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

Subject: Re: [boost] [range] Should ranges really propagate constess to the data ?
From: Samuel Debionne (debionne_at_[hidden])
Date: 2011-07-26 04:55:25

Le 25/07/2011 21:38, Dave Abrahams a écrit :

> If the Range concept said that views must not propagate constness, that
> would be one thing... but it doesn't, does it?

Thank you all for clarifying this. Like Mathias, I have the feeling that 
Views should not propagate constness, but as I understand it now, Views 
are only a special case (refinement ?) of Ranges. Maybe there is room 
for a View concept that will be more specific about constness 
propagatation ?

I suggest two improvements in the documentation :

1. In the Range Concept Overview, add a note about constness 
propagation. Something along "the concept doesn't say anything about 
whether constness is propagated to the data.  If you want to write 
generic Range code you have to account for both cases."

2. In the subrange, make the sentence "the sub_range class do propagate 
constness since it knows what a corresponding const_iterator is" bring 
out as an important admonition since it is an unexpected behaviour.

Samuel