package body Directed_Graphs is


    pragma Warnings (Off, "variable ""Busy*"" is not referenced");
    pragma Warnings (Off, "variable ""Lock*"" is not referenced");
    --  See comment in Ada.Containers.Helpers




    ---------
    -- "=" --
    ---------

    overriding function "="
           (Left, Right : in Graph)
        return Boolean is
    begin
        return False;
    end "=";




    ------------
    -- Adjust --
    ------------

    procedure Adjust
           (Container : in out Graph) is
    begin
        null;
    end Adjust;




    ------------
    -- Append --
    ------------

    procedure Append
           (Container : in out Graph;
            Position  :    out Cursor) is
    begin
        null;
    end Append;

    procedure Append
           (Container : in out Graph;
            Label     : in     Node_Label_Type;
            Position  :    out Cursor) is
    begin
        null;
    end Append;




    ------------------
    -- Append_Label --
    ------------------

    procedure Append_Label
           (Container : in out Graph;
            Node      : in     Node_Type;
            Label     : in     Node_Label_Type) is
    begin
        null;
    end Append_Label;

    procedure Append_Label
           (Position : in out Cursor;
            Label    : in     Node_Label_Type) is
    begin
        null;
    end Append_Label;

    procedure Append_Label
           (Container : in out Graph;
            Edge      : in     Edge_Type;
            Label     : in     Edge_Label_Type) is
    begin
        null;
    end Append_Label;




    ------------
    -- Assign --
    ------------

    procedure Assign
           (Target : in out Graph;
            Source : in     Graph) is
    begin
        null;
    end Assign;




    --------------
    -- Children --
    --------------

    function Children
           (Container : in Graph;
            Node      : in Node_Type)
        return Node_Array is
    begin
        return N : Node_Array (1 .. 0);
    end Children;

    function Children
           (Position : in Cursor)
        return Node_Array is
    begin
        return N : Node_Array (1 .. 0);
    end Children;




    -----------
    -- Clear --
    -----------

    procedure Clear
           (Container : in out Graph) is
    begin
        null;
    end Clear;




    ------------------
    -- Clear_Labels --
    ------------------

    procedure Clear_Labels
           (Container : in out Graph) is
    begin
        null;
    end Clear_Labels;




    ------------------------------
    -- Constant_Label_Reference --
    ------------------------------

    function Constant_Label_Reference
           (Container : in Graph;
            Node      : in Node_Type)
        return Node_Label_Constant_Reference is
    begin
        return R : Node_Label_Constant_Reference :=
           (Element => null,
            Control => (Ada.Finalization.Controlled with null));
    end Constant_Label_Reference;

    function Constant_Label_Reference
           (Position : in Cursor)
        return Node_Label_Constant_Reference is
    begin
        return R : Node_Label_Constant_Reference :=
           (Element => null,
            Control => (Ada.Finalization.Controlled with null));
    end Constant_Label_Reference;

    function Constant_Label_Reference
           (Container : in Graph;
            Edge      : in Edge_Type)
        return Edge_Label_Constant_Reference is
    begin
        return R : Edge_Label_Constant_Reference :=
           (Element => null,
            Control => (Ada.Finalization.Controlled with null));
    end Constant_Label_Reference;




    --------------
    -- Contains --
    --------------

    function Contains
           (Container : in Graph;
            Node      : in Node_Type)
        return Boolean is
    begin
        return False;
    end Contains;

    function Contains
           (Container : in Graph;
            Node      : in Node_Type;
            Label     : in Node_Label_Type)
        return Boolean is
    begin
        return False;
    end Contains;

    function Contains
           (Container : in Graph;
            Edge      : in Edge_Type)
        return Boolean is
    begin
        return False;
    end Contains;

    function Contains
           (Container : in Graph;
            Edge      : in Edge_Type;
            Label     : in Edge_Label_Type)
        return Boolean is
    begin
        return False;
    end Contains;




