使用戦略パターン

Question

でカスタムプロパティとBGLのdijsktraコードは、私のコードは次のようになります。

---------------| 
| worker  |  ____________________ 
| --------- |<-----|     |     
| | graph | |  |strategy interface|<----- concrete strategy 
| |--------| |  -------------------- 
|--------------| 

グラフクラスタイプ」のように、いくつかのブースト・グラフのコードで、作業員の内部にネストされたクラスでありますdefine '、および' add_edge 'です。 戦略インタフェースには、 'int DoRoute（int src、int dst）'というインタフェースが1つしかありません。

問題はです。私はどのように 'DoRoute'のdijsktraのようなブーストグラフアルゴリズムを使用できますか？

例のコードは次のようになります。

enum edge_mycost_t {edge_mycost}; 
namespace boost { 
    BOOST_INSTALL_PROPERTY(edge, mycost); 
} 
class woker { 
    public : 
    class graph { 
     public : 
     using EdgeProperties = boost::property<edge_mycost_t, int>; 
     using NameProperties = boost::property<boost::vertex_name_t, std::string>; 
     using Graph = boost::adjacency_list < boost::vecS, boost::vecS, boost::directedS, NameProperties, EdgeProperties, boost::no_property>; 
     graph() { 
      //... add_edge etc... 
     } 
    } 
    work() { 
     // create g_ etc... 
    } 
    graph g_; 
    strategy_interface* p_si_; 
    friend strategy_interface; 
} 

class strategy_interface { 
    public : 
    stategy_interface(worker& w) : work_(w) {} 
    int DoRoute(int, int) = 0; 
    protected : 
    worker::graph get_graph() { 
     return work_.g_; 
    } 
    private : 
    worker& work_; 
} 

class concrete_strategy : public strategy_interface { 
    public : 
    concrete_strategy(worker& w) : strategy_interface(w) {} 
    int DoRoute(int s, int d) override { 
     auto g = strategy_interface::get_graph(); 
     using Graph_T = decltype(g); 
     std::vector<Vertex_D> pm(num_vertices(g)); 
     std::vector<int> dm(num_vertices(g)); 
     auto s_des = pm[s]; 
     boost::dijkstra_shortest_paths(g, s_des, 
       predecessor_map(boost::make_iterator_property_map(pm.begin(), get(boost::vertex_index, 
       distance_map(boost::make_iterator_property_map(dm.begin(), get(boost::vertex_index, g))) 
     );  
     // can't compile 
    } 
} 

