[BGL] Bundled properties and property maps
Hi, I've used BGL before for representing graphs, but this is my first time with an algorithm. I've been stuck for many hours trying to define a property map with bundled properties, I'd really appreciate some help. I'm using gcc4.3, boost 1.34. An example program and the compiler error are: ------------------------------------------------------------- #include <boost/graph/graph_traits.hpp> #include <boost/graph/adjacency_list.hpp> #include <boost/graph/astar_search.hpp> using namespace std; class Point { public: double p_[2]; }; struct EdgeProp { double cost; }; typedef boost::adjacency_list<boost::vecS, boost::vecS, boost::undirectedS, Point*, EdgeProp> Graph; typedef boost::graph_traits<Graph>::vertex_descriptor VertexRef; class AStarHeuristic : public boost::astar_heuristic<Graph, double> { public: double operator()( VertexRef vertex ) const {return 0.0;} }; // exception for termination struct FoundGoal {}; // // A* Visitor that terminates when we reach the goal // class AStarVisitor : public boost::default_astar_visitor { public: AStarVisitor( const VertexRef &goal ) : goal_(goal) {} template <class Graph> void examine_vertex( VertexRef vertex, Graph &g ) { if( vertex == goal_ ) throw FoundGoal(); } private: VertexRef goal_; }; bool searchThroughGraph( const Graph &graph, VertexRef start, VertexRef goal, std::vector<VertexRef> &shortestPath ) { AStarHeuristic aStarHeuristic; AStarVisitor aStarVisitor( goal ); typedef boost::property_map<Graph, double EdgeProp::*>::type EdgeWeightMap; EdgeWeightMap edgeWeightMap = get(&EdgeProp::cost, graph); std::vector<VertexRef> predecessors(num_vertices(graph)); try { astar_search( graph, start, aStarHeuristic, boost::weight_map(edgeWeightMap). predecessor_map(&predecessors[0]). visitor(aStarVisitor) ); } catch ( const FoundGoal& ) { shortestPath.clear(); for ( VertexRef vertex = goal;; vertex = predecessors[vertex] ) { shortestPath.push_back( vertex ); if ( predecessors[vertex]==vertex ) break; } std::reverse( shortestPath.begin(), shortestPath.end() ); return true; } // If we get to here, we couldn't reach the goal return false; } int main() { Graph graph; std::vector<VertexRef> path; searchThroughGraph(graph,0,1,path); return 0; } ------------------------------------------------------------- /home/a.brooks/shh/src/libs/prm/test/stupid.cpp: In function ‘bool searchThroughGraph(const Graph&, VertexRef, VertexRef, std::vector<unsigned int, std::allocator<unsigned int> >&)’: /home/a.brooks/shh/src/libs/prm/test/stupid.cpp:64: error: conversion from ‘boost::bundle_property_map<const boost::adjacency_list<boost::vecS, boost::vecS, boost::undirectedS, Point*, EdgeProp, boost::no_property, boost::listS>, boost::detail::edge_desc_impl<boost::undirected_tag, unsigned int>, EdgeProp, const double>’ to non-scalar type ‘searchThroughGraph(const Graph&, VertexRef, VertexRef, std::vector<unsigned int, std::allocator<unsigned int> >&)::EdgeWeightMap’ requested ------------------------------------------------------------- Does anyone know what might be wrong? More generally, I'm a bit mystefied by the "<Graph, double EdgeProp::*>::type" syntax -- can anyone give me any pointers about what this syntax means, or where I can look it up? (googling for colon-colon-star doesn't help much). I also tried pattern-matching from the documentation page about bundled properties (the weight_map(get(&Highway::miles, map)) example) but couldn't get this to compile either. Is this example correct? Thanks very much in advance, Alex
Sorry, I neglected to point out the line that doesn't compile. It's marked below: typedef boost::property_map<Graph, double EdgeProp::*>::type EdgeWeightMap; // The following line fails to compile EdgeWeightMap edgeWeightMap = get(&EdgeProp::cost, graph); Thanks again, Alex
Does anyone know what might be wrong?
