text: // Boost.TypeErasure library
  //
  // Copyright 2011 Steven Watanabe
  //
  // 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)
  //
  // $Id$
  
  #if !defined(BOOST_PP_IS_ITERATING)
  
  #ifndef BOOST_TYPE_ERASURE_CHECK_MATCH_HPP_INCLUDED
  #define BOOST_TYPE_ERASURE_CHECK_MATCH_HPP_INCLUDED
  
  #include <boost/mpl/vector.hpp>
  #include <boost/mpl/bool.hpp>
  #include <boost/mpl/is_sequence.hpp>
  #include <boost/mpl/find_if.hpp>
  #include <boost/mpl/not.hpp>
  #include <boost/mpl/end.hpp>
  #include <boost/type_traits/is_same.hpp>
  #include <boost/preprocessor/cat.hpp>
  #include <boost/preprocessor/iteration/iterate.hpp>
  #include <boost/preprocessor/repetition/repeat.hpp>
  #include <boost/preprocessor/repetition/enum_params.hpp>
  #include <boost/preprocessor/repetition/enum_trailing_params.hpp>
  #include <boost/preprocessor/repetition/enum_trailing_binary_params.hpp>
  #include <boost/type_erasure/detail/extract_concept.hpp>
  #include <boost/type_erasure/relaxed.hpp>
  #include <boost/type_erasure/detail/access.hpp>
  
  namespace boost {
  namespace type_erasure {
  
  template<class T>
  struct typeid_;
  
  template<class Concept>
  class binding;
  
  namespace detail {
  
  template<class P, class T, class Table>
  bool maybe_check_table(const T& arg, const Table*& table, boost::mpl::true_)
  {
      if(table == 0) {
          table = &::boost::type_erasure::detail::access::table(arg);
          return true;
      } else {
          return table->template find< ::boost::type_erasure::typeid_<P> >()() ==
              ::boost::type_erasure::detail::access::table(arg).
                  template find< ::boost::type_erasure::typeid_<P> >()();
      }
  }
  
  template<class P, class T, class Table>
  bool maybe_check_table(const T&, const Table*&, boost::mpl::false_)
  {
      return true;
  }
  
  template<class Concept, class T>
  struct should_check :
      boost::mpl::and_<
          ::boost::type_erasure::is_placeholder<T>,
          ::boost::type_erasure::is_relaxed<Concept>
      >
  {};
  
  }
  
  #ifdef BOOST_TYPE_ERASURE_DOXYGEN
  
  /**
   * If @ref relaxed is in @c Concept, checks whether the
   * arguments to @c f match the types specified by
   * @c binding.  If @ref relaxed is not in @c Concept,
   * returns true.  If @c binding is not specified, it will
   * be deduced from the arguments.
   */
  template<class Concept, class Op, class... U>
  bool check_match(const binding<Concept>& binding_arg, const Op& f, U&&... args);
  
  /**
   * \overload
   */
  template<class Op, class... U>
  bool check_match(const Op& f, U&&... args);
  
  #else
  
  #if !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES) && !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
  
  namespace detail {
  
  template<class Concept>
  bool check_table(const ::boost::type_erasure::binding<Concept>* t, void(*)())
  {
      return true;
  }
  
  template<class Concept, class R, class T0, class... T, class U0, class... U>
  bool check_table(
      const ::boost::type_erasure::binding<Concept>* t,
      R(*)(T0, T...),
      const U0& arg0,
      const U&... arg)
  {
      typedef typename ::boost::remove_cv<
          typename ::boost::remove_reference<T0>::type
      >::type t0;
      if(!::boost::type_erasure::detail::maybe_check_table<t0>(
          arg0,
          t,
          ::boost::type_erasure::detail::should_check<Concept, t0>()))
          return false;
  
      return check_table(t, static_cast<void(*)(T...)>(0), arg...);
  }
  
  }
  
  template<class Concept, class Op, class... U>
  bool check_match(
      const ::boost::type_erasure::binding<Concept>& table,
      const Op&,
      U&&... arg)
  {
  
      return ::boost::type_erasure::detail::check_table(
          &table,
          static_cast<typename ::boost::type_erasure::detail::get_signature<Op>::type*>(0),
          arg...);
  }
  
  template<
      class Op,
      class... U
  >
  bool check_match(
      const Op&,
      U&&... arg)
  {
      const ::boost::type_erasure::binding<
          typename ::boost::type_erasure::detail::extract_concept<
              typename ::boost::type_erasure::detail::get_signature<Op>::type, U...>::type>* p = 0;
  
      return ::boost::type_erasure::detail::check_table(
          p, static_cast<typename ::boost::type_erasure::detail::get_signature<Op>::type*>(0), arg...);
  }
  