エラー：

In file included from /usr/include/boost/graph/adjacency_list.hpp:246:0, 
       from ./ns3/common_header.h:27, 
       from ./ns3/dtn_package.h:14, 
       from ./ns3/ns3dtn-bit.h:20, 
       from ./ns3/ns3dtn-bit-helper.h:6, 
       from ../src/ns3dtn-bit/examples/ns3dtn-bit-your-example.cpp:7: 
/usr/include/boost/graph/detail/adjacency_list.hpp: In instantiation of ‘struct boost::detail::adj_list_any_edge_pmap::bind_<boost::adjacency_list<boost::vecS, boost::vecS, boost::directedS, boost::property<boost::vertex_name_t, std::__cxx11::basic_string<char> >, boost::property<edge_mycost_t, int>, boost::no_property>, boost::property<edge_mycost_t, int>, boost::edge_weight_t>’: 
/usr/include/boost/graph/detail/adjacency_list.hpp:2728:12: required from ‘struct boost::detail::adj_list_choose_edge_pmap<boost::edge_weight_t, boost::adjacency_list<boost::vecS, boost::vecS, boost::directedS, boost::property<boost::vertex_name_t, std::__cxx11::basic_string<char> >, boost::property<edge_mycost_t, int>, boost::no_property>, boost::property<edge_mycost_t, int> >’ 
/usr/include/boost/graph/detail/adjacency_list.hpp:2733:14: required from ‘struct boost::detail::adj_list_edge_property_selector::bind_<boost::adjacency_list<boost::vecS, boost::vecS, boost::directedS, boost::property<boost::vertex_name_t, std::__cxx11::basic_string<char> >, boost::property<edge_mycost_t, int>, boost::no_property>, boost::property<edge_mycost_t, int>, boost::edge_weight_t>’ 
/usr/include/boost/graph/properties.hpp:192:12: required from ‘struct boost::detail::edge_property_map<boost::adjacency_list<boost::vecS, boost::vecS, boost::directedS, boost::property<boost::vertex_name_t, std::__cxx11::basic_string<char> >, boost::property<edge_mycost_t, int>, boost::no_property>, boost::edge_weight_t>’ 
/usr/include/boost/graph/properties.hpp:212:10: required from ‘struct boost::property_map<boost::adjacency_list<boost::vecS, boost::vecS, boost::directedS, boost::property<boost::vertex_name_t, std::__cxx11::basic_string<char> >, boost::property<edge_mycost_t, int>, boost::no_property>, boost::edge_weight_t, void>’ 
/usr/include/boost/mpl/eval_if.hpp:38:31: recursively required from ‘struct boost::mpl::eval_if<mpl_::bool_<true>, boost::detail::const_type_as_type<boost::property_map<boost::adjacency_list<boost::vecS, boost::vecS, boost::directedS, boost::property<boost::vertex_name_t, std::__cxx11::basic_string<char> >, boost::property<edge_mycost_t, int>, boost::no_property>, boost::edge_weight_t, void> >, boost::property_map<boost::adjacency_list<boost::vecS, boost::vecS, boost::directedS, boost::property<boost::vertex_name_t, std::__cxx11::basic_string<char> >, boost::property<edge_mycost_t, int>, boost::no_property>, boost::edge_weight_t, void> >’ 
/usr/include/boost/mpl/eval_if.hpp:38:31: required from ‘struct boost::mpl::eval_if<boost::is_same<boost::param_not_found, boost::param_not_found>, boost::mpl::eval_if<mpl_::bool_<true>, boost::detail::const_type_as_type<boost::property_map<boost::adjacency_list<boost::vecS, boost::vecS, boost::directedS, boost::property<boost::vertex_name_t, std::__cxx11::basic_string<char> >, boost::property<edge_mycost_t, int>, boost::no_property>, boost::edge_weight_t, void> >, boost::property_map<boost::adjacency_list<boost::vecS, boost::vecS, boost::directedS, boost::property<boost::vertex_name_t, std::__cxx11::basic_string<char> >, boost::property<edge_mycost_t, int>, boost::no_property>, boost::edge_weight_t, void> >, boost::mpl::identity<boost::param_not_found> >’ 
/usr/include/boost/graph/named_function_params.hpp:269:12: required from ‘struct boost::detail::choose_impl_result<mpl_::bool_<true>, boost::adjacency_list<boost::vecS, boost::vecS, boost::directedS, boost::property<boost::vertex_name_t, std::__cxx11::basic_string<char> >, boost::property<edge_mycost_t, int>, boost::no_property>, boost::param_not_found, boost::edge_weight_t>’ 
/usr/include/boost/graph/named_function_params.hpp:305:3: required by substitution of ‘template<class Param, class Graph, class PropertyTag> typename boost::detail::choose_impl_result<mpl_::bool_<true>, Graph, Param, PropertyTag>::type boost::choose_const_pmap(const Param&, const Graph&, PropertyTag) [with Param = boost::param_not_found; Graph = boost::adjacency_list<boost::vecS, boost::vecS, boost::directedS, boost::property<boost::vertex_name_t, std::__cxx11::basic_string<char> >, boost::property<edge_mycost_t, int>, boost::no_property>; PropertyTag = boost::edge_weight_t]’ 
