text: /*=============================================================================
      Copyright (c) 2005-2006 Joao Abecasis
      Copyright (c) 2006-2007 Tobias Schwinger
  
      Use modification and distribution are subject to 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).
  ==============================================================================*/
  
  #if !defined(BOOST_FUSION_FUNCTIONAL_INVOCATION_INVOKE_HPP_INCLUDED)
  #if !defined(BOOST_PP_IS_ITERATING)
  
  #include <boost/preprocessor/cat.hpp>
  #include <boost/preprocessor/iteration/iterate.hpp>
  #include <boost/preprocessor/arithmetic/dec.hpp>
  #include <boost/preprocessor/repetition/repeat_from_to.hpp>
  #include <boost/preprocessor/repetition/enum.hpp>
  #include <boost/preprocessor/repetition/enum_shifted.hpp>
  #include <boost/preprocessor/repetition/enum_params.hpp>
  #include <boost/preprocessor/repetition/enum_shifted_params.hpp>
  
  #include <boost/mpl/if.hpp>
  #include <boost/mpl/eval_if.hpp>
  #include <boost/mpl/or.hpp>
  #include <boost/mpl/front.hpp>
  #include <boost/mpl/identity.hpp>
  
  #include <boost/type_traits/add_const.hpp>
  #include <boost/type_traits/remove_cv.hpp>
  #include <boost/type_traits/add_reference.hpp>
  #include <boost/type_traits/remove_reference.hpp>
  #include <boost/type_traits/is_convertible.hpp>
  
  #include <boost/function_types/is_function.hpp>
  #include <boost/function_types/is_callable_builtin.hpp>
  #include <boost/function_types/is_member_pointer.hpp>
  #include <boost/function_types/is_member_function_pointer.hpp>
  #include <boost/function_types/result_type.hpp>
  #include <boost/function_types/parameter_types.hpp>
  
  #include <boost/utility/result_of.hpp>
  
  #include <boost/fusion/support/category_of.hpp>
  #include <boost/fusion/sequence/intrinsic/at.hpp>
  #include <boost/fusion/sequence/intrinsic/size.hpp>
  #include <boost/fusion/sequence/intrinsic/front.hpp>
  #include <boost/fusion/sequence/intrinsic/begin.hpp>
  #include <boost/fusion/iterator/next.hpp>
  #include <boost/fusion/iterator/deref.hpp>
  #include <boost/fusion/functional/invocation/limits.hpp>
  #include <boost/fusion/functional/invocation/detail/that_ptr.hpp>
  
  namespace boost { namespace fusion
  {
      namespace result_of
      {
          template <typename Function, class Sequence> struct invoke;
      }
  
      //~ template <typename Function, class Sequence>
      //~ inline typename result_of::invoke<Function, Sequence>::type
      //~ invoke(Function, Sequence &);
  
      //~ template <typename Function, class Sequence>
      //~ inline typename result_of::invoke<Function, Sequence const>::type
      //~ invoke(Function, Sequence const &);
  
      //----- ---- --- -- - -  -   -
  
      namespace detail
      {
          namespace ft = function_types;
  
          template<
              typename Function, class Sequence,
              int N = result_of::size<Sequence>::value,
              bool CBI = ft::is_callable_builtin<Function>::value,
              bool RandomAccess = traits::is_random_access<Sequence>::value
              >
          struct invoke_impl;
  
          template <class Sequence, int N>
          struct invoke_param_types;
  
          template <typename T, class Sequence>
          struct invoke_data_member;
  
          template <typename Function, class Sequence, int N, bool RandomAccess>
          struct invoke_fn_ptr;
  
          template <typename Function, class Sequence, int N, bool RandomAccess>
          struct invoke_mem_fn;
  
          #define  BOOST_PP_FILENAME_1 <boost/fusion/functional/invocation/invoke.hpp>
          #define  BOOST_PP_ITERATION_LIMITS (0, BOOST_FUSION_INVOKE_MAX_ARITY)
          #include BOOST_PP_ITERATE()
  
          template <typename F, class Sequence, int N, bool RandomAccess>
          struct invoke_nonmember_builtin
          // use same implementation as for function objects but...
              : invoke_fn_ptr< // ...work around boost::result_of bugs
                  typename mpl::eval_if< ft::is_function<F>,
                      boost::add_reference<F>, boost::remove_cv<F> >::type,
                  Sequence, N, RandomAccess >
          { };
  
