Re: [Boost-users] [Boost][DateTime] Non conforming iterators?

Subject: Re: [Boost-users] [Boost][DateTime] Non conforming iterators?
From: Arne Vogel (avogel_at_[hidden])
Date: 2015-06-29 05:22:52

Hi,

On 25.06.2015 14:53, dariomt_at_[hidden] wrote:
> Compilation on gcc and clang fails with a similar error complaining 
> about the lack of 'difference_type'.
>
> Isn't a nested difference_type a requirement of BidirectionalIterator?

Not entirely. An algorithm should use std::iterator_traits to access 
these types. Among other things this will ensure the algorithm works 
with pointers. The primary template tries to use nested types within the 
iterator's class or struct (if any). It seems that DateTime fails to 
provide all types as nested types *and* fails to specialize 
std::iterator_traits so it would not have to.

But I must admit I only did a cursory "grep" (v 1.55.0).

> Am I using these date iterators incorrectly?

It looks correct to me though I don't use DateTime a lot. It does seem 
the required difference_type is not provided by month_iterator. I'd 
suggest you check whether this was reported as a bug before, or maybe 
already fixed in the master branch.

> Regards
>

Cheers,
Arne Vogel