adapted/mpl/mpl_iterator.hpp

0001 /*=============================================================================
0002     Copyright (c) 2001-2011 Joel de Guzman
0003
0004     Distributed under the Boost Software License, Version 1.0. (See accompanying
0005     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
0006 ==============================================================================*/
0007 #if !defined(FUSION_MPL_ITERATOR_05052005_0731)
0008 #define FUSION_MPL_ITERATOR_05052005_0731
0009
0010 #include <boost/fusion/support/config.hpp>
0011 #include <boost/fusion/support/detail/mpl_iterator_category.hpp>
0012 #include <boost/fusion/iterator/iterator_facade.hpp>
0013 #include <boost/type_traits/remove_const.hpp>
0014 #include <boost/mpl/deref.hpp>
0015 #include <boost/mpl/next.hpp>
0016 #include <boost/mpl/prior.hpp>
0017 #include <boost/mpl/advance.hpp>
0018 #include <boost/mpl/distance.hpp>
0019
0020 namespace boost { namespace fusion
0021 {
0022     template <typename Iterator_>
0023     struct mpl_iterator
0024         : iterator_facade<
0025             mpl_iterator<Iterator_>
0026           , typename detail::mpl_iterator_category<typename Iterator_::category>::type
0027         >
0028     {
0029         typedef typename remove_const<Iterator_>::type iterator_type;
0030
0031         template <typename Iterator>
0032         struct value_of : mpl::deref<typename Iterator::iterator_type> {};
0033
0034         template <typename Iterator>
0035         struct deref
0036         {
0037             typedef typename mpl::deref<
0038                 typename Iterator::iterator_type>::type
0039             type;
0040
0041             BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
0042             static type
0043             call(Iterator)
0044             {
0045                 return type();
0046             }
0047         };
0048
0049         template <typename Iterator>
0050         struct next
0051         {
0052             typedef mpl_iterator<
0053                 typename mpl::next<typename Iterator::iterator_type>::type>
0054             type;
0055
0056             BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
0057             static type
0058             call(Iterator)
0059             {
0060                 return type();
0061             }
0062         };
0063
0064         template <typename Iterator>
0065         struct prior
0066         {
0067             typedef mpl_iterator<
0068                 typename mpl::prior<typename Iterator::iterator_type>::type>
0069             type;
0070
0071             BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
0072             static type
0073             call(Iterator)
0074             {
0075                 return type();
0076             }
0077         };
0078
0079         template <typename Iterator, typename N>
0080         struct advance
0081         {
0082             typedef mpl_iterator<
0083                 typename mpl::advance<typename Iterator::iterator_type, N>::type>
0084             type;
0085
0086             BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
0087             static type
0088             call(Iterator const& /*i*/)
0089             {
0090                 return type();
0091             }
0092         };
0093
0094         template <typename I1, typename I2>
0095         struct distance :
0096             mpl::distance<
0097                 typename I1::iterator_type
0098               , typename I2::iterator_type>
0099         {
0100             typedef typename
0101                 mpl::distance<
0102                     typename I1::iterator_type
0103                   , typename I2::iterator_type
0104                 >::type
0105             type;
0106
0107             BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
0108             static type
0109             call(I1 const&, I2 const&)
0110             {
0111                 return type();
0112             }
0113         };
0114     };
0115 }}
0116
0117 #ifdef BOOST_FUSION_WORKAROUND_FOR_LWG_2408
0118 namespace std
0119 {
0120     template <typename Iterator>
0121     struct iterator_traits< ::boost::fusion::mpl_iterator<Iterator> >
0122     { };
0123 }
0124 #endif
0125
0126 #endif
0127
0128