Re: [Boost-users] [STL] An question about list::iterator

From: LoadCom (LoadCom_at_[hidden])
Date: 2007-11-06 00:49:30

Hi, Krishnamurthy,

Perhaps the tribool is a good counterpart of type bool,
the underminent condition of a tribool for bool type is just
as an uninitialized iterator, it_NULL, for an iterator type
I'm looking for.

Thanks.

Max

Hi,

On 11/5/07, LoadCom <LoadCom_at_[hidden]> wrote:
> Or, in other words, I want to test if an iterator
> itself doesn't point to any object - that is different from
> the begin() or end() of a list.

>From my little understanding of the rationale behind such a behavior,
following is my take on it.

1. The iterator is a pattern to fetch the content/s of a container
2. Hence, it really points to a location. It could either be the first
entry (begin), something till the last (including the last element) or
beyond to signify the end of the container

I do feel it would be right to have an iterator pointing to nowhere.
Maybe an uninitialized state would make sense but that would be like
have a similar state for a boolean. The boolean can either be true or
false, you do not have a third state to say that it was not
initialized. Maybe, the boost::tribool is the outcome of such a
requirement, I am just guessing though.

-dky

-- 
Dhruva Krishnamurthy
Contents reflect my personal views only!
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