Yes... The type of the property map generated by the get() function is built for a *const* graph (since you're passing graph as const&), but your're declaring EdgeWeightMap over a non-const graph (as in property_map<Graph, ...>). I think the most appropriate fix is to change the definition of EdgeWeightMap to typedef boost::property_map<const Graph, double const EdgeProp::*>::type EdgeWeightMap; Another solution might be to always pass by non-const reference, but that's not really good style. I would have thought that property_map was appropriately specialized for const/non-const versions. I'll have to look into it. More generally, I'm a bit mystefied by the "<Graph, double
EdgeProp::*>::type" syntax -- can anyone give me any pointers about what this syntax means, or where I can look it up? (googling for colon-colon-star doesn't help much). I also tried pattern-matching from the documentation page about bundled properties (the weight_map(get(&Highway::miles, map)) example) but couldn't get this to compile either. Is this example correct?
It's pointer-to-member syntax. Read from right to left You're saying that the type is a "pointer to a member of EdgeProp that is of type double." Or in this case, a pointer to a const EdgeProp that's a double. Andrew Sutton andrew.n.sutton@gmail.com
Hi Andrew, Thanks very much for the help, I've got it working now. I had to use a non-const reference though. Here are the options I tried: // Option A: Graph &nonConstGraph = const_cast<Graph&>(graph); typedef boost::property_map<Graph, double EdgeProp::*>::type EdgeWeightMap; EdgeWeightMap edgeWeightMap = get(&EdgeProp::cost, nonConstGraph); // Option B: // typedef boost::property_map<Graph, double const EdgeProp::*>::type EdgeWeightMap; // EdgeWeightMap edgeWeightMap = get(&EdgeProp::cost, graph); Option A works, but is a bit ugly. Option B is what you suggested, but it gives the following error: /home/a.brooks/shh/src/libs/prm/test/stupid.cpp:70: error: conversion from 'boost::bundle_property_map<const boost::adjacency_list<boost::vecS, boost::vecS, boost::undirectedS, Point*, EdgeProp, boost::no_property, boost::listS>, boost::detail::edge_desc_impl<boost::undirected_tag, unsigned int>, EdgeProp, const double>' to non-scalar type 'searchThroughGraph(const Graph&, VertexRef, VertexRef, std::vector<unsigned int, std::allocator<unsigned int> >&)::EdgeWeightMap' requested Do I also need to modify the 'get()' line?
It's pointer-to-member syntax. Read from right to left You're saying that the type is a "pointer to a member of EdgeProp that is of type double." Or in this case, a pointer to a const EdgeProp that's a double.
Awesome, thanks for the pointer. Cheers, Alex
// typedef boost::property_map<Graph, double const EdgeProp::*>::type EdgeWeightMap; // EdgeWeightMap edgeWeightMap = get(&EdgeProp::cost, graph);
Option A works, but is a bit ugly. Option B is what you suggested, but it gives the following error:
Gotta a const Graph also: property_map<const Graph, double const EdgeProp::*> Andrew Sutton andrew.n.sutton@gmail.com
Gotta a const Graph also:
property_map<const Graph, double const EdgeProp::*>
This line compiles now, but I get a new compile error from the astar_search line. The important bits are: typedef boost::property_map<const Graph, double const EdgeProp::*>::type EdgeWeightMap; EdgeWeightMap edgeWeightMap = get(&EdgeProp::cost, graph); std::vector<VertexRef> predecessors(num_vertices(graph)); astar_search( graph, start, aStarHeuristic, boost::weight_map(edgeWeightMap). predecessor_map(&predecessors[0]). visitor(aStarVisitor) ); The error is: /usr/include/c++/4.3/bits/allocator.h:84: instantiated from 'std::allocator<const double>' /usr/include/c++/4.3/bits/stl_vector.h:75: instantiated from 'std::_Vector_base<const double, std::allocator<const double> >' /usr/include/c++/4.3/bits/stl_vector.h:176: instantiated from 'std::vector<const double, std::allocator<const double> >' /usr/include/boost/graph/astar_search.hpp:360: instantiated from 'void boost::detail::astar_dispatch1(VertexListGraph&, typename boost::graph_traits<G>::vertex_descriptor, AStarHeuristic, CostMap, DistanceMap, WeightMap, IndexMap, ColorMap, const