Re: [boost] Re: Re: Re: [pointer container] copyability

From: Peter Dimov (pdimov_at_[hidden])
Date: 2005-04-26 17:52:00

Thorsten Ottosen wrote:
> "Peter Dimov" <pdimov_at_[hidden]> wrote in message
> news:094101c54aaa$f55dfb40$6401a8c0_at_pdimov2...
>> Thorsten Ottosen wrote:
>>> "Peter Dimov" <pdimov_at_[hidden]> wrote in message
>>> news:090601c54aa7$0c9d5ac0$6401a8c0_at_pdimov2...
>>>> Thorsten Ottosen wrote:
>>>>> They [copying and cloning] are conceptually different, just like
>>>>> copying and moving are different and just like value-based
>>>>> programming is different from OO-programming.
>>>>
>>>> Why are copying and cloning conceptually different and why is
>>>> value-based programming different from OO programming?
>>>
>>> is this a joke?
>>
>> No.
>
> I think you have to explain why they are not different then.

The burden of proof lies usually with the person making the statement. ;-)

The reference semantics vs value semantics axis is orthogonal to OO, in my 
opinion. The fact that in C++ you can't (efficiently) have polymorphism with 
value semantics doesn't mean that copying a value and copying a polymorphic 
object are conceptually or fundamentally different.

A cloning pointer is a very good approximation of a polymorphic value. I 
don't see why you consider it conceptually different from a value.