C++ 使用boost:：copy_graph从网格_图复制到邻接_列表

我正在使用boost graph库，并尝试初始化一个

MutableGraph

，以网格的形式开始生活。 边缘会在以后的生活中添加和删除，所以我认为

邻接列表

是正确的选择

我对BGL的阅读表明，使用这些边初始化BGL的明智方法是利用

boost:：grid\u graph

boost:：copy_graph

从一个

boost:：grid_graph

复制，它可以为我免费创建所有初始边。 我认为这是有意义的-

copy\u graph

将

VertexListGraph

的模型复制到

MutableGraph

的模型，这正是我所拥有的

我最初尝试使用双参数版本的

copy\u graph

，模糊地希望在剩下的默认值中会发生一些合理的事情。事实并非如此，

grid\u graph

（出于我无法完全理解的原因）似乎没有一个工具可以使用带有边或顶点的

PropertyMap

s，因此默认的

vertex\u copy

和

edge\u copy

复制属性失败（出现编译器错误）

由于2参数版本显然不合适，我继续并尝试实现我自己的二进制操作符来复制顶点和边。即使是“无操作”拷贝，它也不能像我希望的那样工作（即，它不能编译）

我总结了一个最基本的工作示例来说明问题：

#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/grid_graph.hpp>
#include <boost/graph/copy.hpp>

struct Position {
  int x, y;
};

struct VertexProperties {
  Position pos;
};

typedef boost::adjacency_list<boost::vecS, boost::listS, boost::undirectedS, 
                      VertexProperties> Graph;

struct MyCopy {
  template <typename S, typename D>
  void operator()(const S& /*src*/, D& /*dest*/) {
    // Nothing for now, deduced types to try and just make it compile
    // TODO: set values for pos to reflect position on grid.
  }
};

int main() {
    boost::array<std::size_t, 2> lengths = { { 3, 3 } };
    boost::grid_graph<2> grid(lengths);

    Graph graph;
    MyCopy copier;
    // Using 3-Arg version of copy_graph so we can specify a custom way of copying to create the properties
    boost::copy_graph(grid,graph,boost::bgl_named_params<MyCopy,boost::vertex_copy_t,
                                 boost::bgl_named_params<MyCopy,boost::edge_copy_t> >(copier));
}

#包括
#包括
#包括
结构位置{
int x，y；
};
结构顶点属性{
位置pos；
};
typedef boost:：邻接列表图；
结构霉菌病{
模板
void运算符（）（常数S&/*src*/，D&/*dest*/）{
//现在没什么，只是让它编译
//TODO：设置pos值以反映网格上的位置。
}
};
int main（）{
数组长度={3,3}；
boost:：grid\u图形网格（长度）；
图形；
霉菌复制机；
//使用3-Arg版本的copy_graph，以便我们可以指定自定义的复制方式来创建属性
boost:：copy_graph（网格、图形、boost:：bgl_named_params（copier））；
}