    --------------------------
    -- Contains_In_Subgraph --
    --------------------------

    function Contains_In_Subgraph
           (Position : in Cursor;
            Node     : in Node_Type)
        return Boolean is
    begin
        return False;
    end Contains_In_Subgraph;

    function Contains_In_Subgraph
           (Position : in Cursor;
            Node     : in Node_Type;
            Label    : in Node_Label_Type)
        return Boolean is
    begin
        return False;
    end Contains_In_Subgraph;

    function Contains_In_Subgraph
           (Position : in Cursor;
            Edge     : in Edge_Type)
        return Boolean is
    begin
        return False;
    end Contains_In_Subgraph;

    function Contains_In_Subgraph
           (Position : in Cursor;
            Edge     : in Edge_Type;
            Label    : in Edge_Label_Type)
        return Boolean is
    begin
        return False;
    end Contains_In_Subgraph;




    --------------------
    -- Contains_Label --
    --------------------

    function Contains_Label
           (Container : in Graph;
            Label     : in Node_Label_Type)
        return Boolean is
    begin
        return False;
    end Contains_Label;

    function Contains_Label
           (Container : in Graph;
            Label     : in Edge_Label_Type)
        return Boolean is
    begin
        return False;
    end Contains_Label;




    --------------------------------
    -- Contains_Label_In_Subgraph --
    --------------------------------

    function Contains_Label_In_Subgraph
           (Position : in Cursor;
            Label    : in Node_Label_Type)
        return Boolean is
    begin
        return False;
    end Contains_Label_In_Subgraph;

    function Contains_Label_In_Subgraph
           (Position : in Cursor;
            Label    : in Edge_Label_Type)
        return Boolean is
    begin
        return False;
    end Contains_Label_In_Subgraph;




    -------------
    -- Context --
    -------------

    procedure Context
           (Container : in     Graph;
            Node      : in     Node_Type;
            Parents   :    out Node_Array;
            Children  :    out Node_Array) is
    begin
        null;
    end Context;

    procedure Context
           (Position : in     Cursor;
            Parents  :    out Node_Array;
            Children :    out Node_Array) is
    begin
        null;
    end Context;




    ----------
    -- Copy --
    ----------

    function Copy
           (Source : in Graph)
        return Graph is
    begin
        return Empty_Graph;
    end Copy;




    ------------
    -- Degree --
    ------------

    function Degree
           (Container : in Graph;
            Node      : in Node_Type)
        return Ada.Containers.Count_Type is
    begin
        return Ada.Containers.Count_Type'First;
    end Degree;

    function Degree
           (Position : in Cursor)
        return Ada.Containers.Count_Type is
    begin
        return Ada.Containers.Count_Type'First;
    end Degree;




    ------------
    -- Delete --
    ------------

    procedure Delete
           (Container : in out Graph;
            Node      : in     Node_Type) is
    begin
        null;
    end Delete;

    procedure Delete
           (Position : in out Cursor) is
    begin
        null;
    end Delete;

    procedure Delete
           (Container : in out Graph;
            Nodes     : in     Node_Array) is
    begin
        null;
    end Delete;

    procedure Delete
           (Container : in out Graph;
            Edge      : in     Edge_Type) is
    begin
        null;
    end Delete;

    procedure Delete
           (Container : in out Graph;
            Edges     : in     Edge_Array) is
    begin
        null;
    end Delete;




    ------------------
    -- Delete_Label --
    ------------------

    procedure Delete_Label
           (Container : in out Graph;
            Node      : in     Node_Type) is
    begin
        null;
    end Delete_Label;

    procedure Delete_Label
           (Position : in out Cursor) is
    begin
        null;
    end Delete_Label;

    procedure Delete_Label
           (Container : in out Graph;
            Edge      : in     Edge_Type) is
    begin
        null;
    end Delete_Label;




    ---------------------
    -- Delete_Subgraph --
    ---------------------

    procedure Delete_Subgraph
           (Position : in out Cursor) is
    begin
        null;
    end Delete_Subgraph;




