/* | |
Helper class used by variadic implementation of variadic boost::signals2::signal. | |
Author: Frank Mori Hess <fmhess@users.sourceforge.net> | |
Begin: 2009-05-27 | |
*/ | |
// Copyright Frank Mori Hess 2009 | |
// Use, modification and | |
// distribution is 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) | |
// For more information, see http://www.boost.org | |
#ifndef BOOST_SIGNALS2_DETAIL_VARIADIC_SLOT_INVOKER_HPP | |
#define BOOST_SIGNALS2_DETAIL_VARIADIC_SLOT_INVOKER_HPP | |
#include <boost/signals2/detail/variadic_arg_type.hpp> | |
// if compiler has variadic template support, we assume they have | |
// a variadic std::tuple implementation here. We don't use boost::tuple | |
// because it does not have variadic template support at present. | |
#include <tuple> | |
namespace boost | |
{ | |
namespace signals2 | |
{ | |
namespace detail | |
{ | |
template<unsigned ... values> class unsigned_meta_array {}; | |
template<typename UnsignedMetaArray, unsigned n> class unsigned_meta_array_appender; | |
template<unsigned n, unsigned ... Args> | |
class unsigned_meta_array_appender<unsigned_meta_array<Args...>, n> | |
{ | |
public: | |
typedef unsigned_meta_array<Args..., n> type; | |
}; | |
template<unsigned n> class make_unsigned_meta_array; | |
template<> class make_unsigned_meta_array<0> | |
{ | |
public: | |
typedef unsigned_meta_array<> type; | |
}; | |
template<> class make_unsigned_meta_array<1> | |
{ | |
public: | |
typedef unsigned_meta_array<0> type; | |
}; | |
template<unsigned n> class make_unsigned_meta_array | |
{ | |
public: | |
typedef typename unsigned_meta_array_appender<typename make_unsigned_meta_array<n-1>::type, n - 1>::type type; | |
}; | |
template<typename R> | |
class call_with_tuple_args | |
{ | |
public: | |
typedef R result_type; | |
template<typename Func, typename ... Args> | |
R operator()(Func &func, std::tuple<Args...> args) const | |
{ | |
typedef typename make_unsigned_meta_array<sizeof...(Args)>::type indices_type; | |
typename Func::result_type *resolver = 0; | |
return m_invoke(resolver, func, indices_type(), args); | |
} | |
private: | |
template<typename T, typename Func, unsigned ... indices, typename ... Args> | |
R m_invoke(T *, Func &func, unsigned_meta_array<indices...>, std::tuple<Args...> args) const | |
{ | |
return func(std::get<indices>(args)...); | |
} | |
template<typename Func, unsigned ... indices, typename ... Args> | |
R m_invoke(void *, Func &func, unsigned_meta_array<indices...>, std::tuple<Args...> args) const | |
{ | |
func(std::get<indices>(args)...); | |
return R(); | |
} | |
}; | |
template<typename R, typename ... Args> | |
class variadic_slot_invoker | |
{ | |
public: | |
typedef R result_type; | |
variadic_slot_invoker(Args & ... args): _args(args...) | |
{} | |
template<typename ConnectionBodyType> | |
result_type operator ()(const ConnectionBodyType &connectionBody) const | |
{ | |
result_type *resolver = 0; | |
return m_invoke(connectionBody, | |
resolver); | |
} | |
private: | |
template<typename ConnectionBodyType> | |
result_type m_invoke(const ConnectionBodyType &connectionBody, | |
const void_type *) const | |
{ | |
return call_with_tuple_args<result_type>()(connectionBody->slot.slot_function(), _args); | |
return void_type(); | |
} | |
template<typename ConnectionBodyType> | |
result_type m_invoke(const ConnectionBodyType &connectionBody, ...) const | |
{ | |
return call_with_tuple_args<result_type>()(connectionBody->slot.slot_function(), _args); | |
} | |
std::tuple<Args& ...> _args; | |
}; | |
} // namespace detail | |
} // namespace signals2 | |
} // namespace boost | |
#endif // BOOST_SIGNALS2_DETAIL_VARIADIC_SLOT_INVOKER_HPP |