1/*=============================================================================
2 Copyright (c) 2001-2011 Joel de Guzman
3 Copyright (c) 2005-2006 Dan Marsden
4
5 Distributed under the Boost Software License, Version 1.0. (See accompanying
6 file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
7==============================================================================*/
8#if !defined(FUSION_PREV_IMPL_13122005_2110)
9#define FUSION_PREV_IMPL_13122005_2110
10
11#include <boost/fusion/support/config.hpp>
12#include <boost/fusion/iterator/prior.hpp>
13
14namespace boost { namespace fusion
15{
16 struct transform_view_iterator_tag;
17 struct transform_view_iterator2_tag;
18
19 template<typename First, typename F>
20 struct transform_view_iterator;
21
22 template <typename First1, typename First2, typename F>
23 struct transform_view_iterator2;
24
25 namespace extension
26 {
27 template<typename Tag>
28 struct prior_impl;
29
30 // Unary Version
31 template<>
32 struct prior_impl<transform_view_iterator_tag>
33 {
34 template<typename Iterator>
35 struct apply
36 {
37 typedef typename Iterator::first_type first_type;
38 typedef typename result_of::prior<first_type>::type prior_type;
39 typedef typename Iterator::transform_type transform_type;
40 typedef transform_view_iterator<prior_type, transform_type> type;
41
42 BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
43 static type
44 call(Iterator const& i)
45 {
46 return type(fusion::prior(i.first), i.f);
47 }
48 };
49 };
50
51 // Binary Version
52 template<>
53 struct prior_impl<transform_view_iterator2_tag>
54 {
55 template<typename Iterator>
56 struct apply
57 {
58 typedef typename Iterator::first1_type first1_type;
59 typedef typename Iterator::first2_type first2_type;
60 typedef typename result_of::prior<first1_type>::type prior1_type;
61 typedef typename result_of::prior<first2_type>::type prior2_type;
62 typedef typename Iterator::transform_type transform_type;
63 typedef transform_view_iterator2<prior1_type, prior2_type, transform_type> type;
64
65 BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
66 static type
67 call(Iterator const& i)
68 {
69 return type(fusion::prior(i.first1), fusion::prior(i.first2), i.f);
70 }
71 };
72 };
73 }
74}}
75
76#endif
77