[Boost-users] Re: newbie: Graph library - bundled properties

23 Nov 2004

      You are not properly introducing your custom properties to boost.graph.
As an example of doing this correctly:

   using std::string;
   struct edgeStruct {
     int weight;
   };
   struct graphStruct {
     string name;
   };

   // create a tag for custom graph/edge properties
   enum graph_Datum_t { graph_Datum };
   enum edge_Datum_t { edge_Datum };
   namespace boost {
     BOOST_INSTALL_PROPERTY(graph,Datum);
     BOOST_INSTALL_PROPERTY(edge,Datum);
   }
   typedef boost::property GraphProperty;
   typedef boost::property EdgeIndex;
   typedef boost::property 
EdgeProperty;

   int
   main()
   {
     using namespace boost;
     typedef 
adjacency_list 
graph_t;
     graph_t g;

In order to access properties of a populated graph, it is necessary to 
employ property oriented boost.graph methods.

Your code example sugguests you expect things like operator[] methods 
where they aren't.  I too like to code in this fashion.
My solution was to make a "wrapper" class.
I've attached an example of such a class from my boost.graph using 
application.
It has operator[] method and standard iterator interfaces.

Note that this class holds a boost subgraph by reference and accesses 
properties only through the root subgraph.  I found this necessary in 
boost 1.31_0 because the properties of "derived" subgraphs had only 
default contructed property classes.  If this has been fixed in boost 
1.32_0, I'd like to know about it.

