text: /*=============================================================================
      Copyright (c) 2011 Eric Niebler
  
      Distributed under the Boost Software License, Version 1.0. (See accompanying
      file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
  ==============================================================================*/
  
  #if !defined(QSBOOST_FUSION_SINGLE_VIEW_DISTANCE_IMPL_JUL_07_2011_1348PM)
  #define QSBOOST_FUSION_SINGLE_VIEW_DISTANCE_IMPL_JUL_07_2011_1348PM
  
  #include <qsboost/fusion/support/config.hpp>
  #include <qsboost/mpl/minus.hpp>
  
  namespace qsboost { namespace fusion 
  {
      struct single_view_iterator_tag;
  
      namespace extension
      {
          template<typename Tag>
          struct distance_impl;
  
          template<>
          struct distance_impl<single_view_iterator_tag>
          {
              template<typename First, typename Last>
              struct apply
                : mpl::minus<typename Last::position, typename First::position>
              {
                  typedef typename mpl::minus<typename Last::position,
                      typename First::position>::type type;
  
                  QSBOOST_CONSTEXPR QSBOOST_FUSION_GPU_ENABLED
                  static type
                  call(First const& /*first*/, Last const& /*last*/)
                  {
                      return type();
                  }
              };
          };
      }
  
  }}
  
  #endif
  