Re: [Boost-users] [Graph] call of overloaded 'target(...)' is ambiguous

Subject: Re: [Boost-users] [Graph] call of overloaded 'target(...)' is ambiguous
From: Andrew Sutton (andrew.n.sutton_at_[hidden])
Date: 2008-12-08 09:26:33

> /usr/include/boost/graph/edmunds_karp_max_flow.hpp:232:   instantiated
> from 'typename boost::detail::edge_capacity_value<Graph, P, T,
> R>::type boost::edmunds_karp_max_flow(Graph&, typename
> boost::graph_traits<G>::vertex_descriptor, typename
> boost::graph_traits<G>::vertex_descriptor, const
> boost::bgl_named_params<P, T, R>&) [with Graph =
> FlowCapacitySQLDiGraph, P =
> edge_index_property_map<FlowCapacitySQLDiGraph, double>, T =
> boost::edge_residual_capacity_t, R = boost::no_property]'
> postgraph.cpp:1092:   instantiated from here
> /usr/include/boost/graph/visitors.hpp:176: error: call of overloaded
> 'target(FlowCapacitySQLDiGraph::edge_descriptor&, const
> boost::filtered_graph<FlowCapacitySQLDiGraph,
> boost::is_residual_edge<edge_index_property_map<FlowCapacitySQLDiGraph,
> double> >, boost::keep_all>&)' is ambiguous
> /usr/include/boost/graph/filtered_graph.hpp:322: note: candidates are:
> typename boost::filtered_graph_base<G>::vertex_descriptor
> boost::target(typename boost::filtered_graph_base<G>::edge_descriptor,
> const boost::filtered_graph_base<Graph>&) [with G =
> FlowCapacitySQLDiGraph]
> /usr/include/boost/graph/graph_traits.hpp:154: note:                 T
> std::target(std::pair<_ForwardIterator, _ForwardIterator>, const G&)
> [with T = unsigned int, G =
> boost::filtered_graph<FlowCapacitySQLDiGraph,
> boost::is_residual_edge<edge_index_property_map<FlowCapacitySQLDiGraph,
> double> >, boost::keep_all>]
> make: *** [postgraph.o] Error 1
>
>
I'm not sure what version of GCC you're using  - I assume it's GCC - but
you're ambiguity is coming from the fact that you probably have "using
namespace std" somewhere above this point in your code. The file
boost/graph/graph_traits.hpp puts a source() and target() function into the
standard namespace to provide an overload for a pair of vertex descriptors,
which is apparently need for some kinds of edge descriptor.

Using graph_traits<G>::edge_descriptor as the parameter type might work.
Explicitly calling boost::traget() will also probably work.

Andrew Sutton
andrew.n.sutton_at_[hidden]