    ----------------
    -- Edge_Count --
    ----------------

    function Edge_Count
           (Container : in Graph)
        return Ada.Containers.Count_Type is
    begin
        return Ada.Containers.Count_Type'First;
    end Edge_Count;




    -----------
    -- Edges --
    -----------

    function Edges
           (Container : in Graph)
        return Edge_Array is
    begin
        return E : Edge_Array (1 .. 0);
    end Edges;




    --------------
    -- Finalize --
    --------------

    procedure Finalize
           (Container : in out Graph) is
    begin
        null;
    end Finalize;

    procedure Finalize
           (Object : in out Iterator) is
    begin
        null;
    end Finalize;

    procedure Finalize
           (Object : in out Subgraph_Iterator) is
    begin
        null;
    end Finalize;




    ----------
    -- Find --
    ----------

    function Find
           (Container : in Graph;
            Label     : in Node_Label_Type)
        return Node_Array is
    begin
        return N : Node_Array (1 .. 0);
    end Find;

    function Find
           (Container : in Graph;
            Label     : in Edge_Label_Type)
        return Edge_Array is
    begin
        return E : Edge_Array (1 .. 0);
    end Find;




    ----------------------
    -- Find_In_Subgraph --
    ----------------------

    function Find_In_Subgraph
           (Position : in Cursor;
            Label    : in Node_Label_Type)
        return Node_Array is
    begin
        return N : Node_Array (1 .. 0);
    end Find_In_Subgraph;

    function Find_In_Subgraph
           (Position : in Cursor;
            Label    : in Edge_Label_Type)
        return Edge_Array is
    begin
        return E : Edge_Array (1 .. 0);
    end Find_In_Subgraph;




    -----------
    -- First --
    -----------

    function First
           (Container : in Graph)
        return Cursor is
    begin
        return No_Element;
    end First;

    function First
           (Object : in Iterator)
        return Cursor is
    begin
        return No_Element;
    end First;

    function First
           (Object : in Subgraph_Iterator)
        return Cursor is
    begin
        return No_Element;
    end First;




    --------------
    -- Has_Edge --
    --------------

    function Has_Edge
           (Container     : in Graph;
            Parent, Child : in Node_Type)
        return Boolean is
    begin
        return False;
    end Has_Edge;

    function Has_Edge
           (Parent, Child : in Cursor)
        return Boolean is
    begin
        return False;
    end Has_Edge;




    -----------------
    -- Has_Element --
    -----------------

    function Has_Element
           (Position : in Cursor)
        return Boolean is
    begin
        return False;
    end Has_Element;




    ---------------
    -- Has_Label --
    ---------------

    function Has_Label
           (Container : in Graph;
            Node      : in Node_Type)
        return Boolean is
    begin
        return False;
    end Has_Label;

    function Has_Label
           (Position : in Cursor)
        return Boolean is
    begin
        return False;
    end Has_Label;

    function Has_Label
           (Container : in Graph;
            Edge      : in Edge_Type)
        return Boolean is
    begin
        return False;
    end Has_Label;




    ----------------------
    -- Has_Labeled_Edge --
    ----------------------

    function Has_Labeled_Edge
           (Container     : in Graph;
            Parent, Child : Node_Type)
        return Boolean is
    begin
        return False;
    end Has_Labeled_Edge;

    function Has_Labeled_Edge
           (Parent, Child : in Cursor)
        return Boolean is
    begin
        return False;
    end Has_Labeled_Edge;




    ------------------
    -- Has_Neighbor --
    ------------------

    function Has_Neighbor
           (Container   : in Graph;
            Left, Right : in Node_Type)
        return Boolean is
    begin
        return False;
    end Has_Neighbor;

    function Has_Neighbor
           (Left, Right : in Cursor)
        return Boolean is
    begin
        return False;
    end Has_Neighbor;




    -------------
    -- Inbound --
    -------------

    function Inbound
           (Container : in Graph;
            Node      : in Node_Type)
        return Edge_Array is
    begin
        return E : Edge_Array (1 .. 0);
    end Inbound;

    function Inbound
           (Position : in Cursor)
        return Edge_Array is
    begin
        return E : Edge_Array (1 .. 0);
    end Inbound;




