[boost] Re: Date iterators in Boost Date-Time

From: Chris Trengove (trengove_at_[hidden])
Date: 2003-08-14 21:36:52

"Jeff Garland" <jeff_at_[hidden]> wrote in message
news:20030812114756.M49204_at_crystalclearsoftware.com...
> Another user has submitted a change to me, that hasn't made it into
> the library, that performs the equivalent by modifying
adjust_functors.hpp.
> Looking back on the history of the number of requests on this it looks
like
> it should be a priority to officially support this option.  Or perhaps,
even
> better, to step up and support bi-directional or random access iterators.

I think the big issue in using random access iterators is whether you want
to support the difference concept. It is relatively straightforward to
implement, say

year_iterator i(date(2003,1,1));
year_iterator j(date(2005,1,1));
cout << j - i;    // prints "2"

but how do you handle the case when the dates are not neatly aligned on the
places where the iterator would normally put them?

I have one more question/suggestion.

Your period concept supports the merge (ie. union) function, which returns
an empty period if there is no intersection. I also have a need for a
function returning the actual [earliest,latest) of the two periods,
regardless of whether they intersect. Obviously, this is trival to write,
but it would be nice if the concept was included in the library.

Chris