Re: [boost] [range] adaptors vs. rvalue to lvalue& binding

Subject: Re: [boost] [range] adaptors vs. rvalue to lvalue& binding
From: Dave Abrahams (dave_at_[hidden])
Date: 2012-03-23 11:20:16

on Thu Mar 22 2012, Dave Abrahams <dave-AT-boostpro.com> wrote:

> on Thu Mar 22 2012, Arno Schödl <aschoedl-AT-think-cell.com> wrote:
>
>> Hello,
>>
>> ideally I would like to use range-adapted lvalue ranges like any
>> other lvalue ranges. Writing it down naively, as below, does not
>> compile because LoadRefRange takes (and should take?) the range it
>> modifies by lvalue&, while adaptor expressions are rvalues.
>
> One possibility: 
>
>  - make adaptor expressions return const rvalues. The const rvalues will
>    bind to T& arguments (where T is a template parameter) by deducing T
>    to be const.
>
>  - make even the const_iterators for such adaptors mutable (writable) iterators
>
> This accurately reflects the fact that such adaptors don't own their values.

Bump.  Did nobody understand this suggestion?  Bad idea for some reason?
Or...?

-- 
Dave Abrahams
BoostPro Computing
http://www.boostpro.com