    --------------
    -- Indegree --
    --------------

    function Indegree
           (Container : in Graph;
            Node      : in Node_Type)
        return Ada.Containers.Count_Type is
    begin
        return Ada.Containers.Count_Type'First;
    end Indegree;

    function Indegree
           (Position : in Cursor)
        return Ada.Containers.Count_Type is
    begin
        return Ada.Containers.Count_Type'First;
    end Indegree;




    ------------
    -- Insert --
    ------------

    procedure Insert
           (Container : in out Graph;
            Node      : in     Node_Type) is
    begin
        null;
    end Insert;

    procedure Insert
           (Container : in out Graph;
            Node      : in     Node_Type;
            Label     : in     Node_Label_Type) is
    begin
        null;
    end Insert;

    procedure Insert
           (Container : in out Graph;
            Nodes     : in     Node_Array) is
    begin
        null;
    end Insert;

    procedure Insert
           (Container : in out Graph;
            Edge      : in     Edge_Type) is
    begin
        null;
    end Insert;

    procedure Insert
           (Container : in out Graph;
            Edge      : in     Edge_Type;
            Label     : in     Edge_Label_Type) is
    begin
        null;
    end Insert;

    procedure Insert
           (Container : in out Graph;
            Edges     : in     Edge_Array) is
    begin
        null;
    end Insert;




    --------------
    -- Is_Empty --
    --------------

    function Is_Empty
           (Container : in Graph)
        return Boolean is
    begin
        return True;
    end Is_Empty;




    -------------
    -- Iterate --
    -------------

    function Iterate
           (Container : in Graph)
        return Graph_Iterator_Interfaces.Reversible_Iterator'Class is
    begin
        return It : Iterator :=
           (Ada.Finalization.Limited_Controlled with
            Container => null,
            Node => Extended_Node_Type'First);
    end Iterate;




    ----------------------
    -- Iterate_Subgraph --
    ----------------------

    function Iterate_Subgraph
           (Container : in Graph;
            Position  : in Cursor)
        return Graph_Iterator_Interfaces.Forward_Iterator'Class is
    begin
        return It : Subgraph_Iterator :=
           (Ada.Finalization.Limited_Controlled with
            Container => null,
            Root_Node => Node_Type'First,
            Visited => Node_Vectors.Empty_Vector,
            Current => Extended_Node_Type'First);
    end Iterate_Subgraph;




    -----------
    -- Label --
    -----------

    function Label
           (Container : in Graph;
            Node      : in Node_Type)
        return Node_Label_Type is
    begin
        return N : Node_Label_Type;
    end Label;

    function Label
           (Position : in Cursor)
        return Node_Label_Type is
    begin
        return N : Node_Label_Type;
    end Label;

    function Label
           (Container : in Graph;
            Edge      : in Edge_Type)
        return Edge_Label_Type is
    begin
        return E : Edge_Label_Type;
    end Label;




    ---------------------
    -- Label_Reference --
    ---------------------

    function Label_Reference
           (Container : in Graph;
            Node      : in Node_Type)
        return Node_Label_Reference is
    begin
        return R : Node_Label_Reference :=
           (Element => null,
            Control => (Ada.Finalization.Controlled with null));
    end Label_Reference;

    function Label_Reference
           (Position : in Cursor)
        return Node_Label_Reference is
    begin
        return R : Node_Label_Reference :=
           (Element => null,
            Control => (Ada.Finalization.Controlled with null));
    end Label_Reference;

    function Label_Reference
           (Container : in Graph;
            Edge      : in Edge_Type)
        return Edge_Label_Reference is
    begin
        return R : Edge_Label_Reference :=
           (Element => null,
            Control => (Ada.Finalization.Controlled with null));
    end Label_Reference;




