exercise-7-0.hpp

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// ===-- chapter-7/exercise-7-0.hpp ----------------------- -*- C++ -*- --=== //
#ifndef EXERCISE_7_0
#define EXERCISE_7_0
 
#include "chapter-7-zip_view.hpp"
 
#include <boost/static_assert.hpp>
 
#include <boost/mpl/copy.hpp>
#include <boost/mpl/back_inserter.hpp>
#include <boost/mpl/equal.hpp>
#include <boost/mpl/vector.hpp>
#include <boost/mpl/vector_c.hpp>
 
 
namespace exercise_7_0 {
using namespace chapter7;
 
// We're going to test our zip_view by just smashing two vectors together,
// interleaving the results.  This doesn't test laziness, but does test
// correctness.
 
typedef boost::mpl::vector_c<int, 1, 3, 5, 7> v1;
typedef boost::mpl::vector_c<int, 2, 4, 6, 8> v2;
typedef boost::mpl::vector<v1, v2> zip_vec;
 
typedef boost::mpl::fold<
    zip_view<zip_vec>,
    boost::mpl::vector<>,
    boost::mpl::copy<_2, boost::mpl::back_inserter<_1> >
>::type folded;
 
typedef boost::mpl::vector_c<int, 1, 2, 3, 4, 5, 6, 7, 8> expected_results;
BOOST_STATIC_ASSERT((boost::mpl::equal<expected_results, folded>::value));
 
} // namespace exercise_7_0
 
#endif // EXERCISE_7_0