i42.co.uk> - 2012-01-16 18:22 +0000
                Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. "Paul" <pchrist<nospam>or@yahoo.co.uk> - 2012-01-16 19:15 +0000
                Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. Leigh Johnston <leigh@i42.co.uk> - 2012-01-16 20:34 +0000
                Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. Leigh Johnston <leigh@i42.co.uk> - 2012-01-16 20:41 +0000
                Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. "Paul" <pchrist<nospam>or@yahoo.co.uk> - 2012-01-16 20:49 +0000
                Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. Leigh Johnston <leigh@i42.co.uk> - 2012-01-16 21:08 +0000
                Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. Leigh Johnston <leigh@i42.co.uk> - 2012-01-16 21:11 +0000
                Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. "Paul" <pchrist<nospam>or@yahoo.co.uk> - 2012-01-16 23:18 +0000
                Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. Leigh Johnston <leigh@i42.co.uk> - 2012-01-16 23:39 +0000
                Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. "Paul" <pchrist<nospam>or@yahoo.co.uk> - 2012-01-16 23:48 +0000
                Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. Leigh Johnston <leigh@i42.co.uk> - 2012-01-16 23:57 +0000
                Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. "Paul" <pchrist<nospam>or@yahoo.co.uk> - 2012-01-17 12:24 +0000
                Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. Leigh Johnston <leigh@i42.co.uk> - 2012-01-17 14:11 +0000
                Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. gwowen <gwowen@gmail.com> - 2012-01-17 06:43 -0800
                Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. Leigh Johnston <leigh@i42.co.uk> - 2012-01-17 14:52 +0000
                Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. gwowen <gwowen@gmail.com> - 2012-01-17 07:22 -0800
                Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. "Paul" <pchrist<nospam>or@yahoo.co.uk> - 2012-01-17 16:35 +0000
                Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. Leigh Johnston <leigh@i42.co.uk> - 2012-01-17 16:40 +0000
                Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. "Paul" <pchrist<nospam>or@yahoo.co.uk> - 2012-01-17 17:30 +0000
                Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. "Paul" <pchrist<nospam>or@yahoo.co.uk> - 2012-01-18 10:38 +0000
                Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. Leigh Johnston <leigh@i42.co.uk> - 2012-01-18 11:57 +0000
                Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. "Paul" <pchrist<nospam>or@yahoo.co.uk> - 2012-01-18 12:49 +0000
                Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. gwowen <gwowen@gmail.com> - 2012-01-17 08:59 -0800
                Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. Leigh Johnston <leigh@i42.co.uk> - 2012-01-17 17:03 +0000
                Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. "MikeWhy" <boat042-nospam@yahoo.com> - 2012-01-17 11:34 -0600
                Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. "MikeWhy" <boat042-nospam@yahoo.com> - 2012-01-17 12:14 -0600
                Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. Gareth Owen <gwowen@gmail.com> - 2012-01-18 06:37 +0000
                Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. "MikeWhy" <boat042-nospam@yahoo.com> - 2012-01-18 13:08 -0600
                Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. "MikeWhy" <boat042-nospam@yahoo.com> - 2012-01-18 13:14 -0600
                Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. "Paul" <pchrist<nospam>or@yahoo.co.uk> - 2012-01-17 15:50 +0000
                Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. Leigh Johnston <leigh@i42.co.uk> - 2012-01-17 15:59 +0000
                Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. "Paul" <pchrist<nospam>or@yahoo.co.uk> - 2012-01-17 16:09 +0000
          Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. jgk@panix.com (Joe keane) - 2012-01-17 16:13 +0000
            Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. scott@slp53.sl.home (Scott Lurndal) - 2012-01-18 18:11 +0000
        Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. gwowen <gwowen@gmail.com> - 2012-01-16 06:34 -0800
  Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. Gil <vnicula@gmail.com> - 2012-01-16 20:55 -0800
  Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. Leigh Johnston <leigh@i42.co.uk> - 2012-01-17 17:58 +0000
    Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. scott@slp53.sl.home (Scott Lurndal) - 2012-01-18 18:12 +0000
      Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. Leigh Johnston <leigh@i42.co.uk> - 2012-01-18 19:00 +0000
        Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. "Paul" <pchrist<nospam>or@yahoo.co.uk> - 2012-01-18 22:00 +0000
      Re: Rationale for base class pure virtual function call from ctor/dtor being undefined behaviour. Gareth Owen <gwowen@gmail.com> - 2012-01-19 06:22 +0000

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