Question

我无法将boost::adjacency_list<setS, setS, undirectedS, int, float>转换或复制到boost::adjacency_list<vecS, vecS, undirectedS, int, float>，因此我可以将其用于boost::connected_components。我无法从外部API控制VertexList和EdgeList模板参数为boost::setS，因此我正在尝试解决此问题。

最小的例子

#include <vector>
#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/connected_components.hpp>
#include <boost/graph/copy.hpp>

typedef boost::adjacency_list<boost::setS, boost::setS, boost::undirectedS, uint32_t, float> AdjacencyList;
typedef boost::adjacency_list<boost::vecS, boost::vecS, boost::undirectedS, uint32_t, float> AdjacencyListWithVec;


typedef AdjacencyList::vertex_descriptor VertexID;


int main(int argc, char** argv)
{
    AdjacencyList adj;
    VertexID id_0 = boost::add_vertex(adj);
    VertexID id_1 = boost::add_vertex(adj);
    VertexID id_2 = boost::add_vertex(adj);
    VertexID id_3 = boost::add_vertex(adj);
    boost::add_edge(id_0, id_1, 1.0f, adj);
    boost::add_edge(id_2, id_3, 2.0f, adj);

    AdjacencyListWithVec adj_vec;

    boost::copy_graph(adj, adj_vec); // won't compile

    std::vector<uint32_t> component(4);
    size_t num_components = boost::connected_components (adj_vec, &component[0]);

}

g ++错误被截断

/usr/include/boost/graph/detail/adjacency_list.hpp: In instantiation of 'struct boost::adj_list_any_vertex_pa::bind_<boost::vertex_index_t, boost::adjacency_list<boost::setS, boost::setS, boost::undirectedS, int, float>, int>':
/usr/include/boost/graph/detail/adjacency_list.hpp:2613:12:   required from 'struct boost::detail::adj_list_choose_vertex_pa<boost::vertex_index_t, boost::adjacency_list<boost::setS, boost::setS, boost::undirectedS, int, float>, int>'
/usr/include/boost/graph/detail/adjacency_list.hpp:2750:12:   required from 'struct boost::adj_list_vertex_property_selector::bind_<boost::adjacency_list<boost::setS, boost::setS, boost::undirectedS, int, float>, int, boost::vertex_index_t>'
/usr/include/boost/graph/properties.hpp:201:12:   required from 'struct boost::detail::vertex_property_map<boost::adjacency_list<boost::setS, boost::setS, boost::undirectedS, int, float>, boost::vertex_index_t>'
/usr/include/boost/graph/properties.hpp:212:10:   required from 'struct boost::property_map<boost::adjacency_list<boost::setS, boost::setS, boost::undirectedS, int, float>, boost::vertex_index_t, void>'
/usr/include/boost/graph/detail/adjacency_list.hpp:1733:5:   required by substitution of 'template<class Config, class Base, class Property> typename boost::property_map<typename Config::graph_type, Property>::const_type boost::get(Property, const boost::adj_list_helper<Config, Base>&) [with Config = boost::detail::adj_list_gen<boost::adjacency_list<boost::setS, boost::setS, boost::undirectedS, int, float>, boost::setS, boost::setS, boost::undirectedS, int, float, boost::no_property, boost::listS>::config; Base = boost::undirected_graph_helper<boost::detail::adj_list_gen<boost::adjacency_list<boost::setS, boost::setS, boost::undirectedS, int, float>, boost::setS, boost::setS, boost::undirectedS, int, float, boost::no_property, boost::listS>::config>; Property = boost::vertex_index_t]'
/usr/include/boost/graph/copy.hpp:353:38:   required from 'void boost::copy_graph(const VertexListGraph&, MutableGraph&) [with VertexListGraph = boost::adjacency_list<boost::setS, boost::setS, boost::undirectedS, int, float>; MutableGraph = boost::adjacency_list<boost::vecS, boost::vecS, boost::undirectedS, int, float>]'
/my/file/and/line/num:   required from here
/usr/include/boost/graph/detail/adjacency_list.hpp:2543:29: error: forming reference to void
         typedef value_type& reference;
                             ^~~~~~~~~
/usr/include/boost/graph/detail/adjacency_list.hpp:2544:35: error: forming reference to void
         typedef const value_type& const_reference;
                                   ^~~~~~~~~~~~~~~
/usr/include/boost/graph/detail/adjacency_list.hpp:2547:47: error: forming reference to void
           <Graph, value_type, reference, Tag> type;
                                               ^~~~
/usr/include/boost/graph/detail/adjacency_list.hpp:2549:53: error: forming reference to void
           <Graph, value_type, const_reference, Tag> const_type;
                                                     ^~~~~~~~~~
...

In file included from/my/file:5:0:
/usr/include/boost/graph/copy.hpp: In instantiation of 'void boost::copy_graph(const VertexListGraph&, MutableGraph&) [with VertexListGraph = boost::adjacency_list<boost::setS, boost::setS, boost::undirectedS, int, float>; MutableGraph = boost::adjacency_list<boost::vecS, boost::vecS, boost::undirectedS, int, float>]':
/my/file/and/line/num:   required from here
/usr/include/boost/graph/copy.hpp:353:38: error: no matching function for call to 'get(boost::vertex_index_t, const boost::adjacency_list<boost::setS, boost::setS, boost::undirectedS, int, float>&)'
                                   get(vertex_index, g_in), orig2copy[0]),
                                   ~~~^~~~~~~~~~~~~~~~~~~~

Answer 1

未指定顶点贴图。创建一个很容易：

std::map<AdjacencyList::vertex_descriptor, int> index;
for (auto v : boost::make_iterator_range(boost::vertices(adj))) {
    index.insert(std::make_pair(v, index.size()));
}

AdjacencyListWithVec adj_vec;
boost::copy_graph(adj, adj_vec, boost::vertex_index_map(boost::make_assoc_property_map(index)));

Answer 2

来自documentation to boost::copy_graph：

命名参数

[...]

IN：vertex_index_map(VertexIndexMap i_map)


顶点索引映射类型必须是Readable Property Map的模型，并且必须将G的顶点描述符映射到半开范围[0，num_vertices(G)）中的整数。 / p>
默认值：get(vertex_index, G)。
    注意：如果您使用此默认设置，请确保您的图表具有内部vertex_index属性。例如，adjacency_list VertexList=listS vertex_index没有内部VertexList属性。

查看documentation for adjacency_list，我们看到：

如果图表的vecS为vertex_index_t，那么图表就会通过setS属性的属性映射访问内置顶点索引。

换句话说，您的限制因素是替代顶点列表表示与默认顶点索引映射不能很好地匹配。边列表表示不受影响。实际上，仅OutEdgeList使用typedef boost::adjacency_list<boost::setS, boost::vecS, boost::undirectedS, uint32_t, float> AdjacencyListWithVec;就可以正常工作，即以下工作：

VertexList

如果您的setS 为itertools，那么您必须提供自己的顶点索引贴图来处理它。不幸的是，我无法帮助你，但以下相关的SO问题可能会对你有所帮助：

将adjacency_list复制到不同的VertexList和EdgeList模板

最小的例子

g ++错误被截断

2 个答案:

命名参数