boost/unordered/detail/foa/tuple_rotate_right.hpp

/* Copyright 2023-2024 Joaquin M Lopez Munoz.
 * 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)
 *
 * See https://www.boost.org/libs/unordered for library home page.
 */

#ifndef BOOST_UNORDERED_DETAIL_FOA_TUPLE_ROTATE_RIGHT_HPP
#define BOOST_UNORDERED_DETAIL_FOA_TUPLE_ROTATE_RIGHT_HPP

#include <boost/mp11/algorithm.hpp>
#include <boost/mp11/integer_sequence.hpp>
#include <tuple>
#include <utility>

namespace boost{
namespace unordered{
namespace detail{
namespace foa{

template<std::size_t Offset,typename Tuple>
using tuple_rotate_right_return_type=mp11::mp_rotate_right_c<
  typename std::remove_cv<typename std::remove_reference<Tuple>::type>::type,
  Offset
>;

template<std::size_t Offset,std::size_t... Is,typename Tuple>
tuple_rotate_right_return_type<Offset,Tuple>
tuple_rotate_right_aux(mp11::index_sequence<Is...>,Tuple&& x)
{
  return tuple_rotate_right_return_type<Offset,Tuple>{
    std::get<(Is+sizeof...(Is)-Offset)%sizeof...(Is)>(
      std::forward<Tuple>(x))...};
}

template<std::size_t Offset=1,typename Tuple>
tuple_rotate_right_return_type<Offset,Tuple> tuple_rotate_right(Tuple&& x)
{
  using RawTuple=typename std::remove_cv<
    typename std::remove_reference<Tuple>::type>::type;

  return tuple_rotate_right_aux<Offset>(
    mp11::make_index_sequence<std::tuple_size<RawTuple>::value>{},
    std::forward<Tuple>(x));
}

} /* namespace foa */
} /* namespace detail */
} /* namespace unordered */
} /* namespace boost */

#endif

Boost C++ Libraries

boost/unordered/detail/foa/tuple_rotate_right.hpp