Line data    Source code

       1             : /*
       2             :   Helper class used by variadic implementation of variadic boost::signals2::signal.
       3             : 
       4             :   Author: Frank Mori Hess <fmhess@users.sourceforge.net>
       5             :   Begin: 2009-05-27
       6             : */
       7             : // Copyright Frank Mori Hess 2009
       8             : // Use, modification and
       9             : // distribution is subject to the Boost Software License, Version
      10             : // 1.0. (See accompanying file LICENSE_1_0.txt or copy at
      11             : // http://www.boost.org/LICENSE_1_0.txt)
      12             : 
      13             : // For more information, see http://www.boost.org
      14             : 
      15             : #ifndef BOOST_SIGNALS2_DETAIL_VARIADIC_SLOT_INVOKER_HPP
      16             : #define BOOST_SIGNALS2_DETAIL_VARIADIC_SLOT_INVOKER_HPP
      17             : 
      18             : #include <boost/mpl/size_t.hpp>
      19             : #include <boost/signals2/detail/variadic_arg_type.hpp>
      20             : 
      21             : // if compiler has std::tuple use it instead of boost::tuple
      22             : // because boost::tuple does not have variadic template support at present.
      23             : #ifdef BOOST_NO_CXX11_HDR_TUPLE
      24             : #include <boost/tuple/tuple.hpp>
      25             : #define BOOST_SIGNALS2_TUPLE boost::tuple
      26             : #define BOOST_SIGNALS2_GET boost::get
      27             : #else
      28             : #include <tuple>
      29             : #define BOOST_SIGNALS2_TUPLE std::tuple
      30             : #define BOOST_SIGNALS2_GET std::get
      31             : #endif
      32             : 
      33             : // vc12 seems to erroneously report formal parameters as unreferenced (warning C4100)
      34             : // if parameters of variadic template functions are only referenced by calling
      35             : // other varadic template functions. silence these warnings:
      36             : #if defined(BOOST_MSVC)
      37             : #pragma warning(push)
      38             : #if  BOOST_MSVC >= 1800
      39             : #pragma warning(disable:4100)
      40             : #endif
      41             : #endif
      42             : 
      43             : namespace boost
      44             : {
      45             :   namespace signals2
      46             :   {
      47             :     namespace detail
      48             :     {
      49             :       template<unsigned ... values> class unsigned_meta_array {};
      50             : 
      51             :       template<typename UnsignedMetaArray, unsigned n> class unsigned_meta_array_appender;
      52             : 
      53             :       template<unsigned n, unsigned ... Args>
      54             :         class unsigned_meta_array_appender<unsigned_meta_array<Args...>, n>
      55             :       {
      56             :       public:
      57             :         typedef unsigned_meta_array<Args..., n> type;
      58             :       };
      59             : 
      60             :       template<unsigned n> class make_unsigned_meta_array;
      61             : 
      62             :       template<> class make_unsigned_meta_array<0>
      63             :       {
      64             :       public:
      65             :         typedef unsigned_meta_array<> type;
      66             :       };
      67             : 
      68             :       template<> class make_unsigned_meta_array<1>
      69             :       {
      70             :       public:
      71             :         typedef unsigned_meta_array<0> type;
      72             :       };
      73             : 
      74             :       template<unsigned n> class make_unsigned_meta_array
      75             :       {
      76             :       public:
      77             :         typedef typename unsigned_meta_array_appender<typename make_unsigned_meta_array<n-1>::type, n - 1>::type type;
      78             :       };
      79             : 
      80             :       template<typename R>
      81             :         class call_with_tuple_args
      82             :       {
      83             :       public:
      84             :         typedef R result_type;
      85             : 
      86             :         template<typename Func, typename ... Args, std::size_t N>
      87         235 :         R operator()(Func &func, const BOOST_SIGNALS2_TUPLE<Args...> & args, mpl::size_t<N>) const
      88             :         {
      89             :           typedef typename make_unsigned_meta_array<N>::type indices_type;
      90         235 :           return m_invoke<Func>(func, indices_type(), args);
      91             :         }
      92             :       private:
      93             :         template<typename Func, unsigned ... indices, typename ... Args>
      94           4 :           R m_invoke(Func &func, unsigned_meta_array<indices...>, const BOOST_SIGNALS2_TUPLE<Args...> & args,
      95             :             typename boost::disable_if<boost::is_void<typename Func::result_type> >::type * = 0
      96             :           ) const
      97             :         {
      98           4 :           return func(BOOST_SIGNALS2_GET<indices>(args)...);
      99             :         }
     100             :         template<typename Func, unsigned ... indices, typename ... Args>
     101           7 :           R m_invoke(Func &func, unsigned_meta_array<indices...>, const BOOST_SIGNALS2_TUPLE<Args...> & args,
     102             :             typename boost::enable_if<boost::is_void<typename Func::result_type> >::type * = 0
     103             :           ) const
     104             :         {
     105           7 :           func(BOOST_SIGNALS2_GET<indices>(args)...);
     106           7 :           return R();
     107             :         }
     108             :         // This overload is redundant, as it is the same as the previous variadic method when
     109             :         // it has zero "indices" or "Args" variadic template parameters.  This overload
     110             :         // only exists to quiet some unused parameter warnings
     111             :         // on certain compilers (some versions of gcc and msvc)
     112             :         template<typename Func>
     113         224 :           R m_invoke(Func &func, unsigned_meta_array<>, const BOOST_SIGNALS2_TUPLE<> &, 
     114             :             typename boost::enable_if<boost::is_void<typename Func::result_type> >::type * = 0
     115             :           ) const
     116             :         {
     117         224 :           func();
     118         224 :           return R();
     119             :         }
     120             :       };
     121             : 
     122             :       template<typename R, typename ... Args>
     123             :         class variadic_slot_invoker
     124             :       {
     125             :       public:
     126             :         typedef R result_type;
     127             : 
     128      164664 :         variadic_slot_invoker(Args & ... args): _args(args...)
     129      164664 :         {}
     130             :         template<typename ConnectionBodyType>
     131         235 :           result_type operator ()(const ConnectionBodyType &connectionBody) const
     132             :         {
     133         246 :           return call_with_tuple_args<result_type>()(connectionBody->slot().slot_function(), 
     134          11 :             _args, mpl::size_t<sizeof...(Args)>());
     135             :         }
     136             :       private:
     137             :         BOOST_SIGNALS2_TUPLE<Args& ...> _args;
     138             :       };
     139             :     } // namespace detail
     140             :   } // namespace signals2
     141             : } // namespace boost
     142             : 
     143             : #if defined(BOOST_MSVC)
     144             : #pragma warning(pop)
     145             : #endif
     146             : 
     147             : 
     148             : #endif // BOOST_SIGNALS2_DETAIL_VARIADIC_SLOT_INVOKER_HPP