1/*=============================================================================
2 Copyright (c) 2014,2018 Kohei Takahashi
3
4 Distributed under the Boost Software License, Version 1.0. (See accompanying
5 file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
6==============================================================================*/
7#ifndef FUSION_VALUE_AT_IMPL_16122014_1641
8#define FUSION_VALUE_AT_IMPL_16122014_1641
9
10#include <boost/fusion/support/config.hpp>
11#include <boost/fusion/container/vector/detail/config.hpp>
12
13///////////////////////////////////////////////////////////////////////////////
14// Without variadics, we will use the PP version
15///////////////////////////////////////////////////////////////////////////////
16#if !defined(BOOST_FUSION_HAS_VARIADIC_VECTOR)
17# include <boost/fusion/container/vector/detail/cpp03/value_at_impl.hpp>
18#else
19
20///////////////////////////////////////////////////////////////////////////////
21// C++11 interface
22///////////////////////////////////////////////////////////////////////////////
23#include <boost/fusion/container/vector/vector_fwd.hpp>
24#include <boost/type_traits/declval.hpp>
25#include <boost/mpl/identity.hpp>
26
27namespace boost { namespace fusion
28{
29 struct vector_tag;
30
31 namespace vector_detail
32 {
33 template <std::size_t I, typename T>
34 struct store;
35
36 template <std::size_t N, typename U>
37 static inline BOOST_FUSION_GPU_ENABLED
38 mpl::identity<U> value_at_impl(store<N, U> const volatile*);
39 }
40
41 namespace extension
42 {
43 template <typename Tag>
44 struct value_at_impl;
45
46 template <>
47 struct value_at_impl<vector_tag>
48 {
49 template <typename Sequence, typename N>
50 struct apply : BOOST_FUSION_DECLTYPE_N3031((
51 vector_detail::value_at_impl<N::value>(boost::declval<Sequence*>())
52 ))
53 {};
54 };
55 }
56}}
57
58#endif
59#endif
60
61