          template <typename Function, class Sequence, int N, bool RandomAccess>
          struct invoke_impl<Function,Sequence,N,true,RandomAccess>
              : mpl::if_< ft::is_member_function_pointer<Function>,
                  invoke_mem_fn<Function,Sequence,N,RandomAccess>,
                  invoke_nonmember_builtin<Function,Sequence,N,RandomAccess>
              >::type
          { };
  
          template <typename Function, class Sequence, bool RandomAccess>
          struct invoke_impl<Function,Sequence,1,true,RandomAccess>
              : mpl::eval_if< ft::is_member_pointer<Function>,
                  mpl::if_< ft::is_member_function_pointer<Function>,
                      invoke_mem_fn<Function,Sequence,1,RandomAccess>,
                      invoke_data_member<Function, Sequence> >,
                  mpl::identity< invoke_nonmember_builtin<
                      Function,Sequence,1,RandomAccess> >
              >::type
          { };
  
          template <typename T, class C, class Sequence>
          struct invoke_data_member< T C::*, Sequence >
          {
          private:
  
              typedef typename result_of::front<Sequence>::type that;
  
              typedef mpl::or_< boost::is_convertible<that,C*>,
                                boost::is_convertible<that,C&>,
                                non_const_pointee<that> > non_const_cond;
  
              typedef typename mpl::eval_if< non_const_cond,
                  mpl::identity<C>, add_const<C> >::type qualified_class;
  
              typedef typename mpl::eval_if< non_const_cond,
                  mpl::identity<T>, add_const<T> >::type qualified_type;
  
          public:
  
              typedef typename boost::add_reference<qualified_type>::type
                  result_type;
  
              BOOST_FUSION_GPU_ENABLED
              static inline result_type call(T C::* f, Sequence & s)
              {
                  typename result_of::front<Sequence>::type c = fusion::front(s);
                  return that_ptr<qualified_class>::get(c)->*f;
              }
          };
      }
  
      namespace result_of
      {
          template <typename Function, class Sequence> struct invoke
          {
              typedef typename detail::invoke_impl<
                  typename boost::remove_reference<Function>::type, Sequence
                >::result_type type;
          };
      }
  
      template <typename Function, class Sequence>
      BOOST_FUSION_GPU_ENABLED
      inline typename result_of::invoke<Function,Sequence>::type
      invoke(Function f, Sequence & s)
      {
          return detail::invoke_impl<
                  typename boost::remove_reference<Function>::type,Sequence
              >::call(f,s);
      }
  
      template <typename Function, class Sequence>
      BOOST_FUSION_GPU_ENABLED
      inline typename result_of::invoke<Function,Sequence const>::type
      invoke(Function f, Sequence const & s)
      {
          return detail::invoke_impl<
                  typename boost::remove_reference<Function>::type,Sequence const
              >::call(f,s);
      }
  
  }}
  
  #define BOOST_FUSION_FUNCTIONAL_INVOCATION_INVOKE_HPP_INCLUDED
  #else // defined(BOOST_PP_IS_ITERATING)
  ///////////////////////////////////////////////////////////////////////////////
  //
  //  Preprocessor vertical repetition code
  //
  ///////////////////////////////////////////////////////////////////////////////
  #define N BOOST_PP_ITERATION()
  
          template <typename Function, class Sequence>
          struct invoke_impl<Function,Sequence,N,false,true>
          {
          public:
  
              typedef typename boost::result_of<
  #define M(z,j,data) typename result_of::at_c<Sequence,j>::type
                      Function(BOOST_PP_ENUM(N,M,~)) >::type result_type;
  #undef M
  
  #if N > 0
  
              template <typename F>
              BOOST_FUSION_GPU_ENABLED
              static inline result_type
              call(F & f, Sequence & s)
              {
  #define M(z,j,data) fusion::at_c<j>(s)
                  return f( BOOST_PP_ENUM(N,M,~) );
              }
  
  #else
              template <typename F>
              BOOST_FUSION_GPU_ENABLED
              static inline result_type
              call(F & f, Sequence & /*s*/)
              {
                  return f();
              }
  
  #endif
  
          };
  
          template <typename Function, class Sequence>
          struct invoke_fn_ptr<Function,Sequence,N,true>
          {
          public:
  
              typedef typename ft::result_type<Function>::type result_type;
  
  #if N > 0
  
              template <typename F>
              BOOST_FUSION_GPU_ENABLED
              static inline result_type
              call(F & f, Sequence & s)
              {
  #define M(z,j,data) fusion::at_c<j>(s)
                  return f( BOOST_PP_ENUM(N,M,~) );
              }
  
