Re: Q: Graphs. Sorting edges. Possible? How to?

From: loopylozzysdad (Richard_at_[hidden])
Date: 2002-11-06 18:56:22

Hi,

I did work out the answer to my own question. I can't explain how/why 
this works but by copying from the header files I ended up with the 
following changes to Jeremy's posted code...[1]

Good luck if you want it - please don't ask me to explain it!

Richard

[1]
Comment out from original ....
//struct ordered_set_by_nameS { };

//#ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
//namespace boost {
//	template <class ValueType>
//struct container_gen<ordered_set_by_nameS, ValueType> {
//	typedef std::multiset<ValueType, order_by_name<ValueType> > 
type;
//	};
//template <>
//struct parallel_edge_traits<ordered_set_by_nameS> {
//	typedef allow_parallel_edge_tag type;
//	};
//	}
//#endif

Replaced by .....
namespace boost {
        struct orderedmultisetS  { 
                template <class T>
        struct bind_ { typedef std::multiset<T, order_by_name<T> > 
type; };	// std::less<T>
                };

        BOOST_CONTAINER_SELECTOR(orderedmultisetS);

        template <>
                struct parallel_edge_traits<orderedmultisetS> { 
                        typedef disallow_parallel_edge_tag type; 
                        };
  
        }

--- In Boost-Users_at_y..., "loopylozzysdad" <loopylozzysdad_at_y...> wrote:
> Hi,
> 
> This answer (from Jeremy) is EXACTLY what I want! Sadly though I 
> am 'compilationally challenged' i.e. Visual C++ .NET chokes on it! 
I 
> don't understand the workaround in the header files enough to get 
it 
> working for me. Can anyone give me a clue about how to make the 
same 
> idea work in VC++.
> 
> Thanks - Richard Howells (LoopyLozzysDad at yahoo dot com)
> 
> --- In Boost-Users_at_y..., Jeremy Siek <jsiek_at_c...> wrote:
> > On Wed, 19 Jun 2002, stas_fomin wrote:
> > stas_f> > By using a custom container (use a std::set with your 
> custom
> > stas_f> comparison
> > stas_f> > function) for the EdgeList type, you can get the out-
> edges of each
> > stas_f> vertex
> > stas_f> > sorted, but there currently is not a way to get the 
> entire edge list
> > stas_f> > sorted.
> > stas_f> Ok... But BGL docs is less understandable (in comparison 
> with
> > stas_f> LEDAbook) for me (I know I am stupid).
> > 
> > Have you tried reading the BGL book?
> > 
> > stas_f> So, please, show me small example of declaration
> > stas_f> of some graph with out_edges sorted according to some 
> function...
> > 
> > Here you go. Also, this example is checked into the 
> libs/graph/example/
> > directory.
> > 
> > #include <boost/config.hpp>
> > #include <iostream>
> > #include <functional>
> > #include <string>
> > 
> > #include <boost/graph/adjacency_list.hpp>
> > #include <boost/graph/properties.hpp>
> > 
> > /*
> >   Sample output:
> > 
> >   0  --chandler--> 1   --joe--> 1
> >   1  --chandler--> 0   --joe--> 0   --curly--> 2   --dick--> 3   -
-
> dick-->
> > 3
> >   2  --curly--> 1   --tom--> 4
> >   3  --dick--> 1   --dick--> 1   --harry--> 4
> >   4  --tom--> 2   --harry--> 3
> > 
> >   name(0,1) = chandler
> > 
> >   name(0,1) = chandler
> >   name(0,1) = joe
> > 
> >  */
> > 
> > template <class StoredEdge>
> > struct order_by_name
> >   : public std::binary_function<StoredEdge,StoredEdge,bool>
> > {
> >   bool operator()(const StoredEdge& e1, const StoredEdge& e2) 
const 
> {
> >     // Order by target vertex, then by name.
> >     // std::pair's operator< does a nice job of implementing
> >     // lexicographical compare on tuples.
> >     return std::make_pair(e1.get_target(), boost::get
> (boost::edge_name,
> > e1))
> >       < std::make_pair(e2.get_target(), boost::get
> (boost::edge_name, e2));
> >   }
> > };
> > struct ordered_set_by_nameS { };
> > 
> > #ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
> > namespace boost {
> >   template <class ValueType>
> >   struct container_gen<ordered_set_by_nameS, ValueType> {
> >     typedef std::multiset<ValueType, order_by_name<ValueType> > 
> type;
> >   };
> >   template <>
> >   struct parallel_edge_traits<ordered_set_by_nameS> {
> >     typedef allow_parallel_edge_tag type;
> >   };
> > }
> > #endif
> > int
> > main()
> > {
> > #ifdef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
> >   std::cout << "This program requires partial specialization" <<
> > std::endl;
> > #else
> >   using namespace boost;
> >   typedef property<edge_name_t, std::string> EdgeProperty;
> >   typedef adjacency_list<ordered_set_by_nameS, vecS, undirectedS,
> >     no_property, EdgeProperty> graph_type;
> >   graph_type g;
> > 
> >   add_edge(0, 1, EdgeProperty("joe"), g);
> >   add_edge(1, 2, EdgeProperty("curly"), g);
> >   add_edge(1, 3, EdgeProperty("dick"), g);
> >   add_edge(1, 3, EdgeProperty("dick"), g);
> >   add_edge(2, 4, EdgeProperty("tom"), g);
> >   add_edge(3, 4, EdgeProperty("harry"), g);
> >   add_edge(0, 1, EdgeProperty("chandler"), g);
> > 
> >   property_map<graph_type, vertex_index_t>::type id = get
> (vertex_index,
> > g);
> >   property_map<graph_type, edge_name_t>::type name = get
(edge_name, 
> g);
> > 
> >   graph_traits<graph_type>::vertex_iterator i, end;
> >   graph_traits<graph_type>::out_edge_iterator ei, edge_end;
> >   for (boost::tie(i, end) = vertices(g); i != end; ++i) {
> >     std::cout << id[*i] << " ";
> >     for (boost::tie(ei, edge_end) = out_edges(*i, g); ei != 
> edge_end;
> > ++ei)
> >       std::cout << " --" << name[*ei] << "--> " << id[target(*ei, 
> g)] << "
> > ";
> >     std::cout << std::endl;
> >   }
> >   std::cout << std::endl;
> > 
> >   bool found;
> >   typedef graph_traits<graph_type> Traits;
> >   Traits::edge_descriptor e;
> >   Traits::out_edge_iterator e_first, e_last;
> > 
> >   tie(e, found) = edge(0, 1, g);
> >   if (found)
> >     std::cout << "name(0,1) = " << name[e] << std::endl;
> >   else
> >     std::cout << "not found" << std::endl;
> >   std::cout << std::endl;
> > 
> >   tie(e_first, e_last) = edge_range(0, 1, g);
> >   while (e_first != e_last)
> >     std::cout << "name(0,1) = " << name[*e_first++] << std::endl;
> > #endif
> >   return 0;
> > }
> > 
> > 
> > 
> > ------------------------------------------------------------------
--
> --
> >  Jeremy Siek                          
http://php.indiana.edu/~jsiek/
> >  Ph.D. Student, Indiana Univ. B'ton   email: jsiek_at_o...
> >  C++ Booster (http://www.boost.org)   office phone: [phone]
> > ------------------------------------------------------------------
--
> --