adapted/boost_array/array_iterator.hpp

0001 /*=============================================================================
0002     Copyright (c) 2001-2011 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_ARRAY_ITERATOR_26122005_2250)
0009 #define BOOST_FUSION_ARRAY_ITERATOR_26122005_2250
0010
0011 #include <boost/fusion/support/config.hpp>
0012 #include <cstddef>
0013 #include <boost/config.hpp>
0014 #include <boost/mpl/int.hpp>
0015 #include <boost/mpl/assert.hpp>
0016 #include <boost/mpl/if.hpp>
0017 #include <boost/mpl/minus.hpp>
0018 #include <boost/type_traits/is_const.hpp>
0019 #include <boost/fusion/iterator/iterator_facade.hpp>
0020
0021 #ifdef _MSC_VER
0022 #  pragma warning(push)
0023 #  pragma warning(disable: 4512) // assignment operator could not be generated.
0024 #endif
0025
0026 namespace boost { namespace fusion
0027 {
0028     struct random_access_traversal_tag;
0029
0030     template <typename Array, int Pos>
0031     struct array_iterator
0032         : iterator_facade<array_iterator<Array, Pos>, random_access_traversal_tag>
0033     {
0034         BOOST_MPL_ASSERT_RELATION(Pos, >=, 0);
0035         BOOST_MPL_ASSERT_RELATION(Pos, <=, static_cast<int>(Array::static_size));
0036
0037         typedef mpl::int_<Pos> index;
0038         typedef Array array_type;
0039
0040         BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
0041         array_iterator(Array& a)
0042             : array(a) {}
0043
0044         Array& array;
0045
0046         template <typename Iterator>
0047         struct value_of
0048         {
0049             typedef typename Iterator::array_type array_type;
0050             typedef typename array_type::value_type type;
0051         };
0052
0053         template <typename Iterator>
0054         struct deref
0055         {
0056             typedef typename Iterator::array_type array_type;
0057             typedef typename
0058                 mpl::if_<
0059                     is_const<array_type>
0060                   , typename array_type::const_reference
0061                   , typename array_type::reference
0062                 >::type
0063             type;
0064
0065             BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
0066             static type
0067             call(Iterator const & it)
0068             {
0069                 return it.array[Iterator::index::value];
0070             }
0071         };
0072
0073         template <typename Iterator, typename N>
0074         struct advance
0075         {
0076             typedef typename Iterator::index index;
0077             typedef typename Iterator::array_type array_type;
0078             typedef array_iterator<array_type, index::value + N::value> type;
0079
0080             BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
0081             static type
0082             call(Iterator const& i)
0083             {
0084                 return type(i.array);
0085             }
0086         };
0087
0088         template <typename Iterator>
0089         struct next : advance<Iterator, mpl::int_<1> > {};
0090
0091         template <typename Iterator>
0092         struct prior : advance<Iterator, mpl::int_<-1> > {};
0093
0094         template <typename I1, typename I2>
0095         struct distance : mpl::minus<typename I2::index, typename I1::index>
0096         {
0097             typedef typename
0098                 mpl::minus<
0099                     typename I2::index, typename I1::index
0100                 >::type
0101             type;
0102
0103             BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
0104             static type
0105             call(I1 const&, I2 const&)
0106             {
0107                 return type();
0108             }
0109         };
0110     };
0111 }}
0112
0113 #ifdef _MSC_VER
0114 #  pragma warning(pop)
0115 #endif
0116
0117 #ifdef BOOST_FUSION_WORKAROUND_FOR_LWG_2408
0118 namespace std
0119 {
0120     template <typename Array, int Pos>
0121     struct iterator_traits< ::boost::fusion::array_iterator<Array, Pos> >
0122     { };
0123 }
0124 #endif
0125
0126 #endif