distance_impl.hpp 1.4 KB

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  1. /*=============================================================================
  2. Copyright (c) 2009 Hartmut Kaiser
  3. Distributed under the Boost Software License, Version 1.0. (See accompanying
  4. file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
  5. ==============================================================================*/
  6. #if !defined(BOOST_FUSION_NVIEW_DISTANCE_IMPL_SEP_23_2009_0328PM)
  7. #define BOOST_FUSION_NVIEW_DISTANCE_IMPL_SEP_23_2009_0328PM
  8. #include <boost/fusion/support/config.hpp>
  9. #include <boost/fusion/iterator/distance.hpp>
  10. namespace boost { namespace fusion
  11. {
  12. struct nview_iterator_tag;
  13. namespace extension
  14. {
  15. template<typename Tag>
  16. struct distance_impl;
  17. template<>
  18. struct distance_impl<nview_iterator_tag>
  19. {
  20. template<typename First, typename Last>
  21. struct apply
  22. : result_of::distance<typename First::first_type, typename Last::first_type>
  23. {
  24. typedef typename result_of::distance<
  25. typename First::first_type, typename Last::first_type
  26. >::type type;
  27. BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
  28. static type
  29. call(First const& /*first*/, Last const& /*last*/)
  30. {
  31. return type();
  32. }
  33. };
  34. };
  35. }
  36. }}
  37. #endif