front.hpp 945 B

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  1. /*=============================================================================
  2. Copyright (c) 2001-2011 Joel de Guzman
  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(FUSION_FRONT_10022005_1618)
  7. #define FUSION_FRONT_10022005_1618
  8. #include <boost/fusion/support/config.hpp>
  9. #include <boost/mpl/front.hpp>
  10. #include <boost/fusion/sequence/intrinsic/begin.hpp>
  11. #include <boost/fusion/iterator/value_of.hpp>
  12. namespace boost { namespace mpl
  13. {
  14. template <typename Tag>
  15. struct front_impl;
  16. template <>
  17. struct front_impl<fusion::fusion_sequence_tag>
  18. {
  19. template <typename Sequence>
  20. struct apply :
  21. fusion::result_of::value_of<typename fusion::result_of::begin<Sequence>::type> {};
  22. };
  23. }}
  24. #endif