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_BEGIN_IMPL_07162005_0115)
8#define FUSION_BEGIN_IMPL_07162005_0115
9
10#include <boost/fusion/support/config.hpp>
11#include <boost/fusion/iterator/equal_to.hpp>
12#include <boost/mpl/if.hpp>
13
14namespace boost { namespace fusion
15{
16 struct joint_view_tag;
17
18 template <typename Category, typename First, typename Last, typename Concat>
19 struct joint_view_iterator;
20
21 namespace extension
22 {
23 template <typename Tag>
24 struct begin_impl;
25
26 template <>
27 struct begin_impl<joint_view_tag>
28 {
29 template <typename Sequence>
30 struct apply
31 {
32 typedef typename Sequence::first_type first_type;
33 typedef typename Sequence::last_type last_type;
34 typedef typename Sequence::concat_type concat_type;
35 typedef typename Sequence::category category;
36 typedef result_of::equal_to<first_type, last_type> equal_to;
37
38 typedef typename
39 mpl::if_<
40 equal_to
41 , concat_type
42 , joint_view_iterator<category, first_type, last_type, concat_type>
43 >::type
44 type;
45
46 BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
47 static type
48 call(Sequence& s, mpl::true_)
49 {
50 return s.concat();
51 }
52
53 BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
54 static type
55 call(Sequence& s, mpl::false_)
56 {
57 return type(s.first(), s.concat());
58 }
59
60 BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
61 static type
62 call(Sequence& s)
63 {
64 return call(s, equal_to());
65 }
66 };
67 };
68 }
69}}
70
71#endif
72

source code of include/boost/fusion/view/joint_view/detail/begin_impl.hpp