as_matcher.hpp 1.5 KB

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  1. ///////////////////////////////////////////////////////////////////////////////
  2. // as_matcher.hpp
  3. //
  4. // Copyright 2008 Eric Niebler. Distributed under the Boost
  5. // Software License, Version 1.0. (See accompanying file
  6. // LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
  7. #ifndef BOOST_XPRESSIVE_DETAIL_STATIC_TRANSFORMS_AS_MATCHER_HPP_EAN_04_01_2007
  8. #define BOOST_XPRESSIVE_DETAIL_STATIC_TRANSFORMS_AS_MATCHER_HPP_EAN_04_01_2007
  9. // MS compatible compilers support #pragma once
  10. #if defined(_MSC_VER)
  11. # pragma once
  12. #endif
  13. #include <boost/mpl/assert.hpp>
  14. #include <boost/xpressive/detail/detail_fwd.hpp>
  15. #include <boost/xpressive/detail/static/static.hpp>
  16. namespace boost { namespace xpressive { namespace grammar_detail
  17. {
  18. struct as_matcher : proto::transform<as_matcher>
  19. {
  20. template<typename Expr, typename State, typename Data>
  21. struct impl : proto::transform_impl<Expr, State, Data>
  22. {
  23. typedef typename impl::data data_type;
  24. typedef
  25. typename data_type::template apply<
  26. typename proto::result_of::value<typename impl::expr>::type
  27. >::type
  28. result_type;
  29. result_type operator ()(
  30. typename impl::expr_param expr
  31. , typename impl::state_param
  32. , typename impl::data_param data
  33. ) const
  34. {
  35. return data.call(proto::value(expr));
  36. }
  37. };
  38. };
  39. }}}
  40. #endif