container/map/map_iterator.hpp

0001 /*=============================================================================
0002     Copyright (c) 2005-2013 Joel de Guzman
0003     Copyright (c) 2005-2006 Dan Marsden
0004
0005     Distributed under the Boost Software License, Version 1.0. (See accompanying
0006     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
0007 ==============================================================================*/
0008 #if !defined(BOOST_FUSION_MAP_ITERATOR_02042013_0835)
0009 #define BOOST_FUSION_MAP_ITERATOR_02042013_0835
0010
0011 #include <boost/fusion/support/config.hpp>
0012 #include <boost/fusion/iterator/iterator_facade.hpp>
0013 #include <boost/mpl/minus.hpp>
0014 #include <boost/mpl/equal_to.hpp>
0015 #include <boost/mpl/if.hpp>
0016 #include <boost/utility/declval.hpp>
0017 #include <boost/type_traits/is_const.hpp>
0018 #include <boost/type_traits/add_const.hpp>
0019
0020 #ifdef _MSC_VER
0021 #  pragma warning(push)
0022 #  pragma warning(disable: 4512) // assignment operator could not be generated.
0023 #endif
0024
0025 namespace boost { namespace fusion
0026 {
0027     struct random_access_traversal_tag;
0028
0029     template <typename Seq, int Pos>
0030     struct map_iterator
0031         : iterator_facade<
0032             map_iterator<Seq, Pos>
0033           , typename Seq::category>
0034     {
0035         typedef Seq sequence;
0036         typedef mpl::int_<Pos> index;
0037
0038         BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
0039         map_iterator(Seq& seq)
0040             : seq_(seq)
0041         {}
0042
0043         template<typename Iterator>
0044         struct value_of
0045         {
0046             typedef typename Iterator::sequence sequence;
0047             typedef typename Iterator::index index;
0048             typedef
0049                 decltype(boost::declval<sequence>().get_val(index()))
0050             type;
0051         };
0052
0053         template<typename Iterator>
0054         struct value_of_data
0055         {
0056             typedef typename Iterator::sequence sequence;
0057             typedef typename Iterator::index index;
0058             typedef
0059                 decltype(boost::declval<sequence>().get_val(index()).second)
0060             type;
0061         };
0062
0063         template<typename Iterator>
0064         struct key_of
0065         {
0066             typedef typename Iterator::sequence sequence;
0067             typedef typename Iterator::index index;
0068             typedef decltype(boost::declval<sequence>().get_key(index())) key_identity_type;
0069             typedef typename key_identity_type::type type;
0070         };
0071
0072         template<typename Iterator>
0073         struct deref
0074         {
0075             typedef typename Iterator::sequence sequence;
0076             typedef typename Iterator::index index;
0077             typedef
0078                 decltype(boost::declval<sequence>().get(index()))
0079             type;
0080
0081             BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
0082             static type
0083             call(Iterator const& it)
0084             {
0085                 return it.seq_.get(typename Iterator::index());
0086             }
0087         };
0088
0089         template<typename Iterator>
0090         struct deref_data
0091         {
0092             typedef typename Iterator::sequence sequence;
0093             typedef typename Iterator::index index;
0094
0095             typedef decltype(boost::declval<sequence>().get(index()).second) second_type_;
0096
0097             typedef typename
0098                 mpl::if_<
0099                     is_const<sequence>
0100                   , typename add_const<second_type_>::type
0101                   , second_type_
0102                 >::type
0103             second_type;
0104
0105             typedef typename add_reference<second_type>::type type;
0106
0107             BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
0108             static type
0109             call(Iterator const& it)
0110             {
0111                 return it.seq_.get(typename Iterator::index()).second;
0112             }
0113         };
0114
0115         template <typename Iterator, typename N>
0116         struct advance
0117         {
0118             typedef typename Iterator::index index;
0119             typedef typename Iterator::sequence sequence;
0120             typedef map_iterator<sequence, index::value + N::value> type;
0121
0122             BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
0123             static type
0124             call(Iterator const& i)
0125             {
0126                 return type(i.seq_);
0127             }
0128         };
0129
0130         template<typename Iterator>
0131         struct next
0132             : advance<Iterator, mpl::int_<1> >
0133         {};
0134
0135         template<typename Iterator>
0136         struct prior
0137             : advance<Iterator, mpl::int_<-1> >
0138         {};
0139
0140         template <typename I1, typename I2>
0141         struct distance
0142         {
0143             typedef typename
0144                 mpl::minus<
0145                     typename I2::index, typename I1::index
0146                 >::type
0147             type;
0148
0149             BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
0150             static type
0151             call(I1 const&, I2 const&)
0152             {
0153                 return type();
0154             }
0155         };
0156
0157         template<typename I1, typename I2>
0158         struct equal_to
0159             : mpl::equal_to<typename I1::index, typename I2::index>
0160         {};
0161
0162         Seq& seq_;
0163     };
0164 }}
0165
0166 #ifdef _MSC_VER
0167 #  pragma warning(pop)
0168 #endif
0169
0170 #ifdef BOOST_FUSION_WORKAROUND_FOR_LWG_2408
0171 namespace std
0172 {
0173     template <typename Seq, int Pos>
0174     struct iterator_traits< ::boost::fusion::map_iterator<Seq, Pos> >
0175     { };
0176 }
0177 #endif
0178
0179 #endif