Params&) [with VertexListGraph = const boost::adjacency_list<boost::vecS, boost::vecS, boost::undirectedS, Point*, EdgeProp, boost::no_property, boost::listS>, AStarHeuristic = AStarHeuristic, CostMap = boost::detail::error_property_not_found, DistanceMap = boost::detail::error_property_not_found, WeightMap = boost::bundle_property_map<const boost::adjacency_list<boost::vecS, boost::vecS, boost::undirectedS, Point*, EdgeProp, boost::no_property, boost::listS>, boost::detail::edge_desc_impl<boost::undirected_tag, unsigned int>, EdgeProp, const double>, IndexMap = boost::vec_adj_list_vertex_id_map<boost::property<boost::vertex_bundle_t, Point*, boost::no_property>, unsigned int>, ColorMap = boost::detail::error_property_not_found, Params = boost::bgl_named_params<AStarVisitor, boost::graph_visitor_t, boost::bgl_named_params<unsigned int*, boost::vertex_predecessor_t, boost::bgl_named_params<boost::bundle_property_map<const boost::adjacency_list<boost::vecS, boost::vecS, boost::undirectedS, Point*, EdgeProp, boost::no_property, boost::listS>, boost::detail::edge_desc_impl<boost::undirected_tag, unsigned int>, EdgeProp, const double>, boost::edge_weight_t, boost::no_property> > >]' /usr/include/boost/graph/astar_search.hpp:394: instantiated from 'void boost::astar_search(VertexListGraph&, typename boost::graph_traits<G>::vertex_descriptor, AStarHeuristic, const boost::bgl_named_params<P, T, R>&) [with VertexListGraph = const boost::adjacency_list<boost::vecS, boost::vecS, boost::undirectedS, Point*, EdgeProp, boost::no_property, boost::listS>, AStarHeuristic = AStarHeuristic, P = AStarVisitor, T = boost::graph_visitor_t, R = boost::bgl_named_params<unsigned int*, boost::vertex_predecessor_t, boost::bgl_named_params<boost::bundle_property_map<const boost::adjacency_list<boost::vecS, boost::vecS, boost::undirectedS, Point*, EdgeProp, boost::no_property, boost::listS>, boost::detail::edge_desc_impl<boost::undirected_tag, unsigned int>, EdgeProp, const double>, boost::edge_weight_t, boost::no_property> >]' /home/a.brooks/shh/src/libs/prm/test/stupid.cpp:83: instantiated from here /usr/include/c++/4.3/ext/new_allocator.h:82: error: 'const _Tp* __gnu_cxx::new_allocator<_Tp>::address(const _Tp&) const [with _Tp = const double]' cannot be overloaded /usr/include/c++/4.3/ext/new_allocator.h:79: error: with '_Tp* __gnu_cxx::new_allocator<_Tp>::address(_Tp&) const [with _Tp = const double]' Any other ideas? Thanks again, Alex
Hi Alex, I was able to compile your original code by changing the line typedef boost::property_map<Graph, double EdgeProp::*>::type EdgeWeightMap; to typedef boost::property_map<Graph, double EdgeProp::*>::const_type EdgeWeightMap; hope this will help, Dmitry Alex Brooks escribió:
Gotta a const Graph also:
property_map<const Graph, double const EdgeProp::*>
Any other ideas?
Thanks again,
Alex
I was able to compile your original code by changing the line typedef boost::property_map<Graph, double EdgeProp::*>::type EdgeWeightMap; to typedef boost::property_map<Graph, double EdgeProp::*>::const_type EdgeWeightMap;
That's right! I had completely forgotten about the const_type member... Good catch Dmitry. Andrew Sutton andrew.n.sutton@gmail.com
/usr/include/c++/4.3/ext/new_allocator.h:82: error: 'const _Tp* __gnu_cxx::new_allocator<_Tp>::address(const _Tp&) const [with _Tp = const double]' cannot be overloaded /usr/include/c++/4.3/ext/new_allocator.h:79: error: with '_Tp* __gnu_cxx::new_allocator<_Tp>::address(_Tp&) const [with _Tp = const double]'
Not good... astar passes its graph by non-const reference so when it declares: typedef typename property_traits<WeightMap>::value_type D; typename std::vector<D>::size_type D is apparently const double, and std::vector<const double> doesn't seem to work too well - not to mention the fact that you probably want to assign values to elemetns of that vector :) I guess your only solution is to pass the graph by non-const reference. This may be a bug, but I'm not entirely sure. Andrew Sutton andrew.n.sutton@gmail.com
Hi Andrew/Dmitry, Thanks again for the help. I guess I'll stick with the const-cast. Cheers, Alex
Alex Brooks wrote:
Gotta a const Graph also:
property_map<const Graph, double const EdgeProp::*>
This line compiles now, but I get a new compile error from the astar_search line. The important bits are:
typedef boost::property_map<const Graph, double const EdgeProp::*>::type EdgeWeightMap; EdgeWeightMap edgeWeightMap = get(&EdgeProp::cost, graph);
std::vector<VertexRef> predecessors(num_vertices(graph)); astar_search( graph, start, aStarHeuristic, boost::weight_map(edgeWeightMap). predecessor_map(&predecessors[0]). visitor(aStarVisitor) );
The error is:
/usr/include/c++/4.3/bits/allocator.h:84: instantiated from 'std::allocator<const double>' /usr/include/c++/4.3/bits/stl_vector.h:75: instantiated from 'std::_Vector_base<const double, std::allocator<const double> >' /usr/include/c++/4.3/bits/stl_vector.h:176: instantiated from 'std::vector<const double, std::allocator<const double> >' /usr/include/boost/graph/astar_search.hpp:360: instantiated from 'void boost::detail::astar_dispatch1(VertexListGraph&, typename boost::graph_traits<G>::vertex_descriptor, AStarHeuristic, CostMap, DistanceMap, WeightMap, IndexMap, ColorMap, const Params&) [with VertexListGraph = const boost::adjacency_list<boost::vecS, boost::vecS, boost::undirectedS, Point*, EdgeProp, boost::no_property, boost::listS>, AStarHeuristic = AStarHeuristic, CostMap = boost::detail::error_property_not_found, DistanceMap = boost::detail::error_property_not_found, WeightMap = boost::bundle_property_map<const boost::adjacency_list<boost::vecS, boost::vecS, boost::undirectedS, Point*, EdgeProp, boost::no_property, boost::listS>, boost::detail::edge_desc_impl<boost::undirected_tag, unsigned int>, EdgeProp, const double>, IndexMap = boost::vec_adj_list_vertex_id_map<boost::property<boost::vertex_bundle_t, Point*, boost::no_property>, unsigned int>, ColorMap = boost::detail::error_property_not_found, Params = boost::bgl_named_params<AStarVisitor, boost::graph_visitor_t, boost::bgl_named_params<unsigned int*, boost::vertex_predecessor_t, boost::bgl_named_params<boost::bundle_property_map<const boost::adjacency_list<boost::vecS, boost::vecS, boost::undirectedS, Point*, EdgeProp, boost::no_property, boost::listS>, boost::detail::edge_desc_impl<boost::undirected_tag, unsigned int>, EdgeProp, const double>, boost::edge_weight_t, boost::no_property> > >]' /usr/include/boost/graph/astar_search.hpp:394: instantiated from 'void boost::astar_search(VertexListGraph&, typename boost::graph_traits<G>::vertex_descriptor, AStarHeuristic, const boost::bgl_named_params<P, T, R>&) [with VertexListGraph = const boost::adjacency_list<boost::vecS, boost::vecS, boost::undirectedS, Point*, EdgeProp, boost::no_property, boost::listS>, AStarHeuristic = AStarHeuristic, P = AStarVisitor, T = boost::graph_visitor_t, R = boost::bgl_named_params<unsigned int*, boost::vertex_predecessor_t, boost::bgl_named_params<boost::bundle_property_map<const boost::adjacency_list<boost::vecS, boost::vecS, boost::undirectedS, Point*, EdgeProp, boost::no_property, boost::listS>, boost::detail::edge_desc_impl<boost::undirected_tag, unsigned int>, EdgeProp, const double>, boost::edge_weight_t, boost::no_property> >]' /home/a.brooks/shh/src/libs/prm/test/stupid.cpp:83: instantiated from here /usr/include/c++/4.3/ext/new_allocator.h:82: error: 'const _Tp* __gnu_cxx::new_allocator<_Tp>::address(const _Tp&) const [with _Tp = const double]' cannot be overloaded /usr/include/c++/4.3/ext/new_allocator.h:79: error: with '_Tp* __gnu_cxx::new_allocator<_Tp>::address(_Tp&) const [with _Tp = const double]'
Any other ideas?
Thanks again,
Alex
I'm having the same problem though mine (with MSVC9) says: error C2678: binary '=': no operator found which takes a left-hand operand of type 'const Weight' (or there is no acceptable conversion) c:\program files\boost\boost_1_37_0\boost\property_map.hpp 161 A follow-up would be greatly appreciated. Thanks, Geoff
Geoff Hilton wrote:
I'm having the same problem though mine (with MSVC9) says:
error C2678: binary '=': no operator found which takes a left-hand operand of type 'const Weight' (or there is no acceptable conversion) c:\program files\boost\boost_1_37_0\boost\property_map.hpp 161
A follow-up would be greatly appreciated.
