Re: [boost] [range] Should ranges really propagate constess to the data ?

Subject: Re: [boost] [range] Should ranges really propagate constess to the data ?
From: Jeffrey Lee Hellrung, Jr. (jeffrey.hellrung_at_[hidden])
Date: 2011-07-24 15:43:58

On Sun, Jul 24, 2011 at 6:41 AM, Neil Groves <neil_at_[hidden]>wrote:
[...]

> I am currently considering the possible changes we could make to sub_range.
> Ultimately sub_range is implemented as the original author intended.

As I had inferred, given how the documentation explicitly mentions the
propagation of const'ness.

[...]

> How do you imagine the const / mutable underlying iterator would be chosen?
> If you are proposing that the const-ness of the sub_range template
> parameter
> is used, I think that this would break to much existing code. The current
> semantics have been in place since at least version 1.33.
>

That's a legitimate concern.

> I do agree that sub_range's behaviour is rarely required or desirable. My
> approach has been to use iterator_range for most of my code. I imagine that
> you would prefer a class similar to iterator_range differing in so much as
> it takes a Range or const Range as the template parameter. I'll give this
> some more thought. I would like to avoid the proliferation of similar
> classes, and breaking interface changes, but I am motivated to provide a
> solution for your use case.
>

I'm not sure what to do either, but I'm not opposed to "do nothing" :/
Maybe add some rationale for why sub_range propagates const'ness.

- Jeff