Re: [Boost-users] [mpl][fusion] Metafunction for extracting a type from a map

From: Christian Henning (chhenning_at_[hidden])
Date: 2007-03-22 18:54:35

Thanks Chris for the quick response. I was trying find_if but I don't
think it provides the whole solution. Below is the minimal example,
that doesn't compile since the static assertion fires.

#include "boost/mpl/vector.hpp"
#include <boost/mpl/find_if.hpp>

using namespace std;
using namespace boost;

typedef mpl::vector<char, char> vec_1;
typedef mpl::vector<char, int> vec_2;

typedef mpl::vector<vec_1, vec_2> mat;

typedef mpl::find_if<mat, is_same<mpl::_1, int> >::type iter;

int _tmain(int argc, _TCHAR* argv[])
{
   BOOST_STATIC_ASSERT(( is_same< mpl::deref<iter>::type, vec_2 >::value ));

        return 0;
}

Do you know what I'm missing here?

Christian