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Diffstat (limited to 'boost/fusion/adapted/std_tuple/detail/build_std_tuple.hpp')
-rw-r--r-- | boost/fusion/adapted/std_tuple/detail/build_std_tuple.hpp | 105 |
1 files changed, 105 insertions, 0 deletions
diff --git a/boost/fusion/adapted/std_tuple/detail/build_std_tuple.hpp b/boost/fusion/adapted/std_tuple/detail/build_std_tuple.hpp new file mode 100644 index 0000000000..41e0d434e8 --- /dev/null +++ b/boost/fusion/adapted/std_tuple/detail/build_std_tuple.hpp @@ -0,0 +1,105 @@ +/*============================================================================= + Copyright (c) 2014 Kohei Takahashi + + 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) +==============================================================================*/ +#if !defined(BOOST_FUSION_BUILD_STD_TUPLE_05292014_0100) +#define BOOST_FUSION_BUILD_STD_TUPLE_05292014_0100 + +#include <boost/mpl/eval_if.hpp> +#include <boost/mpl/identity.hpp> +#include <boost/fusion/support/config.hpp> +#include <boost/fusion/iterator/equal_to.hpp> +#include <boost/fusion/iterator/next.hpp> +#include <boost/fusion/iterator/value_of.hpp> +#include <boost/fusion/iterator/deref.hpp> +#include <tuple> + +namespace boost { namespace fusion { namespace detail +{ + template <typename First, typename Last + , bool is_empty = result_of::equal_to<First, Last>::value + > + struct build_std_tuple; + + template <typename First, typename Last> + struct build_std_tuple<First, Last, true> + { + typedef std::tuple<> type; + BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED + static type + call(First const&, Last const&) + { + return type(); + } + }; + + template <int ...> struct indexed_tuple { }; + + template <int, typename = indexed_tuple<>> + struct make_indexed_tuple; + + template <int Head, int ...Tail> + struct make_indexed_tuple<Head, indexed_tuple<Tail...>> + { + typedef typename + boost::mpl::eval_if_c< + (Head == 0), + boost::mpl::identity<indexed_tuple<Tail...>>, + make_indexed_tuple<Head - 1, indexed_tuple<Head - 1, Tail...>> + >::type + type; + }; + + template <typename T, typename Rest> + struct push_front_std_tuple; + + template <typename T, typename ...Rest> + struct push_front_std_tuple<T, std::tuple<Rest...>> + { + typedef std::tuple<T, Rest...> type; + + template <int ...I> + BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED + static type + indexed_call(T const& first, std::tuple<Rest...> const& rest, indexed_tuple<I...>) + { + return type(first, std::get<I>(rest)...); + } + + BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED + static type + call(T const& first, std::tuple<Rest...> const& rest) + { + typedef typename make_indexed_tuple<sizeof...(Rest)>::type gen; + return indexed_call(first, rest, gen()); + } + }; + + template <typename First, typename Last> + struct build_std_tuple<First, Last, false> + { + typedef + build_std_tuple<typename result_of::next<First>::type, Last> + next_build_std_tuple; + + typedef push_front_std_tuple< + typename result_of::value_of<First>::type + , typename next_build_std_tuple::type> + push_front; + + typedef typename push_front::type type; + + BOOST_CXX14_CONSTEXPR BOOST_FUSION_GPU_ENABLED + static type + call(First const& f, Last const& l) + { + typename result_of::value_of<First>::type v = *f; + return push_front::call( + v, next_build_std_tuple::call(fusion::next(f), l)); + } + }; +}}} + +#endif |