1/*=============================================================================
2 Copyright (c) 2001-2011 Joel de Guzman
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#if !defined(FUSION_IS_VIEW_03202006_0015)
8#define FUSION_IS_VIEW_03202006_0015
9
10#include <boost/fusion/support/config.hpp>
11#include <boost/mpl/bool.hpp>
12#include <boost/fusion/support/detail/is_view.hpp>
13#include <boost/fusion/support/tag_of.hpp>
14
15namespace boost { namespace fusion
16{
17 // Special tags:
18 struct sequence_facade_tag;
19 struct boost_tuple_tag; // boost::tuples::tuple tag
20 struct boost_array_tag; // boost::array tag
21 struct mpl_sequence_tag; // mpl sequence tag
22 struct std_pair_tag; // std::pair tag
23
24 namespace extension
25 {
26 template<typename Tag>
27 struct is_view_impl
28 {
29 template <typename T>
30 struct apply
31 : detail::fusion_is_view<T>
32 {};
33 };
34
35 template <>
36 struct is_view_impl<sequence_facade_tag>
37 {
38 template <typename Sequence>
39 struct apply : Sequence::is_view {};
40 };
41
42 template <>
43 struct is_view_impl<boost_tuple_tag>;
44
45 template <>
46 struct is_view_impl<boost_array_tag>;
47
48 template <>
49 struct is_view_impl<mpl_sequence_tag>;
50
51 template <>
52 struct is_view_impl<std_pair_tag>;
53 }
54
55 namespace traits
56 {
57 template <typename T>
58 struct is_view :
59 mpl::bool_<
60 (bool)extension::is_view_impl<typename fusion::detail::tag_of<T>::type>::
61 template apply<T>::type::value
62 >
63 {};
64 }
65}}
66
67#endif
68

source code of boost/boost/fusion/support/is_view.hpp