    ---------------------
    -- Labeled_Context --
    ---------------------

    procedure Labeled_Context
           (Container : in     Graph;
            Node      : in     Node_Type;
            Parents   :    out Node_Array;
            Children  :    out Node_Array;
            Label     :    out Node_Label_Type) is
    begin
        null;
    end Labeled_Context;

    procedure Labeled_Context
           (Position : in     Cursor;
            Parents  :    out Node_Array;
            Children :    out Node_Array;
            Label    :    out Node_Label_Type) is
    begin
        null;
    end Labeled_Context;




    ----------
    -- Last --
    ----------

    function Last
           (Container : in Graph)
        return Cursor is
    begin
        return No_Element;
    end Last;

    function Last
           (Object : in Iterator)
        return Cursor is
    begin
        return No_Element;
    end Last;




    ----------
    -- Move --
    ----------

    procedure Move
           (Target, Source : in out Graph) is
    begin
        null;
    end Move;




    ---------------
    -- Neighbors --
    ---------------

    function Neighbors
           (Container : in Graph;
            Node      : in Node_Type)
        return Node_Array is
    begin
        return N : Node_Array (1 .. 0);
    end Neighbors;

    function Neighbors
           (Position : in Cursor)
        return Node_Array is
    begin
        return N : Node_Array (1 .. 0);
    end Neighbors;




    ----------
    -- Next --
    ----------

    function Next
           (Position : in Cursor)
        return Cursor is
    begin
        return No_Element;
    end Next;

    procedure Next
           (Position : in out Cursor) is
    begin
        null;
    end Next;

    function Next
           (Object   : in Iterator;
            Position : in Cursor)
        return Cursor is
    begin
        return No_Element;
    end Next;

    function Next
           (Object   : in Subgraph_Iterator;
            Position : in Cursor)
        return Cursor is
    begin
        return No_Element;
    end Next;




    ----------------
    -- Node_Count --
    ----------------

    function Node_Count
           (Container : in Graph)
        return Ada.Containers.Count_Type is
    begin
        return Ada.Containers.Count_Type'First;
    end Node_Count;




    ----------------
    -- Node_Range --
    ----------------

    procedure Node_Range
           (Container : in     Graph;
            Minimum   :    out Node_Type;
            Maximum   :    out Node_Type) is
    begin
        null;
    end Node_Range;




    -----------
    -- Nodes --
    -----------

    function Nodes
           (Container : in Graph)
        return Node_Array is
    begin
        return N : Node_Array (1 .. 0);
    end Nodes;




    --------------
    -- Outbound --
    --------------

    function Outbound
           (Container : in Graph;
            Node      : in Node_Type)
        return Edge_Array is
    begin
        return E : Edge_Array (1 .. 0);
    end Outbound;

    function Outbound
           (Position : in Cursor)
        return Edge_Array is
    begin
        return E : Edge_Array (1 .. 0);
    end Outbound;




    ---------------
    -- Outdegree --
    ---------------

    function Outdegree
           (Container : in Graph;
            Node      : in Node_Type)
        return Ada.Containers.Count_Type is
    begin
        return Ada.Containers.Count_Type'First;
    end Outdegree;

    function Outdegree
           (Position : in Cursor)
        return Ada.Containers.Count_Type is
    begin
        return Ada.Containers.Count_Type'First;
    end Outdegree;




    -------------
    -- Parents --
    -------------

    function Parents
           (Container : in Graph;
            Node      : in Node_Type)
        return Node_Array is
    begin
        return N : Node_Array (1 .. 0);
    end Parents;

    function Parents
           (Position : in Cursor)
        return Node_Array is
    begin
        return N : Node_Array (1 .. 0);
    end Parents;




    --------------
    -- Previous --
    --------------

    function Previous
           (Position : in Cursor)
        return Cursor is
    begin
        return No_Element;
    end Previous;

    procedure Previous
           (Position : in out Cursor) is
    begin
        null;
    end Previous;

    function Previous
           (Object   : in Iterator;
            Position : in Cursor)
        return Cursor is
    begin
        return No_Element;
    end Previous;




