#include <climits>

 #include <climits>

 #include <hugo/invalid.h>

 #include <hugo/invalid.h>

 #include <hugo/map_registry.h>

 #include <hugo/map_registry.h>

 #include <hugo/sym_map_factory.h>

 #include <hugo/sym_map_factory.h>

 #include <hugo/map_defines.h>

 #include <hugo/map_defines.h>

     class EdgeIt;

     class EdgeIt;

     class OutEdgeIt;

     class OutEdgeIt;

     class InEdgeIt;

     class InEdgeIt;

     CREATE_MAP_REGISTRIES;

     CREATE_MAP_REGISTRIES;

   public:

   public:

     ListGraph() 

     ListGraph() 

       : nodes(), first_node(-1),

       : nodes(), first_node(-1),

     KEEP_NODE_MAP(ListGraph);

     KEEP_NODE_MAP(ListGraph);

     KEEP_EDGE_MAP(ListGraph);

     KEEP_EDGE_MAP(ListGraph);

     CREATE_SYM_EDGE_MAP_REGISTRY;

     CREATE_SYM_EDGE_MAP_REGISTRY;

     IMPORT_SYM_EDGE_MAP(SymEdgeMapFactory);

     IMPORT_SYM_EDGE_MAP(SymEdgeMapFactory);

     SymListGraph() : ListGraph() { }

     SymListGraph() : ListGraph() { }

     SymListGraph(const ListGraph &_g) : ListGraph(_g) { }

     SymListGraph(const ListGraph &_g) : ListGraph(_g) { }

     ///Adds a pair of oppositely directed edges to the graph.

     ///Adds a pair of oppositely directed edges to the graph.

     class EdgeIt;

     class EdgeIt;

     class OutEdgeIt;

     class OutEdgeIt;

     class InEdgeIt;

     class InEdgeIt;

     CREATE_MAP_REGISTRIES;

     CREATE_MAP_REGISTRIES;

   public:

   public:

     ///Default constructor

     ///Default constructor

     NodeSet() 

     NodeSet() 

     class OutEdgeIt;

     class OutEdgeIt;

     class InEdgeIt;

     class InEdgeIt;

     CREATE_EDGE_MAP_REGISTRY;

     CREATE_EDGE_MAP_REGISTRY;

     IMPORT_EDGE_MAP(EdgeMapFactory);

     IMPORT_EDGE_MAP(EdgeMapFactory);

   public:

   public: