/*=============================================================================
    Copyright (c) 2014,2018 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 FUSION_VALUE_AT_IMPL_16122014_1641
#define FUSION_VALUE_AT_IMPL_16122014_1641

#include <boost/fusion/support/config.hpp>
#include <boost/fusion/container/vector/detail/config.hpp>

///////////////////////////////////////////////////////////////////////////////
// Without variadics, we will use the PP version
///////////////////////////////////////////////////////////////////////////////
#if !defined(BOOST_FUSION_HAS_VARIADIC_VECTOR)
# include <boost/fusion/container/vector/detail/cpp03/value_at_impl.hpp>
#else

///////////////////////////////////////////////////////////////////////////////
// C++11 interface
///////////////////////////////////////////////////////////////////////////////
#include <boost/fusion/container/vector/vector_fwd.hpp>
#include <boost/type_traits/declval.hpp>
#include <boost/mpl/identity.hpp>

namespace boost {
namespace fusion {
struct vector_tag;

namespace vector_detail {
template <std::size_t I, typename T>
struct store;

template <std::size_t N, typename U>
static inline BOOST_FUSION_GPU_ENABLED
mpl::identity<U>
value_at_impl(store<N, U> const volatile*);
}

namespace extension {
template <typename Tag>
struct value_at_impl;

template <>
struct value_at_impl<vector_tag>
{
    template <typename Sequence, typename N>
    struct apply :
    BOOST_FUSION_DECLTYPE_N3031((
                                    vector_detail::value_at_impl<N::value>(boost::declval<Sequence*>())
                                ))
    {};
};
}
}
}

#endif
#endif
