#include "boost/range/adaptor/transformed.hpp"
#include "boost/range/algorithm/copy.hpp"
#include "boost/range/algorithm/max_element.hpp"
#include <iostream>
#include <vector>

struct double_int
{
    typedef int result_type;
    int operator()(int x) const { return x * 2; }
};

int main(int argc, const char* argv[])
{
    using namespace boost::adaptors;

    std::vector<int> input{1,2,3,4,5,6,7,8,9,10};

    std::cout << *boost::max_element(input | transformed(double_int())) << std::endl;
        
    return 0;
}