Re: [Boost-users] [Boost.Assign] list_of::range without an initial (single) element?

Subject: Re: [Boost-users] [Boost.Assign] list_of::range without an initial (single) element?
From: er (erwann.rogard_at_[hidden])
Date: 2010-06-17 00:52:05

> 
> I have to look more deeply into the new proposal for operator&&(), but 
> it seems a little specific.  Is there no way that the ideas discussed 

operator && is fairly general as it works for any pair of ranges and is 
composable:

     v1 && v2 && v3

It also preserves lvalue-ness e.g.

     boost::copy(
         v4,
         boost::begin( v1 && v2 )
     );

Either of v1 and v2, here, can be a range of reference wrappers, so, for 
example, this call to copy could be preceded by

     BOOST_AUTO(v1,ref_csv(a,b,c)); // v1 is an array of ref-wrappers
     std::vector<int> v2(2);

Internally it uses chain.hpp from RangeEx. By the way, I didn't see it 
in the latest release, so I've made the file temporarily avail here:

   http://svn.boost.org/svn/boost/sandbox/statistics/support/boost/range/

> here could be made as efficient, requiring a separate operator&&() for 
> chaining?  As a user, I would not mind being steered towards the 
> efficient usage if documented properly.

If you have specifics in mind, please let us know.

http://svn.boost.org/svn/boost/sandbox/statistics/support/libs/assign/doc/index.html#ref-chain

Thanks.