Boost Graph 通过 vertex_descriptor 访问属性

2021-12-24 00:00:00 graph c++ boost boost-graph

我有自定义的顶点和边属性

I have my custom vertex and edge properties

namespace boost { 
    enum vertex_diagonal_t{vertex_diagonal = 999};
    BOOST_INSTALL_PROPERTY(vertex, diagonal);
}
namespace boost { 
    enum edge_dominance_t{edge_dominance = 998};
    BOOST_INSTALL_PROPERTY(edge, dominance);
}

我使用 boost::property

typedef boost::adjacency_list<
      boost::listS, 
      boost::vecS,
      boost::bidirectionalS,
      boost::property<boost::vertex_diagonal_t, const khut::diagonal*>,
      boost::property<boost::edge_dominance_t,  float>
    > diagonal_dominance_graph;
typedef boost::property_map<diagonal_dominance_graph, boost::vertex_diagonal_t>::type diagonal_map_type;
typedef boost::property_map<diagonal_dominance_graph, boost::edge_dominance_t>::type  dominance_map_type;

现在我想遍历我自己的容器并添加顶点

Now I want to loop through my own containers and add vertex

diagonal_dominance_graph graph;
  for(storage_type::const_iterator i = repo_begining.begin(); i != repo_begining.end(); ++i){
    diagonal_dominance_graph::vertex_descriptor dia_vertex = boost::add_vertex(graph);

    //>> ?? HOW CAN I write Properties to dia_vertex HERE ?

    //boost::property<boost::vertex_diagonal_t, const khut::diagonal*> p;
    //boost::put(p, dia_vertex);

  }

我没有得到的是如何通过 vertex_descriptor 设置顶点的属性.可能是我缺少一个简单的功能.

What I am not getting is How can I set properties of a vertex through vertex_descriptor. may be I am missing a simple function.

拜托，我不需要任何让 BGL 变得更加复杂的东西，或者在我的示例中清理和重组类型的东西.我只需要知道如何通过 vertex_descriptor 或 edge_descriptor

Please I don't need anything that makes BGL even more complex, or something that cleans and restructures the types in my example. I just need to know how to read/write properties through a vertex_descriptor or edge_descriptor

推荐答案

您正在使用属性列表:它们是 此处记录.

You're using property lists: they're documented here.

所以在你的例子中，你会使用

So in your example, you'd use

diagonal_map_type  vp = get(boost::vertex_diagonal, graph);

using storage_type = std::vector<int>;
storage_type repo_begining(10);

for(storage_type::const_iterator i = repo_begining.begin(); i != repo_begining.end(); ++i) {
    diagonal_dominance_graph::vertex_descriptor dia_vertex = boost::add_vertex(graph);


    khut::diagonal* v = nullptr;
    boost::put(vp, dia_vertex, v);
}

// likewise for edges
dominance_map_type ep = get(boost::edge_dominance, graph);

看到它在 Coliru 上直播

See it Live On Coliru

完全相同的文档页面说:

The very same documentation page says:

注意:Boost 图库支持两种可互换的方法来指定内部属性:捆绑属性和属性列表.前者更易于使用且需要更少的努力，而后者与旧的、损坏的编译器兼容，并且向后兼容 1.32.0 之前的 Boost 版本.如果您绝对需要这些兼容性功能，请继续阅读以了解属性列表.否则，我们强烈建议您阅读捆绑属性机制.

NOTE: The Boost Graph Library supports two interchangeable methods for specifying interior properties: bundled properties and property lists. The former is easier to use and requires less effort, whereas the latter is compatible with older, broken compilers and is backward-compatible with Boost versions prior to 1.32.0. If you absolutely require these compatibility features, read on to learn about property lists. Otherwise, we strongly suggest that you read about the bundled properties mechanism.

Boost 1.32 日期超过 10 年！所以，我建议捆绑属性:

Boost 1.32 dates over 10 years ago! So, I'd suggest bundled properties:

生活在 Coliru

#include <boost/graph/adjacency_list.hpp>

namespace khut {
    struct diagonal { };

    struct MyVertexProperties {
        diagonal const* diag_ptr;
    };

    struct MyEdgeProperties {
        float dominance;
    };
}

typedef boost::adjacency_list<
      boost::listS, 
      boost::vecS,
      boost::bidirectionalS,
      khut::MyVertexProperties,
      khut::MyEdgeProperties
    > diagonal_dominance_graph;

#include <iostream>


int main() {
    using namespace boost;

    diagonal_dominance_graph g;

    khut::diagonal d1, d2;
    {
        auto v1 = add_vertex(khut::MyVertexProperties { &d1 }, g);
        auto v2 = add_vertex(khut::MyVertexProperties { &d2 }, g);

        /*auto e1 = */add_edge(v1, v2, khut::MyEdgeProperties { 42.31415926 }, g);
    }

    for(diagonal_dominance_graph::vertex_descriptor vd : make_iterator_range(vertices(g)))
        std::cout << "Is diagonal d1? " << std::boolalpha << (&d1 == g[vd].diag_ptr) << "
";
    for(diagonal_dominance_graph::edge_descriptor ed : make_iterator_range(edges(g)))
        std::cout << "Edge dominance: " << g[ed].dominance << "
";
}

印刷品

Is diagonal d1? true
Is diagonal d1? false
Edge dominance: 42.3142

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