#include <algorithm>
#include <cassert>
#include <iterator>
#include <vector>
#include <set>
#include <list>
#include <string>

/* implement selection_iterator and selection */

int main()
{
    // two of the same container type with same size
    {
        std::vector<int> a { 1, 3, 4 };
        std::vector<int> b { 0, 2, 5 };

        std::vector<int> result { 0, 1, 2, 3, 4, 5 };

        auto begin = selection(a.begin(), a.end(), b.begin(), b.end());
        auto end   = selection(a  .end(), a.end(), b  .end(), b.end());

        for (auto const& value : result)
        {
            assert(begin != end);
            assert(*begin++ == value);
        }
    }

    // two different container types with same size
    {
        std::list<double> a { 0.5, 1.0, 2.5 };
        std::vector<double> b { 1.5, 1.75, 2.25 };

        std::vector<double> result { 0.5, 1.0, 1.5, 1.75, 2.25, 2.5 };

        auto begin = selection(a.begin(), a.end(), b.begin(), b.end());
        auto end   = selection(a  .end(), a.end(), b  .end(), b.end());

        for (auto const& value : result)
        {
            assert(begin != end);
            assert(*begin++ == value);
        }
    }

    // two different containers, with one empty
    {
        std::list<std::string> a { "a", "b", "c" };
        std::set<std::string> b { };

        std::vector<std::string> result { "a", "b", "c" };

        auto begin = selection(a.begin(), a.end(), b.begin(), b.end());
        auto end   = selection(a  .end(), a.end(), b  .end(), b.end());

        for (auto const& value : result)
        {
            assert(begin != end);
            assert(*begin++ == value);
        }
    }
}