1 /*============================================================================= 2 Copyright (c) 2001-2011 Joel de Guzman 3 Copyright (c) 2006 Dan Marsden 4 5 Distributed under the Boost Software License, Version 1.0. (See accompanying 6 file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) 7 ==============================================================================*/ 8 #if !defined(BOOST_FUSION_DISTANCE_IMPL_20060223_0814) 9 #define BOOST_FUSION_DISTANCE_IMPL_20060223_0814 10 11 #include <boost/mpl/minus.hpp> 12 13 namespace example 14 { 15 struct example_struct_iterator_tag; 16 } 17 18 namespace boost { namespace fusion { 19 20 namespace extension 21 { 22 template<typename Tag> 23 struct distance_impl; 24 25 template<> 26 struct distance_impl<example::example_struct_iterator_tag> 27 { 28 template<typename First, typename Last> 29 struct apply 30 : mpl::minus<typename Last::index, typename First::index> 31 { 32 typedef apply<First, Last> self; 33 34 static typename self::type callboost::fusion::extension::distance_impl::apply35 call(First const& first, Last const& last) 36 { 37 return typename self::type(); 38 } 39 }; 40 }; 41 } 42 }} 43 44 #endif 45