Re: [Boost-users] Another sub_range problem

From: Shunsuke Sogame (mb2act_at_[hidden])
Date: 2006-12-05 00:44:20

abir basak wrote:
> abir basak wrote:
> To make the problem little clearer,
> typedef boost::circular_buffer<int> cbi;
> typedef std::vector<int> vi;
> This code works,
> boost::sub_range<vi> get_range(vi& v,int from,int to){
>    return boost::sub_range<vi>(v.begin()+from,v.begin()+to);
> }
> But this don't.
> boost::sub_range<cbi> get_range(cbi& v,int from,int to){
>    return boost::sub_range<cbi>(v.begin()+from,v.begin()+to);
> }
> 

FWIW, under VC8, boost::sub_range is not always CopyConstructible.
You can prefer boost::iterator_range instead.
This behavior comes from the VC8 bug. (See: http://tinyurl.com/yb8ban)
Put simply, her implicitly-defined 
copy-constructor/copy-assignment-operator is not conforming.
IIRC, VC7.1 also has this bug under weird situation, but I'm not sure.

The copy-assignment-operator of boost::sub_range(CVS Head) seems to
be patched for that bug, but the copy-constructor seems not yet?

-- 
Shunsuke Sogame