ceph/src/boost/libs/msm/include/boost/msm/front/detail/common_states.hpp

   1 // Copyright 2008 Christophe Henry
   2 // henry UNDERSCORE christophe AT hotmail DOT com
   3 // This is an extended version of the state machine available in the boost::mpl library
   4 // Distributed under the same license as the original.
   5 // Copyright for the original version:
   6 // Copyright 2005 David Abrahams and Aleksey Gurtovoy. Distributed
   7 // under the Boost Software License, Version 1.0. (See accompanying
   8 // file LICENSE_1_0.txt or copy at
   9 // http://www.boost.org/LICENSE_1_0.txt)
  10
  11 #ifndef BOOST_MSM_FRONT_DETAILS_COMMON_STATES_H
  12 #define BOOST_MSM_FRONT_DETAILS_COMMON_STATES_H
  13
  14 #include <boost/mpl/int.hpp>
  15
  16 #include <boost/mpl/vector.hpp>
  17 #include <boost/fusion/container/map.hpp>
  18 #include <boost/fusion/include/at_key.hpp>
  19 #include <boost/type_traits/add_const.hpp>
  20
  21 namespace boost { namespace msm { namespace front {namespace detail
  22 {
  23 template <class Attributes= ::boost::fusion::map<> >
  24 struct inherit_attributes
  25 {
  26     inherit_attributes():m_attributes(){}
  27     inherit_attributes(Attributes const& the_attributes):m_attributes(the_attributes){}
  28     // on the fly attribute creation capability
  29     typedef Attributes      attributes_type;
  30     template <class Index>
  31     typename ::boost::fusion::result_of::at_key<attributes_type,
  32                                                 Index>::type
  33     get_attribute(Index const&)
  34     {
  35         return ::boost::fusion::at_key<Index>(m_attributes);
  36     }
  37
  38     template <class Index>
  39     typename ::boost::add_const<
  40         typename ::boost::fusion::result_of::at_key<attributes_type,
  41                                                     Index>::type>::type
  42     get_attribute(Index const&)const
  43     {
  44         return const_cast<
  45             typename ::boost::add_const<
  46                 typename ::boost::fusion::result_of::at_key< attributes_type,
  47                                                              Index >::type>::type>
  48                                 (::boost::fusion::at_key<Index>(m_attributes));
  49     }
  50
  51 private:
  52     // attributes
  53     Attributes m_attributes;
  54 };
  55
  56 // the interface for all states. Defines entry and exit functions. Overwrite to implement for any state needing it.
  57 template<class USERBASE,class Attributes= ::boost::fusion::map<> >
  58 struct state_base : public inherit_attributes<Attributes>, USERBASE
  59 {
  60     typedef USERBASE        user_state_base;
  61     typedef Attributes      attributes_type;
  62
  63     // empty implementation for the states not wishing to define an entry condition
  64     // will not be called polymorphic way
  65     template <class Event,class FSM>
  66     void on_entry(Event const& ,FSM&){}
  67     template <class Event,class FSM>
  68     void on_exit(Event const&,FSM& ){}
  69     // default (empty) transition table;
  70     typedef ::boost::mpl::vector0<>  internal_transition_table;
  71     typedef ::boost::mpl::vector0<>  transition_table;
  72 };
  73
  74 }}}}
  75
  76 #endif //BOOST_MSM_FRONT_DETAILS_COMMON_STATES_H
  77