Index: graphviz.hpp
===================================================================
RCS file: /cvsroot/boost/boost/boost/graph/graphviz.hpp,v
retrieving revision 1.14
diff -c -3 -p -r1.14 graphviz.hpp
*** graphviz.hpp	2001/11/03 19:13:47	1.14
--- graphviz.hpp	2001/12/06 20:35:04
*************** namespace boost {
*** 78,83 ****
--- 78,84 ----
    private:
      Name name;
    };
+ 
    template <class Name>
    inline label_writer<Name>
    make_label_writer(Name n) {
*************** namespace boost {
*** 111,116 ****
--- 112,138 ----
      }
    }
  
+   template<typename Attributes>
+   inline void write_all_attributes(Attributes attributes, 
+                                    const std::string& name,
+                                    std::ostream& out)
+   {
+     typename Attributes::const_iterator i = attributes.begin(),
+                                         end = attributes.end();
+     if (i != end) {
+       out << name << " [\n";
+       write_attributes(attributes, out);
+       out << "];\n";
+     }
+   }
+ 
+   inline void write_all_attributes(detail::error_property_not_found,
+                                    const std::string&,
+                                    std::ostream&)
+   {
+     // Do nothing - no attributes exist
+   }
+ 
    template <typename GraphGraphAttributes,
              typename GraphNodeAttributes,
              typename GraphEdgeAttributes>
*************** namespace boost {
*** 122,160 ****
        : g_attributes(gg), n_attributes(gn), e_attributes(ge) { }
  
      void operator()(std::ostream& out) const {
!       
!       typename GraphGraphAttributes::const_iterator
!         gi = g_attributes.begin(),
!         gend = g_attributes.end();
! 
!       if ( gi != gend ) {
!         out << "graph [";
!         write_attributes(g_attributes, out);
!         out << "];" << std::endl;
!       }
! 
!       //write node [......]; if need
!       typename GraphNodeAttributes::const_iterator
!         ni = n_attributes.begin(),
!         nend = n_attributes.end();
! 
!       if ( ni != nend ) {
!         out << "node [";
!         write_attributes(n_attributes, out);
!         out << "];" << std::endl;
!       }
! 
!       //write edge[....]; if need
!       typename GraphEdgeAttributes::const_iterator 
!         ei = e_attributes.begin(),
!         eend = e_attributes.end();
! 
!       if ( ei != eend ) {
!         out << "edge [";
!         write_attributes(e_attributes, out);
!         out << "];" << std::endl;
!       }
      }
      GraphGraphAttributes g_attributes;
      GraphNodeAttributes n_attributes;
      GraphEdgeAttributes e_attributes;
--- 144,154 ----
        : g_attributes(gg), n_attributes(gn), e_attributes(ge) { }
  
      void operator()(std::ostream& out) const {
!       write_all_attributes(g_attributes, "graph", out);
!       write_all_attributes(n_attributes, "node", out);
!       write_all_attributes(e_attributes, "edge", out);
      }
+ 
      GraphGraphAttributes g_attributes;
      GraphNodeAttributes n_attributes;
      GraphEdgeAttributes e_attributes;
*************** namespace boost {
*** 196,207 ****
  
      template <class VorE>
      void operator()(std::ostream& out, const VorE& e) const {
!       if (!attributes[e].empty()) {
          out << "[";
          write_attributes(attributes[e], out);
          out << "]";
!       }
      }
      AttributeMap attributes;
    };
  
--- 190,213 ----
  
      template <class VorE>
      void operator()(std::ostream& out, const VorE& e) const {
!       this->write_attribute(out, attributes[e]);
!     }
! 
!   private:
!     template<typename AttributeSequence> 
!     void write_attribute(std::ostream& out, const AttributeSequence& seq) const
!     {
!      if (!attributes[e].empty()) {
          out << "[";
          write_attributes(attributes[e], out);
          out << "]";
!       }      
      }
+ 
+     void write_attribute(std::ostream&, detail::error_property_not_found) const
+     {
+     }
+ 
      AttributeMap attributes;
    };