  #else
  
  #define BOOST_PP_FILENAME_1 <boost/type_erasure/check_match.hpp>
  #define BOOST_PP_ITERATION_LIMITS (0, BOOST_TYPE_ERASURE_MAX_ARITY)
  #include BOOST_PP_ITERATE()
  
  #endif
  
  #endif
  
  }
  }
  
  #endif
  
  #else
  
  namespace detail {
  
  #define N BOOST_PP_ITERATION()
  
  #define BOOST_TYPE_ERASURE_CHECK_TABLE(z, n, data)                          \
      typedef typename ::boost::remove_cv<                                    \
          typename ::boost::remove_reference<BOOST_PP_CAT(T, n)>::type        \
      >::type BOOST_PP_CAT(t, n);                                             \
      if(!::boost::type_erasure::detail::maybe_check_table<BOOST_PP_CAT(t, n)>(   \
          BOOST_PP_CAT(arg, n),                                               \
          t,                                                                  \
          ::boost::type_erasure::detail::should_check<Concept, BOOST_PP_CAT(t, n)>())) \
          return false;
  
  template<
      class Concept,
      class R
      BOOST_PP_ENUM_TRAILING_PARAMS(N, class T)
      BOOST_PP_ENUM_TRAILING_PARAMS(N, class U)>
  bool
  BOOST_PP_CAT(check_table, N)(
      const ::boost::type_erasure::binding<Concept>* t,
      R (*)(BOOST_PP_ENUM_PARAMS(N, T))
      BOOST_PP_ENUM_TRAILING_BINARY_PARAMS(N, const U, &arg))
  {
      BOOST_PP_REPEAT(N, BOOST_TYPE_ERASURE_CHECK_TABLE, ~)
      return true;
  }
  
  #if N != 0
  
  template<class Sig BOOST_PP_ENUM_TRAILING_PARAMS(N, class U)>
  struct BOOST_PP_CAT(do_extract_concept, N);
  
  template<
      class R
      BOOST_PP_ENUM_TRAILING_PARAMS(N, class T)
      BOOST_PP_ENUM_TRAILING_PARAMS(N, class U)
  >
  struct BOOST_PP_CAT(do_extract_concept, N)<
      R(BOOST_PP_ENUM_PARAMS(N, T))
      BOOST_PP_ENUM_TRAILING_PARAMS(N, U)
  >
    : ::boost::type_erasure::detail::BOOST_PP_CAT(extract_concept, N)<
          BOOST_PP_ENUM_PARAMS(N, T)
          BOOST_PP_ENUM_TRAILING_PARAMS(N, U)>
  {};
  
  #endif
  
  }
  
  #ifdef BOOST_NO_CXX11_RVALUE_REFERENCES
  #define RREF &
  #else
  #define RREF &&
  #endif
  
  template<
      class Concept,
      class Op
      BOOST_PP_ENUM_TRAILING_PARAMS(N, class U)
  >
  bool check_match(
      const ::boost::type_erasure::binding<Concept>& table,
      const Op&
      BOOST_PP_ENUM_TRAILING_BINARY_PARAMS(N, U, RREF arg))
  {
  
      return ::boost::type_erasure::detail::BOOST_PP_CAT(check_table, N)(
          &table,
          (typename ::boost::type_erasure::detail::get_signature<Op>::type*)0
          BOOST_PP_ENUM_TRAILING_PARAMS(N, arg));
  }
  
  #if N != 0
  
  template<
      class Op
      BOOST_PP_ENUM_TRAILING_PARAMS(N, class U)
  >
  bool check_match(
      const Op&
      BOOST_PP_ENUM_TRAILING_BINARY_PARAMS(N, U, RREF arg))
  {
      const ::boost::type_erasure::binding<
          typename ::boost::type_erasure::detail::BOOST_PP_CAT(do_extract_concept, N)<
              typename ::boost::type_erasure::detail::get_signature<Op>::type,
              BOOST_PP_ENUM_PARAMS(N, U)>::type>* p = 0;
  
      return ::boost::type_erasure::detail::BOOST_PP_CAT(check_table, N)(
          p,
          (typename ::boost::type_erasure::detail::get_signature<Op>::type*)0
          BOOST_PP_ENUM_TRAILING_PARAMS(N, arg));
  }
  
  #undef RREF
  #undef BOOST_TYPE_ERASURE_CHECK_TABLE
  #undef N
  
  #endif
  
  #endif
  