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

On Sat, Dec 26, 2009 at 10:45 PM, OvermindDL1 wrote:

On Sat, Dec 26, 2009 at 8:33 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]))) {  f *= scale; }

Are you sure that is correct, you are only multiplying the first 7 floats (out of 8*3=24)...

On Sat, Dec 26, 2009 at 8:33 PM, anony wrote:

...

But maybe something more beautiful could be done with Boost.Range?

Actually you could make it more 'beautiful' (as in shorter code) using fusion+phoenix if it really is a constant sized array like you have.

This is probably not correct, but I am at work right now so cannot check:

using namespace boost::fusion; using namespace boost::phoenix; using boost::array;

array,8> vertices = {  {-1, -1,  1}, {1, -1,  1}, {1, 1,  1}, {-1, 1,  1},  {-1, -1, -1}, {1, -1, -1}, {1, 1, -1}, {-1, 1, -1}  };

for_each(vertices,arg0*=val(scale));  // one line of code

Else, if it is not a static size, then yeah, do what Eric said, even then his way is short enough that you may as well use it regardless.

Er, you will need to joint view the sub array parts or something. It is easy to do, I am just a bit brain-dead right now, sleep...