  #else
              template <typename F>
              BOOST_FUSION_GPU_ENABLED
              static inline result_type
              call(F & f, Sequence & /*s*/)
              {
                  return f();
              }
  
  #endif
  
          };
  
  
  #if N > 0
          template <typename Function, class Sequence>
          struct invoke_mem_fn<Function,Sequence,N,true>
          {
          public:
  
              typedef typename ft::result_type<Function>::type result_type;
  
              template <typename F>
              BOOST_FUSION_GPU_ENABLED
              static inline result_type
              call(F & f, Sequence & s)
              {
                  return (that_ptr<typename mpl::front<
                                  ft::parameter_types<Function> >::type
                      >::get(fusion::at_c<0>(s))->*f)(BOOST_PP_ENUM_SHIFTED(N,M,~));
              }
          };
  #endif
  
  #undef M
  
  #define M(z,j,data)                                                             \
              typename seq::I##j i##j =                                          \
                  fusion::next(BOOST_PP_CAT(i,BOOST_PP_DEC(j)));
  
          template <typename Function, class Sequence>
          struct invoke_impl<Function,Sequence,N,false,false>
          {
          private:
              typedef invoke_param_types<Sequence,N> seq;
          public:
  
              typedef typename boost::result_of<
                  Function(BOOST_PP_ENUM_PARAMS(N,typename seq::T))
                  >::type result_type;
  
  #if N > 0
  
              template <typename F>
              BOOST_FUSION_GPU_ENABLED
              static inline result_type
              call(F & f, Sequence & s)
              {
                  typename seq::I0 i0 = fusion::begin(s);
                  BOOST_PP_REPEAT_FROM_TO(1,N,M,~)
                  return f( BOOST_PP_ENUM_PARAMS(N,*i) );
              }
  
  #else
  
              template <typename F>
              BOOST_FUSION_GPU_ENABLED
              static inline result_type
              call(F & f, Sequence & /*s*/)
              {
                  return f();
              }
  
  #endif
  
          };
  
          template <typename Function, class Sequence>
          struct invoke_fn_ptr<Function,Sequence,N,false>
          {
          private:
              typedef invoke_param_types<Sequence,N> seq;
          public:
  
              typedef typename ft::result_type<Function>::type result_type;
  
  #if N > 0
  
              template <typename F>
              BOOST_FUSION_GPU_ENABLED
              static inline result_type
              call(F & f, Sequence & s)
              {
                  typename seq::I0 i0 = fusion::begin(s);
                  BOOST_PP_REPEAT_FROM_TO(1,N,M,~)
                  return f( BOOST_PP_ENUM_PARAMS(N,*i) );
              }
  
  #else
  
              template <typename F>
              BOOST_FUSION_GPU_ENABLED
              static inline result_type
              call(F & f, Sequence & /*s*/)
              {
                  return f();
              }
  
  #endif
  
          };
  
  #if N > 0
          template <typename Function, class Sequence>
          struct invoke_mem_fn<Function,Sequence,N,false>
          {
          private:
              typedef invoke_param_types<Sequence,N> seq;
          public:
  
              typedef typename ft::result_type<Function>::type result_type;
  
              template <typename F>
              BOOST_FUSION_GPU_ENABLED
              static inline result_type
              call(F & f, Sequence & s)
              {
                  typename seq::I0 i0 = fusion::begin(s);
                  BOOST_PP_REPEAT_FROM_TO(1,N,M,~)
  
                  return (that_ptr< typename mpl::front<
                                        ft::parameter_types<Function> >::type
                      >::get(*i0)->*f)(BOOST_PP_ENUM_SHIFTED_PARAMS(N,*i));
              }
          };
  #endif
  
  #undef M
  
          template <class Sequence> struct invoke_param_types<Sequence,N>
          {
  #if N > 0
              typedef typename result_of::begin<Sequence>::type I0;
              typedef typename result_of::deref<I0>::type T0;
  
  #define M(z,i,data)                                                             \
              typedef typename result_of::next<                                  \
                  BOOST_PP_CAT(I,BOOST_PP_DEC(i))>::type I##i;                   \
              typedef typename result_of::deref<I##i>::type T##i;
  
              BOOST_PP_REPEAT_FROM_TO(1,N,M,~)
  #undef M
  #endif
          };
  
  
  #undef N
  #endif // defined(BOOST_PP_IS_ITERATING)
  #endif
  
  