Chris@16: /*=============================================================================
Chris@16:     Copyright (c) 2001-2011 Joel de Guzman
Chris@16: 
Chris@16:     Distributed under the Boost Software License, Version 1.0. (See accompanying
Chris@16:     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
Chris@16: ==============================================================================*/
Chris@16: #if !defined(FUSION_ITERATOR_FACADE_09252006_1011)
Chris@16: #define FUSION_ITERATOR_FACADE_09252006_1011
Chris@16: 
Chris@101: #include <boost/fusion/support/config.hpp>
Chris@16: #include <boost/fusion/support/iterator_base.hpp>
Chris@16: #include <boost/fusion/iterator/detail/advance.hpp>
Chris@16: #include <boost/fusion/iterator/detail/distance.hpp>
Chris@16: #include <boost/fusion/support/category_of.hpp>
Chris@16: #include <boost/type_traits/is_same.hpp>
Chris@16: #include <boost/mpl/assert.hpp>
Chris@101: #include <boost/mpl/if.hpp>
Chris@16: 
Chris@16: namespace boost { namespace fusion
Chris@16: {
Chris@16:     struct iterator_facade_tag;
Chris@16: 
Chris@16:     template <typename Derived, typename Category>
Chris@16:     struct iterator_facade : iterator_base<Derived>
Chris@16:     {
Chris@16:         typedef iterator_facade_tag fusion_tag;
Chris@16:         typedef Derived derived_type;
Chris@16:         typedef Category category;
Chris@16: 
Chris@16:         // default implementation
Chris@16:         template <typename I1, typename I2>
Chris@16:         struct equal_to // default implementation
Chris@16:             : is_same<
Chris@16:                 typename I1::derived_type
Chris@16:               , typename I2::derived_type
Chris@16:             >
Chris@16:         {};
Chris@16: 
Chris@16:         // default implementation
Chris@16:         template <typename Iterator, typename N>
Chris@16:         struct advance :
Chris@16:             mpl::if_c<
Chris@16:                 (N::value > 0)
Chris@16:               , advance_detail::forward<Iterator, N::value>
Chris@16:               , advance_detail::backward<Iterator, N::value>
Chris@16:             >::type
Chris@16:         {
Chris@16:             BOOST_MPL_ASSERT_NOT((traits::is_random_access<Iterator>));
Chris@16:         };
Chris@16: 
Chris@16:         // default implementation
Chris@16:         template <typename First, typename Last>
Chris@16:         struct distance :
Chris@16:             distance_detail::linear_distance<First, Last>
Chris@16:         {};
Chris@16:     };
Chris@16: }}
Chris@16: 
Chris@101: #ifdef BOOST_FUSION_WORKAROUND_FOR_LWG_2408
Chris@101: namespace std
Chris@101: {
Chris@101:     template <typename Derived, typename Category>
Chris@101:     struct iterator_traits< ::boost::fusion::iterator_facade<Derived, Category> >
Chris@101:     { };
Chris@101: }
Chris@16: #endif
Chris@101: 
Chris@101: #endif