source: NonGTP/Boost/boost/mpl/pair_view.hpp @ 857

Revision 857, 4.5 KB checked in by igarcia, 19 years ago (diff)
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[857]1
2#ifndef BOOST_MPL_PAIR_VIEW_HPP_INCLUDED
3#define BOOST_MPL_PAIR_VIEW_HPP_INCLUDED
4
5// Copyright David Abrahams 2003-2004
6// Copyright Aleksey Gurtovoy 2004
7//
8// Distributed under the Boost Software License, Version 1.0.
9// (See accompanying file LICENSE_1_0.txt or copy at
10// http://www.boost.org/LICENSE_1_0.txt)
11//
12// See http://www.boost.org/libs/mpl for documentation.
13
14// $Source: /cvsroot/boost/boost/boost/mpl/pair_view.hpp,v $
15// $Date: 2004/11/28 01:56:21 $
16// $Revision: 1.5 $
17
18#include <boost/mpl/begin_end.hpp>
19#include <boost/mpl/iterator_category.hpp>
20#include <boost/mpl/advance.hpp>
21#include <boost/mpl/distance.hpp>
22#include <boost/mpl/next_prior.hpp>
23#include <boost/mpl/deref.hpp>
24#include <boost/mpl/min_max.hpp>
25#include <boost/mpl/pair.hpp>
26#include <boost/mpl/iterator_tags.hpp>
27#include <boost/mpl/aux_/config/ctps.hpp>
28#include <boost/mpl/aux_/na_spec.hpp>
29
30namespace boost { namespace mpl {
31
32namespace aux {
33struct pair_iter_tag;
34
35#if defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION)
36
37template< typename Iter1, typename Iter2, typename Category >
38struct pair_iter;
39
40template< typename Category > struct prior_pair_iter
41{
42    template< typename Iter1, typename Iter2 > struct apply
43    {
44        typedef typename mpl::prior<Iter1>::type i1_;
45        typedef typename mpl::prior<Iter2>::type i2_;
46        typedef pair_iter<i1_,i2_,Category> type;
47    };
48};
49
50template<> struct prior_pair_iter<forward_iterator_tag>
51{
52    template< typename Iter1, typename Iter2 > struct apply
53    {
54        typedef pair_iter<Iter1,Iter2,forward_iterator_tag> type;
55    };
56};
57
58#endif
59}
60
61template<
62      typename Iter1
63    , typename Iter2
64    , typename Category
65    >
66struct pair_iter
67{
68    typedef aux::pair_iter_tag tag;
69    typedef Category category;
70    typedef Iter1 first;
71    typedef Iter2 second;
72   
73#if defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION)
74    typedef pair<
75          typename deref<Iter1>::type
76        , typename deref<Iter2>::type
77        > type;
78
79    typedef typename mpl::next<Iter1>::type i1_;
80    typedef typename mpl::next<Iter2>::type i2_;
81    typedef pair_iter<i1_,i2_,Category> next;
82   
83    typedef apply_wrap2< aux::prior_pair_iter<Category>,Iter1,Iter2 >::type prior;
84#endif
85};
86
87
88#if !defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION)
89
90template< typename Iter1, typename Iter2, typename C >
91struct deref< pair_iter<Iter1,Iter2,C> >
92{
93    typedef pair<
94          typename deref<Iter1>::type
95        , typename deref<Iter2>::type
96        > type;
97};
98
99template< typename Iter1, typename Iter2, typename C >
100struct next< pair_iter<Iter1,Iter2,C> >
101{
102    typedef typename mpl::next<Iter1>::type i1_;
103    typedef typename mpl::next<Iter2>::type i2_;
104    typedef pair_iter<i1_,i2_,C> type;
105};
106
107template< typename Iter1, typename Iter2, typename C >
108struct prior< pair_iter<Iter1,Iter2,C> >
109{
110    typedef typename mpl::prior<Iter1>::type i1_;
111    typedef typename mpl::prior<Iter2>::type i2_;
112    typedef pair_iter<i1_,i2_,C> type;
113};
114
115#endif // BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
116
117
118template<> struct advance_impl<aux::pair_iter_tag>
119{
120    template< typename Iter, typename D > struct apply
121    {
122        typedef typename mpl::advance< typename Iter::first,D >::type i1_;
123        typedef typename mpl::advance< typename Iter::second,D >::type i2_;
124        typedef pair_iter<i1_,i2_,typename Iter::category> type;
125    };
126};
127
128template<> struct distance_impl<aux::pair_iter_tag>
129{
130    template< typename Iter1, typename Iter2 > struct apply
131    {
132        // agurt, 10/nov/04: MSVC 6.5 ICE-s on forwarding
133        typedef typename mpl::distance<
134              typename first<Iter1>::type
135            , typename first<Iter2>::type
136            >::type type;
137    };
138};
139
140
141template<
142      typename BOOST_MPL_AUX_NA_PARAM(Sequence1)
143    , typename BOOST_MPL_AUX_NA_PARAM(Sequence2)
144    >
145struct pair_view
146{
147    typedef nested_begin_end_tag tag;
148
149    typedef typename begin<Sequence1>::type iter1_;
150    typedef typename begin<Sequence2>::type iter2_;
151    typedef typename min<
152          typename iterator_category<iter1_>::type
153        , typename iterator_category<iter2_>::type
154        >::type category_;
155   
156    typedef pair_iter<iter1_,iter2_,category_> begin;
157   
158    typedef pair_iter<
159          typename end<Sequence1>::type
160        , typename end<Sequence2>::type
161        , category_
162        > end;
163};
164
165BOOST_MPL_AUX_NA_SPEC(2, pair_view)
166
167}}
168
169#endif // BOOST_MPL_PAIR_VIEW_HPP_INCLUDED
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