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boost_fusion/include/boost/fusion/support/detail/index_sequence.hpp
2015-06-22 21:58:54 +09:00

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1.6 KiB
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/*=============================================================================
Copyright (c) 2015 Agustin K-ballo Berge
Copyright (c) 2015 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)
==============================================================================*/
#ifndef BOOST_FUSION_SUPPORT_DETAIL_INDEX_SEQUENCE_06232015_1038
#define BOOST_FUSION_SUPPORT_DETAIL_INDEX_SEQUENCE_06232015_1038
#include <boost/fusion/support/config.hpp>
#include <cstddef>
namespace boost { namespace fusion { namespace detail
{
template <std::size_t ...Ints>
struct index_sequence
{
typedef std::size_t value_type;
BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
static std::size_t size() BOOST_NOEXCEPT
{ return sizeof...(Ints); }
// non standard extension
typedef index_sequence type;
};
template <typename Left, typename Right>
struct _make_index_sequence_join;
template <std::size_t... Left, std::size_t... Right>
struct _make_index_sequence_join<
index_sequence<Left...>, index_sequence<Right...>
> : index_sequence<Left..., (sizeof...(Left) + Right)...>
{};
template <std::size_t N>
struct make_index_sequence
: _make_index_sequence_join<
typename make_index_sequence<N / 2>::type
, typename make_index_sequence<N - N / 2>::type
>
{};
template <>
struct make_index_sequence<1>
: index_sequence<0>
{};
template <>
struct make_index_sequence<0>
: index_sequence<>
{};
}}}
#endif