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_SIZE_05052005_0214)
8#define FUSION_SIZE_05052005_0214
9
10#include <boost/fusion/support/config.hpp>
11#include <boost/utility/enable_if.hpp>
12#include <boost/mpl/if.hpp>
13#include <boost/mpl/int.hpp>
14#include <boost/fusion/sequence/intrinsic_fwd.hpp>
15#include <boost/fusion/support/tag_of.hpp>
16#include <boost/fusion/support/is_segmented.hpp>
17#include <boost/fusion/sequence/intrinsic/detail/segmented_size.hpp>
18
19namespace boost { namespace fusion
20{
21 // Special tags:
22 struct sequence_facade_tag;
23 struct boost_tuple_tag; // boost::tuples::tuple tag
24 struct boost_array_tag; // boost::array tag
25 struct mpl_sequence_tag; // mpl sequence tag
26 struct std_pair_tag; // std::pair tag
27
28 namespace extension
29 {
30 template <typename Tag>
31 struct size_impl
32 {
33 template<typename Sequence>
34 struct unsegmented_size : Sequence::size {};
35
36 template <typename Sequence>
37 struct apply
38 : mpl::if_<
39 traits::is_segmented<Sequence>
40 , detail::segmented_size<Sequence>
41 , unsegmented_size<Sequence>
42 >::type
43 {};
44 };
45
46 template <>
47 struct size_impl<sequence_facade_tag>
48 {
49 template <typename Sequence>
50 struct apply : Sequence::template size<Sequence> {};
51 };
52
53 template <>
54 struct size_impl<boost_tuple_tag>;
55
56 template <>
57 struct size_impl<boost_array_tag>;
58
59 template <>
60 struct size_impl<mpl_sequence_tag>;
61
62 template <>
63 struct size_impl<std_pair_tag>;
64 }
65
66 namespace result_of
67 {
68 template <typename Sequence>
69 struct size
70 : mpl::int_<
71 extension::size_impl<typename detail::tag_of<Sequence>::type>
72 ::template apply<Sequence>::type::value
73 > {};
74 }
75
76 template <typename Sequence>
77 BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
78 inline typename result_of::size<Sequence>::type
79 size(Sequence const&)
80 {
81 typedef typename result_of::size<Sequence>::type result;
82 return result();
83 }
84}}
85
86#endif
87

source code of include/boost/fusion/sequence/intrinsic/size.hpp