#include <utility>
#include <boost/assert.hpp>
#include <boost/range/adaptor/map.hpp>
#include <boost/range/algorithm/equal.hpp>
#include <boost/range/algorithm/copy.hpp>

int main()
{
    const std::pair<int, char> ar[] = {
        std::make_pair(3, 'a'),
        std::make_pair(1, 'b'),
        std::make_pair(4, 'c')
    };

    {
        const int expected[] = {3, 1, 4};
        BOOST_ASSERT(boost::equal(ar | boost::adaptors::map_keys, expected));
    }

    {
        const char expected[] = { 'a', 'b', 'c' };
        BOOST_ASSERT(boost::equal(ar | boost::adaptors::map_values, expected));
    }

    // mutable version
    {
        std::pair<int, char> mar[3];
        boost::copy(ar, boost::begin(mar));

        const char expected[] = { 'a', 'b', 'c' };
        BOOST_ASSERT(boost::equal(mar | boost::adaptors::map_values, expected));
    }
}