ceph/src/boost/boost/pfr/detail/stdtuple.hpp

   1 // Copyright (c) 2016-2022 Antony Polukhin
   2 //
   3 // Distributed under the Boost Software License, Version 1.0. (See accompanying
   4 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   5
   6 #ifndef BOOST_PFR_DETAIL_STDTUPLE_HPP
   7 #define BOOST_PFR_DETAIL_STDTUPLE_HPP
   8 #pragma once
   9
  10 #include <boost/pfr/detail/config.hpp>
  11
  12 #include <utility>      // metaprogramming stuff
  13 #include <tuple>
  14
  15 #include <boost/pfr/detail/sequence_tuple.hpp>
  16
  17 namespace boost { namespace pfr { namespace detail {
  18
  19 template <class T, std::size_t... I>
  20 constexpr auto make_stdtuple_from_tietuple(const T& t, std::index_sequence<I...>) noexcept {
  21     return std::make_tuple(
  22         boost::pfr::detail::sequence_tuple::get<I>(t)...
  23     );
  24 }
  25
  26 template <class T, std::size_t... I>
  27 constexpr auto make_stdtiedtuple_from_tietuple(const T& t, std::index_sequence<I...>) noexcept {
  28     return std::tie(
  29         boost::pfr::detail::sequence_tuple::get<I>(t)...
  30     );
  31 }
  32
  33 template <class T, std::size_t... I>
  34 constexpr auto make_conststdtiedtuple_from_tietuple(const T& t, std::index_sequence<I...>) noexcept {
  35     return std::tuple<
  36         std::add_lvalue_reference_t<std::add_const_t<
  37             std::remove_reference_t<decltype(boost::pfr::detail::sequence_tuple::get<I>(t))>
  38         >>...
  39     >(
  40         boost::pfr::detail::sequence_tuple::get<I>(t)...
  41     );
  42 }
  43
  44 }}} // namespace boost::pfr::detail
  45
  46 #endif // BOOST_PFR_DETAIL_STDTUPLE_HPP