text: // Copyright (c) 2018 Adam Butcher, Antony Polukhin
  // Copyright (c) 2019-2020 Antony Polukhin
  //
  // Distributed under the Boost Software License, Version 1.0. (See accompanying
  // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
  
  #ifndef BOOST_PFR_DETAIL_TIE_FROM_STRUCTURE_TUPLE_HPP
  #define BOOST_PFR_DETAIL_TIE_FROM_STRUCTURE_TUPLE_HPP
  #pragma once
  
  #include <boost/pfr/detail/config.hpp>
  
  #include <boost/pfr/detail/core.hpp>
  
  #include <boost/pfr/detail/stdtuple.hpp>
  #include <boost/pfr/tuple_size.hpp>
  #include <boost/pfr/detail/make_integer_sequence.hpp>
  
  #include <tuple>
  
  namespace boost { namespace pfr { namespace detail {
  
  /// \brief A `std::tuple` capable of de-structuring assignment used to support
  /// a tie of multiple lvalue references to fields of an aggregate T.
  ///
  /// \sa boost::pfr::tie_from_structure
  template <typename... Elements>
  struct tie_from_structure_tuple : std::tuple<Elements&...> {
      using base = std::tuple<Elements&...>;
      using base::base;
  
      template <typename T>
      constexpr tie_from_structure_tuple& operator= (T const& t) {
          base::operator=(
              detail::make_stdtiedtuple_from_tietuple(
                  detail::tie_as_tuple(t),
                  detail::make_index_sequence<tuple_size_v<T>>()));
          return *this;
      }
  };
  
  }}} // boost::pfr::detail
  
  #endif // BOOST_PFR_DETAIL_TIE_FROM_STRUCTURE_TUPLE_HPP
  