Re: [boost] New Library Proposal: dual_state

From: David Abrahams (dave_at_[hidden])
Date: 2005-07-09 22:41:33

"Jost, Andrew" <Andrew_Jost_at_[hidden]> writes:

> This is my first post to the Boost distribution list, so please feel
> free to speak up if you find any part of this message to be outside the
> normal decorum.
>  
> I am curious if there is support for what I'm calling a "dual_state"
> template class.  Anyone familiar with Perl will instantly recognize the
> parallel.  The idea is to attach a "statedness" value to arbitrary
> objects, allowing us to consider them defined or undefined.  Newly
> constructed dual_state objects are undefined.  For example,

Have you looked at Boost.Optional?
http://www.boost.org/libs/optional/doc/optional.html

-- 
Dave Abrahams
Boost Consulting
www.boost-consulting.com