Chris@16: /*=============================================================================
Chris@16:     Copyright (c) 2007 Tobias Schwinger
Chris@16:   
Chris@16:     Use modification and distribution are subject to the Boost Software 
Chris@16:     License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
Chris@16:     http://www.boost.org/LICENSE_1_0.txt).
Chris@16: ==============================================================================*/
Chris@16: 
Chris@16: #ifndef BOOST_FUNCTIONAL_LIGHTWEIGHT_FORWARD_ADAPTER_HPP_INCLUDED
Chris@16: #   ifndef BOOST_PP_IS_ITERATING
Chris@16: 
Chris@16: #   include <boost/config.hpp>
Chris@16: #   include <boost/detail/workaround.hpp>
Chris@16: 
Chris@16: #   include <boost/preprocessor/cat.hpp>
Chris@16: #   include <boost/preprocessor/iteration/iterate.hpp>
Chris@16: #   include <boost/preprocessor/repetition/enum.hpp>
Chris@16: #   include <boost/preprocessor/repetition/enum_params.hpp>
Chris@16: #   include <boost/preprocessor/repetition/enum_binary_params.hpp>
Chris@16: #   include <boost/preprocessor/facilities/intercept.hpp>
Chris@16: 
Chris@16: #   include <boost/utility/result_of.hpp>
Chris@16: #   include <boost/ref.hpp>
Chris@16: 
Chris@16: #   ifndef BOOST_FUNCTIONAL_LIGHTWEIGHT_FORWARD_ADAPTER_MAX_ARITY
Chris@16: #     define BOOST_FUNCTIONAL_LIGHTWEIGHT_FORWARD_ADAPTER_MAX_ARITY 10
Chris@16: #   elif BOOST_FUNCTIONAL_FORDWARD_ADAPTER_MAX_ARITY < 3
Chris@16: #     undef  BOOST_FUNCTIONAL_LIGHTWEIGHT_FORWARD_ADAPTER_MAX_ARITY
Chris@16: #     define BOOST_FUNCTIONAL_LIGHTWEIGHT_FORWARD_ADAPTER_MAX_ARITY 3
Chris@16: #   endif
Chris@16: 
Chris@16: namespace boost 
Chris@16: {
Chris@16:     template< typename Function, int Arity_Or_MinArity = -1, int MaxArity = -1 >
Chris@16:     class lightweight_forward_adapter;
Chris@16: 
Chris@16:     //----- ---- --- -- - -  -   -
Chris@16: 
Chris@16:     namespace detail
Chris@16:     {
Chris@16:         template< class MostDerived, typename Function, typename FunctionConst, 
Chris@16:             int Arity, int MinArity >
Chris@16:         struct lightweight_forward_adapter_impl;
Chris@16: 
Chris@16:         struct lightweight_forward_adapter_result
Chris@16:         {
Chris@16:             template< typename Sig > struct apply;
Chris@16: 
Chris@16:             // Utility metafunction for argument transform
Chris@16:             template< typename T > struct x  { typedef T const& t; };
Chris@16:             template< typename T > struct x< boost::reference_wrapper<T> >
Chris@16:             { typedef T& t; };
Chris@16:             template< typename T > struct x<T&>       : x<T> { };
Chris@16:             template< typename T > struct x<T const&> : x<T> { };
Chris@16:             template< typename T > struct x<T const>  : x<T> { };
Chris@16: 
Chris@16:             // Utility metafunction to choose target function qualification
Chris@16:             template< typename T > struct c
Chris@16:             { typedef typename T::target_function_t t; };
Chris@16:             template< typename T > struct c<T&      >
Chris@16:             { typedef typename T::target_function_t t; };
Chris@16:             template< typename T > struct c<T const >
Chris@16:             { typedef typename T::target_function_const_t t; };
Chris@16:             template< typename T > struct c<T const&>
Chris@16:             { typedef typename T::target_function_const_t t; };
Chris@16:         };
Chris@16:     }
Chris@16: 
Chris@16: #   define BOOST_TMP_MACRO(f,fn,fc) \
Chris@16:         boost::detail::lightweight_forward_adapter_impl< \
Chris@16:             lightweight_forward_adapter<f,Arity_Or_MinArity,MaxArity>, fn, fc, \
Chris@16:             (MaxArity!=-1? MaxArity :Arity_Or_MinArity!=-1? Arity_Or_MinArity \
Chris@16:                 :BOOST_FUNCTIONAL_LIGHTWEIGHT_FORWARD_ADAPTER_MAX_ARITY), \
Chris@16:             (Arity_Or_MinArity!=-1? Arity_Or_MinArity : 0) >
Chris@16: 
Chris@16:     template< typename Function, int Arity_Or_MinArity, int MaxArity >
Chris@16:     class lightweight_forward_adapter
Chris@16:         : public BOOST_TMP_MACRO(Function,Function,Function const)
Chris@16:         , private Function
Chris@16:     {
Chris@16:       public:
Chris@16:         lightweight_forward_adapter(Function const& f = Function()) 
