std::vector<NodeT> nodes;

     std::vector<NodeT> nodes;

     std::vector<ArcT> arcs;

     std::vector<ArcT> arcs;

   public:

   public:

     class Node;

     class Node;

     class Arc;

     class Arc;

   public:

   public:

   ///node and arc deletions</b>.

   ///node and arc deletions</b>.

   ///It fully conforms to the \ref concepts::Digraph "Digraph concept".

   ///It fully conforms to the \ref concepts::Digraph "Digraph concept".

   ///

   ///

   ///\sa concepts::Digraph.

   ///\sa concepts::Digraph.

   class SmartDigraph : public ExtendedSmartDigraphBase {

   class SmartDigraph : public ExtendedSmartDigraphBase {

     typedef ExtendedSmartDigraphBase Parent;

     typedef ExtendedSmartDigraphBase Parent;

   private:

   private:

     ///SmartDigraph is \e not copy constructible. Use DigraphCopy() instead.

     ///SmartDigraph is \e not copy constructible. Use DigraphCopy() instead.

     int first_free_arc;

     int first_free_arc;

   public:

   public:

     class Node;

     class Node;

     class Arc;

     class Arc;

     class Edge;

     class Edge;

   /// node and arc deletions</b>.

   /// node and arc deletions</b>.

   /// It fully conforms to the \ref concepts::Graph "Graph concept".

   /// It fully conforms to the \ref concepts::Graph "Graph concept".

   ///

   ///

   /// \sa concepts::Graph.

   /// \sa concepts::Graph.

   class SmartGraph : public ExtendedSmartGraphBase {

   class SmartGraph : public ExtendedSmartGraphBase {

   private:

   private:

     ///SmartGraph is \e not copy constructible. Use GraphCopy() instead.

     ///SmartGraph is \e not copy constructible. Use GraphCopy() instead.

     ///SmartGraph is \e not copy constructible. Use GraphCopy() instead.

     ///SmartGraph is \e not copy constructible. Use GraphCopy() instead.

     ///Assignment of SmartGraph to another one is \e not allowed.

     ///Assignment of SmartGraph to another one is \e not allowed.

     ///Use GraphCopy() instead.

     ///Use GraphCopy() instead.

     void operator=(const SmartGraph &) {}

     void operator=(const SmartGraph &) {}

   public:

   public:

     /// Constructor

     /// Constructor

     /// Constructor.

     /// Constructor.

     ///

     ///