Chris@16: /*
Chris@16:   Helper class used by variadic implementation of variadic boost::signals2::signal.
Chris@16: 
Chris@16:   Author: Frank Mori Hess <fmhess@users.sourceforge.net>
Chris@16:   Begin: 2009-05-27
Chris@16: */
Chris@16: // Copyright Frank Mori Hess 2009
Chris@16: // Use, modification and
Chris@16: // distribution is subject to the Boost Software License, Version
Chris@16: // 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: // For more information, see http://www.boost.org
Chris@16: 
Chris@16: #ifndef BOOST_SIGNALS2_DETAIL_VARIADIC_SLOT_INVOKER_HPP
Chris@16: #define BOOST_SIGNALS2_DETAIL_VARIADIC_SLOT_INVOKER_HPP
Chris@16: 
Chris@16: #include <boost/mpl/size_t.hpp>
Chris@16: #include <boost/signals2/detail/variadic_arg_type.hpp>
Chris@16: 
Chris@16: // if compiler has std::tuple use it instead of boost::tuple
Chris@16: // because boost::tuple does not have variadic template support at present.
Chris@16: #ifdef BOOST_NO_CXX11_HDR_TUPLE
Chris@16: #include <boost/tuple/tuple.hpp>
Chris@16: #define BOOST_SIGNALS2_TUPLE boost::tuple
Chris@16: #define BOOST_SIGNALS2_GET boost::get
Chris@16: #else
Chris@16: #include <tuple>
Chris@16: #define BOOST_SIGNALS2_TUPLE std::tuple
Chris@16: #define BOOST_SIGNALS2_GET std::get
Chris@16: #endif
Chris@16: 
Chris@16: namespace boost
Chris@16: {
Chris@16:   namespace signals2
Chris@16:   {
Chris@16:     namespace detail
Chris@16:     {
Chris@16:       template<unsigned ... values> class unsigned_meta_array {};
Chris@16: 
Chris@16:       template<typename UnsignedMetaArray, unsigned n> class unsigned_meta_array_appender;
Chris@16: 
Chris@16:       template<unsigned n, unsigned ... Args>
Chris@16:         class unsigned_meta_array_appender<unsigned_meta_array<Args...>, n>
Chris@16:       {
Chris@16:       public:
Chris@16:         typedef unsigned_meta_array<Args..., n> type;
Chris@16:       };
Chris@16: 
Chris@16:       template<unsigned n> class make_unsigned_meta_array;
Chris@16: 
Chris@16:       template<> class make_unsigned_meta_array<0>
Chris@16:       {
Chris@16:       public:
Chris@16:         typedef unsigned_meta_array<> type;
Chris@16:       };
Chris@16: 
Chris@16:       template<> class make_unsigned_meta_array<1>
Chris@16:       {
Chris@16:       public:
Chris@16:         typedef unsigned_meta_array<0> type;
Chris@16:       };
Chris@16: 
Chris@16:       template<unsigned n> class make_unsigned_meta_array
Chris@16:       {
Chris@16:       public:
Chris@16:         typedef typename unsigned_meta_array_appender<typename make_unsigned_meta_array<n-1>::type, n - 1>::type type;
Chris@16:       };
Chris@16: 
Chris@16:       template<typename R>
Chris@16:         class call_with_tuple_args
Chris@16:       {
Chris@16:       public:
Chris@16:         typedef R result_type;
Chris@16: 
Chris@16:         template<typename Func, typename ... Args, std::size_t N>
Chris@16:         R operator()(Func &func, BOOST_SIGNALS2_TUPLE<Args...> args, mpl::size_t<N>) const
Chris@16:         {
Chris@16:           typedef typename make_unsigned_meta_array<N>::type indices_type;
Chris@16:           typename Func::result_type *resolver = 0;
Chris@16:           return m_invoke(resolver, func, indices_type(), args);
Chris@16:         }
Chris@16:       private:
Chris@16:         template<typename T, typename Func, unsigned ... indices, typename ... Args>
Chris@16:           R m_invoke(T *, Func &func, unsigned_meta_array<indices...>, BOOST_SIGNALS2_TUPLE<Args...> args) const
Chris@16:         {
Chris@16:           return func(BOOST_SIGNALS2_GET<indices>(args)...);
Chris@16:         }
Chris@16:         template<typename Func, unsigned ... indices, typename ... Args>
Chris@16:           R m_invoke(void *, Func &func, unsigned_meta_array<indices...>, BOOST_SIGNALS2_TUPLE<Args...> args) const
Chris@16:         {
Chris@16:           func(BOOST_SIGNALS2_GET<indices>(args)...);
Chris@16:           return R();
Chris@16:         }
Chris@101:         // This overload is redundant, as it is the same as the previous variadic method when
Chris@101:         // it has zero "indices" or "Args" variadic template parameters.  This overload
Chris@101:         // only exists to quiet some unused parameter warnings
Chris@101:         // on certain compilers (some versions of gcc and msvc)
Chris@101:         template<typename Func>
Chris@101:         R m_invoke(void *, Func &func, unsigned_meta_array<>, BOOST_SIGNALS2_TUPLE<>) const
Chris@101:         {
Chris@101:           func();
Chris@101:           return R();
Chris@101:         }
Chris@16:       };
Chris@16: 
Chris@16:       template<typename R, typename ... Args>
Chris@16:         class variadic_slot_invoker
Chris@16:       {
Chris@16:       public:
Chris@16:         typedef R result_type;
Chris@16: 
Chris@16:         variadic_slot_invoker(Args & ... args): _args(args...)
Chris@16:         {}
Chris@16:         template<typename ConnectionBodyType>
Chris@16:           result_type operator ()(const ConnectionBodyType &connectionBody) const
Chris@16:         {
Chris@16:           result_type *resolver = 0;
Chris@16:           return m_invoke(connectionBody,
Chris@16:             resolver);
Chris@16:         }
Chris@16:       private:
Chris@16:         template<typename ConnectionBodyType>
Chris@16:         result_type m_invoke(const ConnectionBodyType &connectionBody,
Chris@16:           const void_type *) const
Chris@16:         {
Chris@16:           return call_with_tuple_args<result_type>()(connectionBody->slot.slot_function(), _args, mpl::size_t<sizeof...(Args)>());
Chris@16:         }
Chris@16:         template<typename ConnectionBodyType>
Chris@16:           result_type m_invoke(const ConnectionBodyType &connectionBody, ...) const
Chris@16:         {
Chris@16:           return call_with_tuple_args<result_type>()(connectionBody->slot.slot_function(), _args, mpl::size_t<sizeof...(Args)>());
Chris@16:         }
Chris@16:         BOOST_SIGNALS2_TUPLE<Args& ...> _args;
Chris@16:       };
Chris@16:     } // namespace detail
Chris@16:   } // namespace signals2
Chris@16: } // namespace boost
Chris@16: 
Chris@16: #endif // BOOST_SIGNALS2_DETAIL_VARIADIC_SLOT_INVOKER_HPP