at_impl.hpp 929 B

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  1. #ifndef BOOST_MPL_SET_AUX_AT_IMPL_HPP_INCLUDED
  2. #define BOOST_MPL_SET_AUX_AT_IMPL_HPP_INCLUDED
  3. // Copyright Aleksey Gurtovoy 2003-2004
  4. //
  5. // Distributed under the Boost Software License, Version 1.0.
  6. // (See accompanying file LICENSE_1_0.txt or copy at
  7. // http://www.boost.org/LICENSE_1_0.txt)
  8. //
  9. // See http://www.boost.org/libs/mpl for documentation.
  10. // $Id$
  11. // $Date$
  12. // $Revision$
  13. #include <boost/mpl/at_fwd.hpp>
  14. #include <boost/mpl/set/aux_/has_key_impl.hpp>
  15. #include <boost/mpl/set/aux_/tag.hpp>
  16. #include <boost/mpl/if.hpp>
  17. #include <boost/mpl/void.hpp>
  18. namespace boost { namespace mpl {
  19. template<>
  20. struct at_impl< aux::set_tag >
  21. {
  22. template< typename Set, typename T > struct apply
  23. {
  24. typedef typename if_<
  25. has_key_impl<aux::set_tag>::apply<Set,T>
  26. , T
  27. , void_
  28. >::type type;
  29. };
  30. };
  31. }}
  32. #endif // BOOST_MPL_SET_AUX_AT_IMPL_HPP_INCLUDED