detail/foa/tuple_rotate_right.hpp

0001 /* Copyright 2023-2024 Joaquin M Lopez Munoz.
0002  * Distributed under the Boost Software License, Version 1.0.
0003  * (See accompanying file LICENSE_1_0.txt or copy at
0004  * http://www.boost.org/LICENSE_1_0.txt)
0005  *
0006  * See https://www.boost.org/libs/unordered for library home page.
0007  */
0008
0009 #ifndef BOOST_UNORDERED_DETAIL_FOA_TUPLE_ROTATE_RIGHT_HPP
0010 #define BOOST_UNORDERED_DETAIL_FOA_TUPLE_ROTATE_RIGHT_HPP
0011
0012 #include <boost/mp11/algorithm.hpp>
0013 #include <boost/mp11/integer_sequence.hpp>
0014 #include <tuple>
0015 #include <utility>
0016
0017 namespace boost{
0018 namespace unordered{
0019 namespace detail{
0020 namespace foa{
0021
0022 template<std::size_t Offset,typename Tuple>
0023 using tuple_rotate_right_return_type=mp11::mp_rotate_right_c<
0024   typename std::remove_cv<typename std::remove_reference<Tuple>::type>::type,
0025   Offset
0026 >;
0027
0028 template<std::size_t Offset,std::size_t... Is,typename Tuple>
0029 tuple_rotate_right_return_type<Offset,Tuple>
0030 tuple_rotate_right_aux(mp11::index_sequence<Is...>,Tuple&& x)
0031 {
0032   return tuple_rotate_right_return_type<Offset,Tuple>{
0033     std::get<(Is+sizeof...(Is)-Offset)%sizeof...(Is)>(
0034       std::forward<Tuple>(x))...};
0035 }
0036
0037 template<std::size_t Offset=1,typename Tuple>
0038 tuple_rotate_right_return_type<Offset,Tuple> tuple_rotate_right(Tuple&& x)
0039 {
0040   using RawTuple=typename std::remove_cv<
0041     typename std::remove_reference<Tuple>::type>::type;
0042
0043   return tuple_rotate_right_aux<Offset>(
0044     mp11::make_index_sequence<std::tuple_size<RawTuple>::value>{},
0045     std::forward<Tuple>(x));
0046 }
0047
0048 } /* namespace foa */
0049 } /* namespace detail */
0050 } /* namespace unordered */
0051 } /* namespace boost */
0052
0053 #endif