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 
19 namespace 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
size(Sequence const &)79     size(Sequence const&)
80     {
81         typedef typename result_of::size<Sequence>::type result;
82         return result();
83     }
84 }}
85 
86 #endif
87