Chris@16:           : Function(f) 
Chris@16:         { }
Chris@16: 
Chris@16:         typedef Function        target_function_t;
Chris@16:         typedef Function const  target_function_const_t;
Chris@16: 
Chris@16:         Function       & target_function()       { return *this; }
Chris@16:         Function const & target_function() const { return *this; }
Chris@16: 
Chris@16:         template< typename Sig > struct result
Chris@16:             : detail::lightweight_forward_adapter_result::template apply<Sig>
Chris@16:         { };
Chris@16: 
Chris@16:         using BOOST_TMP_MACRO(Function,Function, Function const)::operator();
Chris@16:     };
Chris@16:     template< typename Function, int Arity_Or_MinArity, int MaxArity >
Chris@16:     class lightweight_forward_adapter< Function const, Arity_Or_MinArity, 
Chris@16:         MaxArity >
Chris@16:         : public BOOST_TMP_MACRO(Function const, Function const, Function const)
Chris@16:         , private Function
Chris@16:     {
Chris@16:       public:
Chris@16:         lightweight_forward_adapter(Function const& f = Function())
Chris@16:           : Function(f) 
Chris@16:         { }
Chris@16: 
Chris@16:         typedef Function const target_function_t;
Chris@16:         typedef Function const target_function_const_t;
Chris@16: 
Chris@16:         Function const & target_function() const { return *this; }
Chris@16: 
Chris@16:         template< typename Sig > struct result
Chris@16:             : detail::lightweight_forward_adapter_result::template apply<Sig>
Chris@16:         { };
Chris@16: 
Chris@16:         using BOOST_TMP_MACRO(Function const,Function const, Function const)
Chris@16:             ::operator();
Chris@16:     };
Chris@16:     template< typename Function, int Arity_Or_MinArity, int MaxArity >
Chris@16:     class lightweight_forward_adapter< Function &, Arity_Or_MinArity, MaxArity >
Chris@16:         : public BOOST_TMP_MACRO(Function&, Function, Function)
Chris@16:     {
Chris@16:         Function& ref_function;
Chris@16:       public:
Chris@16:         lightweight_forward_adapter(Function& f)
Chris@16:           : ref_function(f) 
Chris@16:         { }
Chris@16: 
Chris@16:         typedef Function target_function_t;
Chris@16:         typedef Function target_function_const_t;
Chris@16: 
Chris@16:         Function & target_function() const { return this->ref_function; }
Chris@16: 
Chris@16:         template< typename Sig > struct result
Chris@16:             : detail::lightweight_forward_adapter_result::template apply<Sig>
Chris@16:         { };
Chris@16: 
Chris@16:         using BOOST_TMP_MACRO(Function&, Function, Function)::operator();
Chris@16:     }; 
Chris@16: 
Chris@16:     #undef BOOST_TMP_MACRO
Chris@16: 
Chris@16:     namespace detail
Chris@16:     {
Chris@16:         template< class Self >
Chris@16:         struct lightweight_forward_adapter_result::apply< Self() >
Chris@16:             : boost::result_of< BOOST_DEDUCED_TYPENAME c<Self>::t() >
Chris@16:         { };
Chris@16: 
Chris@16:         template< class MD, class F, class FC >
Chris@16:         struct lightweight_forward_adapter_impl<MD,F,FC,0,0>
Chris@16:             : lightweight_forward_adapter_result
Chris@16:         {
Chris@16:             inline typename boost::result_of< FC() >::type
Chris@16:             operator()() const
Chris@16:             {
Chris@16:                 return static_cast<MD const*>(this)->target_function()();
Chris@16:             }
Chris@16: 
Chris@16:             inline typename boost::result_of< F() >::type
Chris@16:             operator()()
Chris@16:             {
Chris@16:                 return static_cast<MD*>(this)->target_function()();
Chris@16:             }
Chris@16:         };
Chris@16: 
Chris@16: #       define  BOOST_PP_FILENAME_1 \
Chris@16:             <boost/functional/lightweight_forward_adapter.hpp>
Chris@16: #       define  BOOST_PP_ITERATION_LIMITS                                     \
Chris@16:             (1,BOOST_FUNCTIONAL_LIGHTWEIGHT_FORWARD_ADAPTER_MAX_ARITY) 
Chris@16: #       include BOOST_PP_ITERATE()
Chris@16: 
Chris@16:     } // namespace detail
Chris@16: 
Chris@16:     template<class F, int A0, int A1>
Chris@16:     struct result_of<boost::lightweight_forward_adapter<F,A0,A1> const ()>