Thanks, Geoff
You can try to use boost::remove_const<Weight>::type Regards, Dmitry
Dmitry Bufistov wrote:
Geoff Hilton wrote:
I'm having the same problem though mine (with MSVC9) says:
error C2678: binary '=': no operator found which takes a left-hand operand of type 'const Weight' (or there is no acceptable conversion) c:\program files\boost\boost_1_37_0\boost\property_map.hpp 161
A follow-up would be greatly appreciated.
Thanks, Geoff
You can try to use boost::remove_const<Weight>::type
Regards, Dmitry
I appreciate your suggestion, but the reason I'm getting the error is because I'm trying to make the code const-correct, until yesterday code that raised this issue would have the graph parameter be rendered non-const as a temporary "fix", but that's not good style, I'm looking to remedy this by making the code const-correct now. :) If there's no other solution then I'll revert the const-correctedness changes until there is one, but I have a hard time believing this to be the case. Thanks, Geoff
Dmitry Bufistov wrote:
Geoff Hilton wrote:
I'm having the same problem though mine (with MSVC9) says:
error C2678: binary '=': no operator found which takes a left-hand operand of type 'const Weight' (or there is no acceptable conversion) c:\program files\boost\boost_1_37_0\boost\property_map.hpp 161
A follow-up would be greatly appreciated.
Thanks, Geoff
You can try to use boost::remove_const<Weight>::type
Regards, Dmitry
To help things along, here's the code in question: Note: graph variable is of type const Graph&. const boost::property_map<Graph, Weight EdgeProp::*>::const_type eprop = boost::get(&EdgeProp::weight, graph); const boost::property_map<Graph, boost::vertex_index_t>::const_type vindex = boost::get(boost::vertex_index, graph); const vertex_descriptor firstVertex = *GetGraphBeginVertexIterator(graph); PredecessorMap preds = PredecessorMap(numVertices); DistanceMap dists = DistanceMap(numVertices); boost::bellman_ford_shortest_paths(graph, numVertices, weight_map(eprop) .predecessor_map(boost::make_iterator_property_map(preds.begin(), vindex)) .distance_map(boost::make_iterator_property_map(dists.begin(), vindex)) .root_vertex(firstVertex) .distance_combine(Combiner()) .distance_compare(Comparer(currentOffset)) ); Also, my Weight type has an explicit constructor which takes a POD convertible to 0, a requirement imposed it seems by line 155 of bellman_ford_shortest_paths.hpp. Why doesn't the algorithm take a weight of value zero as a parameter and use it instead? Anyway, because of this explicit constructor I've added a (typical) assignment operator (not sure if this is relevant, but I'm mentioning it just in case). I should also note that out of curiosity I commented out line 103 of bellman_ford_shortest_paths.hpp which is: function_requires<ReadablePropertyMapConcept<WeightMap, Edge> >(); Commenting out the above line allows my code as written above to compile, otherwise it fails with the error written in my original response (quoted above). Whether the compiled code (with line 103 commented out) functions as expected I don't know, I haven't tested it. Thanks, Geoff
Geoff Hilton escribió:
Note: graph variable is of type const Graph&.
[skip]
Also, my Weight type has an explicit constructor which takes a POD convertible to 0, a requirement imposed it seems by line 155 of bellman_ford_shortest_paths.hpp. Why doesn't the algorithm take a weight of value zero as a parameter and use it instead?
Anyway, because of this explicit constructor I've added a (typical) assignment operator (not sure if this is relevant, but I'm mentioning it just in case).
I should also note that out of curiosity I commented out line 103 of bellman_ford_shortest_paths.hpp which is:
function_requires<ReadablePropertyMapConcept<WeightMap, Edge> >();
Commenting out the above line allows my code as written above to compile, otherwise it fails with the error written in my original response (quoted above). Whether the compiled code (with line 103 commented out) functions as expected I don't know, I haven't tested it.
Thanks, Geoff
It looks like the problem is with template <class PMap, class Key> struct ReadablePropertyMapConcept; The following code fails to compile: #include <boost/graph/graph_concepts.hpp> #include <boost/graph/adjacency_list.hpp> using namespace boost; struct EdgeProp { double weight; }; typedef boost::adjacency_list<vecS, vecS, directedS, no_property, EdgeProp > graph_t; int main() { typedef boost::property_map<graph_t, double EdgeProp::*>::const_type WeightMap; typedef boost::graph_traits<graph_t>::edge_descriptor Edge; function_requires<ReadablePropertyMapConcept<WeightMap, Edge> >(); } You may try to change the boost/property_map.hpp as follows: (in the version 1.37 the line number is 165) typename typename property_traits<PMap>::value_type val; to the typename remove_const<typename property_traits<PMap>::value_type>::type val; Does it work for you? Regards, Dmitry
Dmitry Bufistov wrote:
Geoff Hilton escribió:
Note: graph variable is of type const Graph&.
