cpp-useful-iterators/include/iterator/zip_iterator.hpp

#pragma once

#include <iterator>
#include <tuple>

#include "detail/arrow_proxy.h"

namespace iterator {
  template <typename... Iterators> class zip_iterator {
  public:
    using value_type = std::tuple<typename Iterators::value_type...>;
    using reference = std::tuple<typename Iterators::reference...>;
    using pointer = void; // tuple cannot be accessed by member
    using difference_type =
        std::common_type_t<typename Iterators::difference_type...>;
    using iterator_category =
        std::common_type_t<typename Iterators::iterator_category...>;

  private:
    std::tuple<Iterators...> iterators_;

  public:
    zip_iterator() = default;
    zip_iterator(Iterators &&... iters) : iterators_(iters...) {}

    reference operator*() const {
      return reference(*std::get<Iterators>(iterators_)...);
    }
  };
}

template <typename... Iterators>
iterator::zip_iterator<Iterators...> make_zip_iterator(Iterators &&... iters) {
  return {std::forward<Iterators>(iters)...};
}