boost/statechart/event_base.hpp

0001 #ifndef BOOST_STATECHART_EVENT_BASE_HPP_INCLUDED
0002 #define BOOST_STATECHART_EVENT_BASE_HPP_INCLUDED
0003 //////////////////////////////////////////////////////////////////////////////
0004 // Copyright 2002-2006 Andreas Huber Doenni
0005 // Distributed under the Boost Software License, Version 1.0. (See accompany-
0006 // ing file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
0007 //////////////////////////////////////////////////////////////////////////////
0008
0009
0010
0011 #include <boost/statechart/detail/rtti_policy.hpp>
0012 #include <boost/statechart/detail/counted_base.hpp>
0013
0014 #include <boost/assert.hpp>
0015 #include <boost/intrusive_ptr.hpp>
0016 #include <boost/config.hpp>
0017
0018
0019
0020 namespace boost
0021 {
0022 namespace statechart
0023 {
0024 namespace detail
0025 {
0026
0027
0028
0029 // This helper is necessary because there doesn't seem to be consensus among
0030 // compilers on how a friend declaration for a function in another namespace
0031 // has to look like.
0032 class delete_helper
0033 {
0034   public:
0035     template< class T >
0036     static void delete_object( const T * pObject )
0037     {
0038       delete pObject;
0039     }
0040 };
0041
0042
0043
0044 } // namespace detail
0045
0046
0047
0048 //////////////////////////////////////////////////////////////////////////////
0049 class event_base : public detail::rtti_policy::rtti_base_type<
0050   detail::counted_base<> >
0051 {
0052   typedef detail::rtti_policy::rtti_base_type<
0053     detail::counted_base<> > base_type;
0054   public:
0055     //////////////////////////////////////////////////////////////////////////
0056     intrusive_ptr< const event_base > intrusive_from_this() const;
0057
0058   protected:
0059     //////////////////////////////////////////////////////////////////////////
0060     event_base( detail::rtti_policy::id_provider_type idProvider ) :
0061       base_type( idProvider )
0062     {
0063     }
0064
0065     virtual ~event_base() {}
0066
0067   private:
0068     //////////////////////////////////////////////////////////////////////////
0069     virtual intrusive_ptr< const event_base > clone() const = 0;
0070
0071     friend class detail::delete_helper;
0072 };
0073
0074
0075
0076 #ifdef BOOST_NO_ARGUMENT_DEPENDENT_LOOKUP
0077 } // namespace statechart
0078 #endif
0079
0080
0081
0082 inline void intrusive_ptr_add_ref( const ::boost::statechart::event_base * pBase )
0083 {
0084   pBase->add_ref();
0085 }
0086
0087 inline void intrusive_ptr_release( const ::boost::statechart::event_base * pBase )
0088 {
0089   if ( pBase->release() )
0090   {
0091     ::boost::statechart::detail::delete_helper::delete_object( pBase );
0092   }
0093 }
0094
0095
0096
0097 #ifndef BOOST_NO_ARGUMENT_DEPENDENT_LOOKUP
0098 } // namespace statechart
0099 #endif
0100 namespace statechart
0101 {
0102
0103
0104
0105 // We're implementing this here so that GCC3.4.2 can find
0106 // intrusive_ptr_add_ref, which is indirectly called from the intrusive_ptr
0107 // ctor.
0108 inline intrusive_ptr< const event_base > event_base::intrusive_from_this() const
0109 {
0110   if ( base_type::ref_counted() )
0111   {
0112     return intrusive_ptr< const event_base >( this );
0113   }
0114   else
0115   {
0116     return clone();
0117   }
0118 }
0119
0120
0121
0122 } // namespace statechart
0123 } // namespace boost
0124
0125
0126
0127 #endif