Re: [boost] interest in pair projection iterators?

From: David Abrahams (dave_at_[hidden])
Date: 2005-10-12 23:23:09

Lewis Hyatt <lhyatt_at_[hidden]> writes:

> The idea is to define a template class,
>
> template<typename Iterator> class first_iterator_t {
> 	Iterator pair_iter;
> public:
> 	first_iterator_t(Iterator const&);
> 	/*...*/
> };
>
> which overloads operator*() and operator->() to access the element named 
> "first" of the object returned by Iterator::operator*(). (With something 
> analagous for second_iterator_t.) A function named first_iterator() 
> provides a convenient creation function a-la std::make_pair().

Sounds like a job for transform_iterator.

http://www.boost.org/libs/iterator/doc/transform_iterator.html

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