Chris@16:         : boost::detail::lightweight_forward_adapter_result::template apply<
Chris@16:             boost::lightweight_forward_adapter<F,A0,A1> const () >
Chris@16:     { };
Chris@16:     template<class F, int A0, int A1>
Chris@16:     struct result_of<boost::lightweight_forward_adapter<F,A0,A1>()>
Chris@16:         : boost::detail::lightweight_forward_adapter_result::template apply<
Chris@16:             boost::lightweight_forward_adapter<F,A0,A1>() >
Chris@16:     { };
Chris@16:     template<class F, int A0, int A1>
Chris@16:     struct result_of<boost::lightweight_forward_adapter<F,A0,A1> const& ()>
Chris@16:         : boost::detail::lightweight_forward_adapter_result::template apply<
Chris@16:             boost::lightweight_forward_adapter<F,A0,A1> const () >
Chris@16:     { };
Chris@16:     template<class F, int A0, int A1>
Chris@16:     struct result_of<boost::lightweight_forward_adapter<F,A0,A1>& ()>
Chris@16:         : boost::detail::lightweight_forward_adapter_result::template apply<
Chris@16:             boost::lightweight_forward_adapter<F,A0,A1>() >
Chris@16:     { };
Chris@16: }
Chris@16: 
Chris@16: #     define BOOST_FUNCTIONAL_LIGHTWEIGHT_FORWARD_ADAPTER_HPP_INCLUDED
Chris@16: 
Chris@16: #   else // defined(BOOST_PP_IS_ITERATING)
Chris@16: #     define N BOOST_PP_ITERATION() 
Chris@16: 
Chris@16:         template< class Self, BOOST_PP_ENUM_PARAMS(N,typename T) >
Chris@16:         struct lightweight_forward_adapter_result::apply<
Chris@16:             Self (BOOST_PP_ENUM_PARAMS(N,T)) >
Chris@16:             : boost::result_of<
Chris@16:                 BOOST_DEDUCED_TYPENAME c<Self>::t (BOOST_PP_ENUM_BINARY_PARAMS(N,
Chris@16:                     typename x<T,>::t BOOST_PP_INTERCEPT)) >
Chris@16:         { };
Chris@16: 
Chris@16:         template< class MD, class F, class FC >
Chris@16:         struct lightweight_forward_adapter_impl<MD,F,FC,BOOST_PP_DEC(N),N>
Chris@16:             : lightweight_forward_adapter_result
Chris@16:         {
Chris@16:             template< BOOST_PP_ENUM_PARAMS(N,typename T) >
Chris@16:             inline typename boost::result_of< F(BOOST_PP_ENUM_BINARY_PARAMS(N,
Chris@16:                 T,const& BOOST_PP_INTERCEPT)) >::type
Chris@16:             operator()(BOOST_PP_ENUM_BINARY_PARAMS(N,T,& BOOST_PP_INTERCEPT));
Chris@16:         };
Chris@16: 
Chris@16:         template< class MD, class F, class FC, int MinArity >
Chris@16:         struct lightweight_forward_adapter_impl<MD,F,FC,N,MinArity>
Chris@16:             : lightweight_forward_adapter_impl<MD,F,FC,BOOST_PP_DEC(N),MinArity>
Chris@16:         {
Chris@16:             using lightweight_forward_adapter_impl<MD,F,FC,BOOST_PP_DEC(N),
Chris@16:                 MinArity>::operator();
Chris@16: 
Chris@16: #     define M(z,i,d) \
Chris@16:           static_cast<typename d::template x<T##i>::t>(a##i)
Chris@16: 
Chris@16:             template< BOOST_PP_ENUM_PARAMS(N,typename T) >
Chris@16:             inline typename lightweight_forward_adapter_result::template apply<
Chris@16:                 MD const (BOOST_PP_ENUM_BINARY_PARAMS(N,
Chris@16:                     T,const& BOOST_PP_INTERCEPT)) >::type
Chris@16:             operator()(BOOST_PP_ENUM_BINARY_PARAMS(N,T,const& a)) const
Chris@16:             {
Chris@16:                 typedef lightweight_forward_adapter_result _;
Chris@16:                 return static_cast<MD const*>(this)->target_function()(
Chris@16:                     BOOST_PP_ENUM(N,M,_));
Chris@16:             }
Chris@16:             template< BOOST_PP_ENUM_PARAMS(N,typename T) >
Chris@16:             inline typename lightweight_forward_adapter_result::template apply<
Chris@16:                 MD (BOOST_PP_ENUM_BINARY_PARAMS(N,
Chris@16:                     T,const& BOOST_PP_INTERCEPT)) >::type
Chris@16:             operator()(BOOST_PP_ENUM_BINARY_PARAMS(N,T,const& a))
Chris@16:             {
Chris@16:                 typedef lightweight_forward_adapter_result _;
Chris@16:                 return static_cast<MD*>(this)->target_function()(
Chris@16:                     BOOST_PP_ENUM(N,M,_));
Chris@16:             }
Chris@16: #     undef M
Chris@16:       };
Chris@16: 
Chris@16: #     undef N
Chris@16: #   endif // defined(BOOST_PP_IS_ITERATING)
Chris@16: 
Chris@16: #endif // include guard
Chris@16: