Re: [Boost-users] A forward iterator need not be default-constructible

Subject: Re: [Boost-users] A forward iterator need not be default-constructible
From: Krzysztof Żelechowski (giecrilj_at_[hidden])
Date: 2011-10-04 12:59:46

Dave Abrahams wrote:

> 
> on Mon Oct 03 2011, Krzysztof Żelechowski <giecrilj-AT-stegny.2a.pl>
> wrote:
> 
>> Dave Abrahams wrote:
>>
>>> 
>>> on Sun Oct 02 2011, Andrew Sutton <asutton.list-AT-gmail.com> wrote:
>>> 
>>>> I would take that to mean that singularity is independent of type.
>>> 
>>> Although many types have singular values with respect to certain
>>> operations (NULL is singular with respect to pointer dereference),
>>> 
>>> - Not every type has singular values
>>> - Some types have multiple singular values
>>> - In general, one type's singular values are distinct from another
>>>   type's singular values
>>> 
>>> I don't know what you and Chris mean by "independent of type," but to me
>>> this sounds like singularity is highly dependent on type.
>>
>> It means iterators of the same type can be singular but need not, whereas
>> all (valid) iterators of the same type either must support random access
>> operations or must not, depending on the type in question.
> 
> Not so, and I can think of a counterexample, but I'm getting tired of
> arguing about it.  I don't think this is really relevant to the
> discussion in the end, is it?
> 

I understand that you may be tired of my questions, and I appreciate your 
answering them :-)  Thank you very much anyway.

Chris