Chris@16: // Boost.Signals library
Chris@16: 
Chris@16: // Copyright Douglas Gregor 2001-2004.
Chris@16: // Copyright Frank Mori Hess 2007. 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_SIGNALS_COMMON_HPP
Chris@16: #define BOOST_SIGNALS2_SIGNALS_COMMON_HPP
Chris@16: 
Chris@16: #include <boost/mpl/bool.hpp>
Chris@16: #include <boost/mpl/if.hpp>
Chris@16: #include <boost/ref.hpp>
Chris@16: #include <boost/signals2/signal_base.hpp>
Chris@16: #include <boost/type_traits/is_base_of.hpp>
Chris@16: 
Chris@16: namespace boost {
Chris@16:   namespace signals2 {
Chris@16:     namespace detail {
Chris@16:       // Determine if the given type T is a signal
Chris@16:       template<typename T>
Chris@16:       class is_signal: public mpl::bool_<is_base_of<signal_base, T>::value>
Chris@16:       {};
Chris@16: 
Chris@16:       // A slot can be a signal, a reference to a function object, or a
Chris@16:       // function object.
Chris@16:       struct signal_tag {};
Chris@16:       struct reference_tag {};
Chris@16:       struct value_tag {};
Chris@16: 
Chris@16:       // Classify the given slot as a signal, a reference-to-slot, or a
Chris@16:       // standard slot
Chris@16:       template<typename S>
Chris@16:       class get_slot_tag {
Chris@16:         typedef typename mpl::if_<is_signal<S>,
Chris@16:           signal_tag, value_tag>::type signal_or_value;
Chris@16:       public:
Chris@16:         typedef typename mpl::if_<is_reference_wrapper<S>,
Chris@16:                             reference_tag,
Chris@16:                             signal_or_value>::type type;
Chris@16:       };
Chris@16: 
Chris@16:       // Get the slot so that it can be copied
Chris@16:       template<typename F>
Chris@16:       typename F::weak_signal_type
Chris@16:       get_invocable_slot(const F &signal, signal_tag)
Chris@16:       { return typename F::weak_signal_type(signal); }
Chris@16: 
Chris@16:       template<typename F>
Chris@16:       const F&
Chris@16:       get_invocable_slot(const F& f, reference_tag)
Chris@16:       { return f; }
Chris@16: 
Chris@16:       template<typename F>
Chris@16:       const F&
Chris@16:       get_invocable_slot(const F& f, value_tag)
Chris@16:       { return f; }
Chris@16: 
Chris@16:       // Determines the type of the slot - is it a signal, a reference to a
Chris@16:       // slot or just a normal slot.
Chris@16:       template<typename F>
Chris@16:       typename get_slot_tag<F>::type
Chris@16:       tag_type(const F&)
Chris@16:       {
Chris@16:         typedef typename get_slot_tag<F>::type
Chris@16:           the_tag_type;
Chris@16:         the_tag_type tag = the_tag_type();
Chris@16:         return tag;
Chris@16:       }
Chris@16:     } // end namespace detail
Chris@16:   } // end namespace signals2
Chris@16: } // end namespace boost
Chris@16: 
Chris@16: #endif // BOOST_SIGNALS2_SIGNALS_COMMON_HPP