    ----------
    -- Read --
    ----------

    procedure Read
           (Stream    : not null access Streams.Root_Stream_Type'Class;
            Container :    out          Graph) is
    begin
        null;
    end Read;

    procedure Read
           (Stream   : not null access Streams.Root_Stream_Type'Class;
            Position :    out          Cursor) is
    begin
        null;
    end Read;

    procedure Read
           (Stream : not null access Streams.Root_Stream_Type'Class;
            Item   :    out          Node_Label_Constant_Reference) is
    begin
        null;
    end Read;

    procedure Read
           (Stream : not null access Streams.Root_Stream_Type'Class;
            Item   :    out          Node_Label_Reference) is
    begin
        null;
    end Read;

    procedure Read
           (Stream : not null access Streams.Root_Stream_Type'Class;
            Item   :    out          Edge_Label_Constant_Reference) is
    begin
        null;
    end Read;

    procedure Read
           (Stream : not null access Streams.Root_Stream_Type'Class;
            Item   :    out          Edge_Label_Reference) is
    begin
        null;
    end Read;




    -------------------
    -- Replace_Label --
    -------------------

    procedure Replace_Label
           (Container : in out Graph;
            Node      : in     Node_Type;
            Label     : in     Node_Label_Type) is
    begin
        null;
    end Replace_Label;

    procedure Replace_Label
           (Position : in out Cursor;
            Label    : in     Node_Label_Type) is
    begin
        null;
    end Replace_Label;

    procedure Replace_Label
           (Container : in out Graph;
            Edge      : in     Edge_Type;
            Label     : in     Edge_Label_Type) is
    begin
        null;
    end Replace_Label;




    ----------
    -- Swap --
    ----------

    procedure Swap
           (Container   : in out Graph;
            Left, Right : in     Node_Type) is
    begin
        null;
    end Swap;

    procedure Swap
           (Left, Right : in out Cursor) is
    begin
        null;
    end Swap;




    ---------------
    -- To_Cursor --
    ---------------

    function To_Cursor
           (Container : in Graph;
            Node      : in Node_Type)
        return Cursor is
    begin
        return No_Element;
    end To_Cursor;




    --------------
    -- To_Graph --
    --------------

    function To_Graph
           (Nodes : in Node_Array;
            Edges : in Edge_Array)
        return Graph is
    begin
        return Empty_Graph;
    end To_Graph;




    -------------
    -- To_Hash --
    -------------

    function To_Hash
           (Node : in Node_Type)
        return Ada.Containers.Hash_Type is
    begin
        return Ada.Containers.Hash_Type'First;
    end To_Hash;

    function To_Hash
           (Edge : in Edge_Type)
        return Ada.Containers.Hash_Type is
    begin
        return Ada.Containers.Hash_Type'First;
    end To_Hash;




    ------------------
    -- Unused_Nodes --
    ------------------

    function Unused_Nodes
           (Container : in Graph;
            Count     : in Positive := 1)
        return Node_Array is
    begin
        return N : Node_Array (1 .. 0);
    end Unused_Nodes;




    -----------
    -- Write --
    -----------

    procedure Write
           (Stream    : not null access Streams.Root_Stream_Type'Class;
            Container : in              Graph) is
    begin
        null;
    end Write;

    procedure Write
           (Stream   : not null access Streams.Root_Stream_Type'Class;
            Position : in              Cursor) is
    begin
        null;
    end Write;

    procedure Write
           (Stream : not null access Streams.Root_Stream_Type'Class;
            Item   : in              Node_Label_Constant_Reference) is
    begin
        null;
    end Write;

    procedure Write
           (Stream : not null access Streams.Root_Stream_Type'Class;
            Item   : in              Node_Label_Reference) is
    begin
        null;
    end Write;

    procedure Write
           (Stream : not null access Streams.Root_Stream_Type'Class;
            Item   : in              Edge_Label_Constant_Reference) is
    begin
        null;
    end Write;

    procedure Write
           (Stream : not null access Streams.Root_Stream_Type'Class;
            Item   : in              Edge_Label_Reference) is
    begin
        null;
    end Write;


end Directed_Graphs;