// Boost.Signals library // Copyright Douglas Gregor 2001-2004. // Copyright Frank Mori Hess 2007. 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_SIGNALS_COMMON_HPP #define BOOST_SIGNALS2_SIGNALS_COMMON_HPP #include <boost/mpl/bool.hpp> #include <boost/mpl/if.hpp> #include <boost/ref.hpp> #include <boost/signals2/signal_base.hpp> #include <boost/type_traits/is_base_of.hpp> namespace boost { namespace signals2 { namespace detail { // Determine if the given type T is a signal template<typename T> class is_signal: public mpl::bool_<is_base_of<signal_base, T>::value> {}; // A slot can be a signal, a reference to a function object, or a // function object. struct signal_tag {}; struct reference_tag {}; struct value_tag {}; // Classify the given slot as a signal, a reference-to-slot, or a // standard slot template<typename S> class get_slot_tag { typedef typename mpl::if_<is_signal<S>, signal_tag, value_tag>::type signal_or_value; public: typedef typename mpl::if_<is_reference_wrapper<S>, reference_tag, signal_or_value>::type type; }; // Get the slot so that it can be copied template<typename F> typename F::weak_signal_type get_invocable_slot(const F &signal, signal_tag) { return typename F::weak_signal_type(signal); } template<typename F> const F& get_invocable_slot(const F& f, reference_tag) { return f; } template<typename F> const F& get_invocable_slot(const F& f, value_tag) { return f; } // Determines the type of the slot - is it a signal, a reference to a // slot or just a normal slot. template<typename F> typename get_slot_tag<F>::type tag_type(const F&) { typedef typename get_slot_tag<F>::type the_tag_type; the_tag_type tag = the_tag_type(); return tag; } } // end namespace detail } // end namespace signals2 } // end namespace boost #endif // BOOST_SIGNALS2_SIGNALS_COMMON_HPP