Re: [Boost-users] Boost.Range fancify please

Subject: Re: [Boost-users] Boost.Range fancify please
From: Eric Niebler (eric_at_[hidden])
Date: 2009-12-27 00:42:09

On 12/27/2009 4:33 PM, anony wrote:
> I have this variable definition:
>
> float vertices[][3] = {
>    {-1, -1,  1}, {1, -1,  1}, {1, 1,  1}, {-1, 1,  1},
>    {-1, -1, -1}, {1, -1, -1}, {1, 1, -1}, {-1, 1, -1}
>    };
>
> I want to scale all elements of vertices, by some constant, for now I do
> it like this:
>
> BOOST_FOREACH(float&  f, boost::make_iterator_range(
>    boost::begin(vertices[0]), boost::end(vertices[7])))

Yikes! You can't do that. The begin and end iterators point into 
different arrays.

> {
>    f *= scale;
> }
>
> But maybe something more beautiful could be done with Boost.Range?

Why not just use BOOST_FOREACH correctly?

   BOOST_FOREACH(float (&rgf)[3], vertices)
     BOOST_FOREACH(float& f, rgf)
       f *= scale;

HTH,

-- 
Eric Niebler
BoostPro Computing
http://www.boostpro.com