/usr/include/boost/graph/dijkstra_shortest_paths.hpp:612:25: required from ‘void boost::dijkstra_shortest_paths(const VertexListGraph&, typename boost::graph_traits<Graph>::vertex_descriptor, const boost::bgl_named_params<T, Tag, Base>&) [with VertexListGraph = boost::adjacency_list<boost::vecS, boost::vecS, boost::directedS, boost::property<boost::vertex_name_t, std::__cxx11::basic_string<char> >, boost::property<edge_mycost_t, int>, boost::no_property>; Param = boost::iterator_property_map<__gnu_cxx::__normal_iterator<int*, std::vector<int> >, boost::vec_adj_list_vertex_id_map<boost::property<boost::vertex_name_t, std::__cxx11::basic_string<char> >, long unsigned int>, int, int&>; Tag = boost::vertex_distance_t; Rest = boost::bgl_named_params<boost::iterator_property_map<__gnu_cxx::__normal_iterator<long unsigned int*, std::vector<long unsigned int> >, boost::vec_adj_list_vertex_id_map<boost::property<boost::vertex_name_t, std::__cxx11::basic_string<char> >, long unsigned int>, long unsigned int, long unsigned int&>, boost::vertex_predecessor_t, boost::no_property>; typename boost::graph_traits<Graph>::vertex_descriptor = long unsigned int]’ 
../src/ns3dtn-bit/examples/ns3dtn-bit-your-example.cpp:36:29: required from here 
/usr/include/boost/graph/detail/adjacency_list.hpp:2696:29: error: forming reference to void 
     typedef value_type& reference; 
          ^
/usr/include/boost/graph/detail/adjacency_list.hpp:2697:35: error: forming reference to void 
     typedef const value_type& const_reference; 
           ^
/usr/include/boost/graph/detail/adjacency_list.hpp:2701:61: error: forming reference to void 
      typename Graph::vertex_descriptor,Property,Tag> type; 
                  ^
/usr/include/boost/graph/detail/adjacency_list.hpp:2704:68: error: forming reference to void 
      typename Graph::vertex_descriptor,const Property, Tag> const_type; 
                    ^
In file included from ./ns3/common_header.h:29:0, 
       from ./ns3/dtn_package.h:14, 
       from ./ns3/ns3dtn-bit.h:20, 
       from ./ns3/ns3dtn-bit-helper.h:6, 
       from ../src/ns3dtn-bit/examples/ns3dtn-bit-your-example.cpp:7: 
/usr/include/boost/graph/dijkstra_shortest_paths.hpp: In instantiation of ‘void boost::dijkstra_shortest_paths(const VertexListGraph&, typename boost::graph_traits<Graph>::vertex_descriptor, const boost::bgl_named_params<T, Tag, Base>&) [with VertexListGraph = boost::adjacency_list<boost::vecS, boost::vecS, boost::directedS, boost::property<boost::vertex_name_t, std::__cxx11::basic_string<char> >, boost::property<edge_mycost_t, int>, boost::no_property>; Param = boost::iterator_property_map<__gnu_cxx::__normal_iterator<int*, std::vector<int> >, boost::vec_adj_list_vertex_id_map<boost::property<boost::vertex_name_t, std::__cxx11::basic_string<char> >, long unsigned int>, int, int&>; Tag = boost::vertex_distance_t; Rest = boost::bgl_named_params<boost::iterator_property_map<__gnu_cxx::__normal_iterator<long unsigned int*, std::vector<long unsigned int> >, boost::vec_adj_list_vertex_id_map<boost::property<boost::vertex_name_t, std::__cxx11::basic_string<char> >, long unsigned int>, long unsigned int, long unsigned int&>, boost::vertex_predecessor_t, boost::no_property>; typename boost::graph_traits<Graph>::vertex_descriptor = long unsigned int]’: 
../src/ns3dtn-bit/examples/ns3dtn-bit-your-example.cpp:36:29: required from here 
/usr/include/boost/graph/dijkstra_shortest_paths.hpp:612:25: error: no matching function for call to ‘choose_const_pmap(const type&, const boost::adjacency_list<boost::vecS, boost::vecS, boost::directedS, boost::property<boost::vertex_name_t, std::__cxx11::basic_string<char> >, boost::property<edge_mycost_t, int>, boost::no_property>&, boost::edge_weight_t)’ 
     choose_const_pmap(get_param(params, edge_weight), g, edge_weight), 
         ^
In file included from /usr/include/boost/graph/dijkstra_shortest_paths.hpp:20:0, 
       from ./ns3/common_header.h:29, 
       from ./ns3/dtn_package.h:14, 
       from ./ns3/ns3dtn-bit.h:20, 
       from ./ns3/ns3dtn-bit-helper.h:6, 
       from ../src/ns3dtn-bit/examples/ns3dtn-bit-your-example.cpp:7: 
/usr/include/boost/graph/named_function_params.hpp:305:3: note: candidate: template<class Param, class Graph, class PropertyTag> typename boost::detail::choose_impl_result<mpl_::bool_<true>, Graph, Param, PropertyTag>::type boost::choose_const_pmap(const Param&, const Graph&, PropertyTag) 
    choose_const_pmap(const Param& p, const Graph& g, PropertyTag tag) 
^
/usr/include/boost/graph/named_function_params.hpp:305:3: note: substitution of deduced template arguments resulted in errors seen above 

Answer 1

代わりに '内部プロパティ' を使用しての、あなたがバンドルされたプロパティを使用する方が喜んかもしれません。ちょうどこのように：

struct your_edge_properties { 
    //... 
} 
graph { 
    using EdgeProperties = your_edge_properties; 
    //... 
} 
int DoRoute(int s, int d) { 
    //... 
    dijkstra_shortest_paths(g, s_des, 
      weight_map(get(&your_edge_properties::cost, g)). 
      distance_map(make_iterator_property_map(distances.begin(), get(vertex_index, g)))); 
    // then process for your result 
} 

チェックit私はなぜデザインパターンが重要かわかりません。助けてもいいかもしれない。