TC MA wrote:
...
After modifying it, still had some compile problems.
using std::string;
struct edgeStruct {
  int weight;
};
struct graphStruct {
  string name;
};
int
main()
{
  using namespace boost;
typedef adjacency_list
graph_t;
graph_t g;
  graph_t::vertex_descriptor v = *vertices(g).first;
  graph_t::edge_descriptor e = *out_edges(v, g).first;
  g[e].weight = 1;
  g[e].name = "graphname";
std::cout << "name: " << g[e].name << std::endl;
typedef subgraph subgraph_t;
subgraph_t sg;
  get_property(sg, graph_name) = "subgraph";
std::cout << "name: " << get_property(sg,
graph_name) << std::endl;
return exit_success;
}
# compile output is:
gcc-C++-action
/home/tcma/cpp/boosttcma/libs/graph/graph_property.test/gcc/debug/inlining-on/graph_property.o
/home/tcma/cpp/boosttcma/libs/graph/graph_property.cpp:
In function `int main()':
/home/tcma/cpp/boosttcma/libs/graph/graph_property.cpp:32:
error: 'struct edgeStruct' has no member named 'name'
/home/tcma/cpp/boosttcma/libs/graph/graph_property.cpp:34:
error: 'struct edgeStruct' has no member named 'name'
/home/tcma/cpp/boost_1_32_0/boost/graph/subgraph.hpp:
At global scope:
/home/tcma/cpp/boost_1_32_0/boost/graph/subgraph.hpp:
In instantiation of
`boost::subgraph':
/home/tcma/cpp/boosttcma/libs/graph/graph_property.cpp:39:
  instantiated from here
/home/tcma/cpp/boost_1_32_0/boost/graph/subgraph.hpp:249:
error: incomplete type
`boost::STATIC_ASSERTION_FAILURE<0u>' used in nested
name specifier
/home/tcma/cpp/boost_1_32_0/boost/graph/subgraph.hpp:249:
error: size of array has non-integral type `<type
error>'
/home/tcma/cpp/boost_1_32_0/boost/pending/detail/property.hpp:
In instantiation of
`boost::detail::build_property_tag_value_alist<graphStruct>':
/home/tcma/cpp/boost_1_32_0/boost/pending/property.hpp:63:
  instantiated from
`boost::property_value'
/home/tcma/cpp/boost_1_32_0/boost/graph/properties.hpp:235:
  instantiated from
`boost::graph_property'
/home/tcma/cpp/boosttcma/libs/graph/graph_property.cpp:40:
  instantiated from here
/home/tcma/cpp/boost_1_32_0/boost/pending/detail/property.hpp:94:
error: no type named `next_type' in `struct
graphStruct'
/home/tcma/cpp/boost_1_32_0/boost/pending/detail/property.hpp:95:
error: no type named `value_type' in `struct
graphStruct'
/home/tcma/cpp/boost_1_32_0/boost/pending/detail/property.hpp:96:
error: no type named `tag_type' in `struct
graphStruct'
/home/tcma/cpp/boost_1_32_0/boost/pending/detail/property.hpp:97:
error: no type named `next_type' in `struct
graphStruct'
/home/tcma/cpp/boost_1_32_0/boost/pending/detail/property.hpp:98:
error: no type named `tag_type' in `struct
graphStruct'
/home/tcma/cpp/boost_1_32_0/boost/pending/property.hpp:
In instantiation of
`boost::property_value':
/home/tcma/cpp/boost_1_32_0/boost/graph/properties.hpp:235:
  instantiated from
`boost::graph_property'
/home/tcma/cpp/boosttcma/libs/graph/graph_property.cpp:40:
  instantiated from here
/home/tcma/cpp/boost_1_32_0/boost/pending/property.hpp:63:
error: no type named `type' in `struct
boost::detail::build_property_tag_value_alist<graphStruct>'
/home/tcma/cpp/boost_1_32_0/boost/pending/property.hpp:64:
error: no type named `type' in `struct
boost::detail::build_property_tag_value_alist<graphStruct>'
/home/tcma/cpp/boost_1_32_0/boost/graph/properties.hpp:
In instantiation of
`boost::graph_property':
/home/tcma/cpp/boosttcma/libs/graph/graph_property.cpp:40:
  instantiated from here
/home/tcma/cpp/boost_1_32_0/boost/graph/properties.hpp:235:
error: no type named `type' in `struct
boost::property_value'
/home/tcma/cpp/boosttcma/libs/graph/graph_property.cpp:
In function `int main()':
/home/tcma/cpp/boosttcma/libs/graph/graph_property.cpp:40:
error: no matching function for call to
`get_property(main()::subgraph_t&,
boost::graph_name_t)'
/home/tcma/cpp/boosttcma/libs/graph/graph_property.cpp:42:
error: no matching function for call to
`get_property(main()::subgraph_t&,
boost::graph_name_t)'
/home/tcma/cpp/boost_1_32_0/boost/graph/subgraph.hpp:
In constructor `boost::subgraph<Graph>::subgraph()
[with Graph = main()::graph_t]':
/home/tcma/cpp/boosttcma/libs/graph/graph_property.cpp:39:
  instantiated from here
/home/tcma/cpp/boost_1_32_0/boost/graph/subgraph.hpp:106:
error: no matching function for call to
`boost::detail::error_property_not_found::error_property_not_found(int)'
/home/tcma/cpp/boost_1_32_0/boost/pending/detail/property.hpp:21:
note: candidates are:
boost::detail::error_property_not_found::error_property_not_found()
/home/tcma/cpp/boost_1_32_0/boost/pending/detail/property.hpp:21:
note:                
boost::detail::error_property_not_found::error_property_not_found(const
boost::detail::error_property_not_found&)
set -e
    "g++"   -c -Wall -ftemplate-depth-255   -g -O0
-Wno-inline  
-I"../../../bin/boost/libs/graph/example"   -I
"/home/tcma/cpp/boost_1_32_0"  -o
"/home/tcma/cpp/boosttcma/libs/graph/graph_property.test/gcc/debug/inlining-on/graph_property.o"
"/home/tcma/cpp/boosttcma/libs/graph/graph_property.cpp"
    "/usr/bin/objcopy" --set-section-flags
.debug_str=contents,debug
"/home/tcma/cpp/boosttcma/libs/graph/graph_property.test/gcc/debug/inlining-on/graph_property.o"
...failed gcc-C++-action
/home/tcma/cpp/boosttcma/libs/graph/graph_property.test/gcc/debug/inlining-on/graph_property.o...
...skipped
/home/tcma/cpp/boosttcma/libs/graph/graph_property
for lack of
graph_property.o...
...skipped
/home/tcma/cpp/boosttcma/libs/graph/graph_property.run
for lack of
/home/tcma/cpp/boosttcma/libs/graph/graph_property...
...failed updating 1 target...
...skipped 3 targets...
...
Date: Mon, 22 Nov 2004 20:36:07 -0500
From: Doug Gregor 
Subject: Re: [Boost-users] newbie: Graph library -
bundled properties
...
To: boost-users@lists.boost.org
Message-ID:
<0BEF9B5F-3CF0-11D9-84DF-000D932B7224@cs.indiana.edu>
...
Content-Type: text/plain; charset=US-ASCII;
format=flowed
...
On Nov 22, 2004, at 8:25 PM, TC MA wrote:
...
int
main()
{
 using namespace boost;
 using std::string;
Move this struct...
...
struct edgeStruct {
   int weight;
 };
outside of main, because of this error message:
/home/tcma/cpp/boosttcma/libs/graph/graph_property.cpp:21:
...
...
error: `main()::edgeStruct' uses local type
`main()::edgeStruct'
Doug
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[Boost-users] Re: newbie: Graph library - bundled properties

Jeffrey Holle