[skip]
Also, my Weight type has an explicit constructor which takes a POD convertible to 0, a requirement imposed it seems by line 155 of bellman_ford_shortest_paths.hpp. Why doesn't the algorithm take a weight of value zero as a parameter and use it instead?
Anyway, because of this explicit constructor I've added a (typical) assignment operator (not sure if this is relevant, but I'm mentioning it just in case).
I should also note that out of curiosity I commented out line 103 of bellman_ford_shortest_paths.hpp which is:
function_requires<ReadablePropertyMapConcept<WeightMap, Edge> >();
Commenting out the above line allows my code as written above to compile, otherwise it fails with the error written in my original response (quoted above). Whether the compiled code (with line 103 commented out) functions as expected I don't know, I haven't tested it.
Thanks, Geoff
It looks like the problem is with template <class PMap, class Key> struct ReadablePropertyMapConcept;
The following code fails to compile:
#include <boost/graph/graph_concepts.hpp> #include <boost/graph/adjacency_list.hpp>
using namespace boost; struct EdgeProp { double weight; };
typedef boost::adjacency_list<vecS, vecS, directedS, no_property, EdgeProp > graph_t; int main() { typedef boost::property_map<graph_t, double EdgeProp::*>::const_type WeightMap; typedef boost::graph_traits<graph_t>::edge_descriptor Edge; function_requires<ReadablePropertyMapConcept<WeightMap, Edge> >(); }
You may try to change the boost/property_map.hpp as follows: (in the version 1.37 the line number is 165) typename typename property_traits<PMap>::value_type val; to the typename remove_const<typename property_traits<PMap>::value_type>::type val;
Does it work for you?
Regards, Dmitry
Thanks Dmitry, it does work! I do wonder though, isn't there a better fix? What about specializing ReadablePropertyMapConcept specifically for const properties, or does that not make sense with concept classes? I'm okay with modifying BGL code, but the remove_const makes me feel dirty. This sounds like something that should be brought up with BGL maintainers... Geoff
Geoff Hilton escribió:
(in the version 1.37 the line number is 165) typename typename property_traits<PMap>::value_type val; to the typename remove_const<typename property_traits<PMap>::value_type>::type val;
Does it work for you?
Regards, Dmitry
Thanks Dmitry, it does work! I do wonder though, isn't there a better fix? What about specializing ReadablePropertyMapConcept specifically for const properties, or does that not make sense with concept classes? I'm okay with modifying BGL code, but the remove_const makes me feel dirty.
This sounds like something that should be brought up with BGL maintainers...
Geoff
I believe that something is bad with the const version of bundled_properties. Andrew, what do you think? Dmitry
Thanks Dmitry, it does work! I do wonder though, isn't there a better fix?
What about specializing ReadablePropertyMapConcept specifically for const properties, or does that not make sense with concept classes? I'm okay with modifying BGL code, but the remove_const makes me feel dirty.
This sounds like something that should be brought up with BGL maintainers...
Geoff
I believe that something is bad with the const version of bundled_properties. Andrew, what do you think?
This is the only report - to my knowledge - of this kind of problem. I'm not entirely that the best solution is to change the BGL. I'll have to take a good look tomorrow morning. Andrew Sutton andrew.n.sutton@gmail.com
Andrew Sutton wrote:
Thanks Dmitry, it does work! I do wonder though, isn't there a better fix? What about specializing ReadablePropertyMapConcept specifically for const properties, or does that not make sense with concept classes? I'm okay with modifying BGL code, but the remove_const makes me feel dirty.
This sounds like something that should be brought up with BGL maintainers...
Geoff
I believe that something is bad with the const version of bundled_properties. Andrew, what do you think?
This is the only report - to my knowledge - of this kind of problem. I'm not entirely that the best solution is to change the BGL. I'll have to take a good look tomorrow morning.
Andrew Sutton andrew.n.sutton@gmail.com
Merry Christmas, Happy New Year and all that! Any progress? Thanks, Geoff
participants (4)
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Alex Brooks -
Andrew Sutton -
Dmitry Bufistov -
Geoff Hilton