此示例不编译：

g++ -Wextra -Wall -O2 -g -o copytest.o -c copytest.cc
In file included from /usr/include/boost/graph/grid_graph.hpp:24:0,
                 from copytest.cc:2:
/usr/include/boost/iterator/transform_iterator.hpp: In constructor ‘boost::transform_iterator<UnaryFunction, Iterator, Reference, Value>::transform_iterator() [with UnaryFunc = boost::detail::grid_graph_vertex_at<boost::grid_graph<2u> >, Iterator = boost::counting_iterator<unsigned int, boost::use_default, boost::use_default>, Reference = boost::use_default, Value = boost::use_default]’:
/usr/include/boost/graph/copy.hpp:115:55:   instantiated from ‘static void boost::detail::copy_graph_impl<0>::apply(const Graph&, MutableGraph&, CopyVertex, CopyEdge, Orig2CopyVertexIndexMap, IndexMap) [with Graph = boost::grid_graph<2u>, MutableGraph = boost::adjacency_list<boost::vecS, boost::listS, boost::undirectedS, VertexProperties>, CopyVertex = MyCopy, CopyEdge = MyCopy, IndexMap = boost::grid_graph_index_map<boost::grid_graph<2u>, boost::array<unsigned int, 2u>, unsigned int>, Orig2CopyVertexIndexMap = boost::iterator_property_map<__gnu_cxx::__normal_iterator<void**, std::vector<void*, std::allocator<void*> > >, boost::grid_graph_index_map<boost::grid_graph<2u>, boost::array<unsigned int, 2u>, unsigned int>, void*, void*&>]’
/usr/include/boost/graph/copy.hpp:327:5:   instantiated from ‘void boost::copy_graph(const VertexListGraph&, MutableGraph&, const boost::bgl_named_params<P, T, R>&) [with VertexListGraph = boost::grid_graph<2u>, MutableGraph = boost::adjacency_list<boost::vecS, boost::listS, boost::undirectedS, VertexProperties>, P = MyCopy, T = boost::vertex_copy_t, R = boost::bgl_named_params<MyCopy, boost::edge_copy_t>]’
/mnt/home/ajw/code/hpcwales/copytest.cc:31:66:   instantiated from here
/usr/include/boost/iterator/transform_iterator.hpp:100:26: error: no matching function for call to ‘boost::detail::grid_graph_vertex_at<boost::grid_graph<2u> >::grid_graph_vertex_at()’
/usr/include/boost/graph/grid_graph.hpp:104:7: note: candidates are: boost::detail::grid_graph_vertex_at<Graph>::grid_graph_vertex_at(const Graph*) [with Graph = boost::grid_graph<2u>]
/usr/include/boost/graph/grid_graph.hpp:100:33: note:                 boost::detail::grid_graph_vertex_at<boost::grid_graph<2u> >::grid_graph_vertex_at(const boost::detail::grid_graph_vertex_at<boost::grid_graph<2u> >&)

g++-Wextra-Wall-O2-g-o copytest.o-c copytest.cc
在/usr/include/boost/graph/grid_-graph.hpp:24:0中包含的文件中，
从copytest.cc:2：
/usr/include/boost/iterator/transform\u iterator.hpp:在构造函数'boost:：transform\u iterator:：transform\u iterator（）[带UnaryFunc=boost:：detail:：grid\u graph\u vertex\u at，iterator=boost:：counting\u iterator，Reference=boost:：use\u default，Value=boost:：use\u default]：
/usr/include/boost/graph/copy.hpp:115:55:从“静态void boost:：detail:：copy\u graph\u impl:：apply”实例化（const-graph&、MutableGraph&、CopyVertex、CopyEdge、Orig2CopyVertexIndexMap、IndexMap）[with Graph=boost:：grid\u Graph，MutableGraph=boost:：adjacence\u list，CopyVertex=MyCopy，CopyEdge=MyCopy，IndexMap=boost:：grid\u Graph\u index\u map，Orig2CopyVertexIndexMap=boost:：迭代器属性\u map]'
/usr/include/boost/graph/copy.hpp:327:5：从“void boost:：copy_graph（const VertexListGraph&，MutableGraph&，const boost:：bgl_named_params&”）实例化[带VertexListGraph=boost:：grid_graph，MutableGraph=boost:：adjacency_list，P=MyCopy，T=boost:：vertext_copy_，R=boost:：bgl_named___params]”
/mnt/home/ajw/code/hpcwales/copytest.cc:31:66:从此处实例化
/usr/include/boost/iterator/transform\u iterator.hpp:100:26:错误：调用“boost:：detail:：grid\u graph\u vertex\u at:：grid\u graph\u vertex\u at（）”时没有匹配的函数
/usr/include/boost/graph/grid\u-graph.hpp:104:7：注：候选项为：boost:：detail:：grid\u-graph\u-vertex\u-at:：grid\u-graph\u-vertex\u-at（const-graph*）[带graph=boost:：grid\u-graph]
/usr/include/boost/graph/grid\u graph.hpp:100:33：注：boost:：detail:：grid\u graph\u vertex\u at:：grid\u graph\u vertex\u at（const boost:：detail:：grid\u graph\u vertex\u at&）

我对该错误的分析是，它似乎试图默认构造

网格图

内部的一部分，但由于某些我并不十分清楚的原因，它不能默认构造。 （叮当声并没有告诉我任何我在这里看不到的东西）

问题:

这是将可变图初始化为常规网格的正确方法吗？我最初认为这样做比自己编写函数容易得多，但现在我不太确定

为什么

orig\u to\u copy

和/或

vertex\u index

的默认值在这里不合适？我假设这两个是错误的原因。（如果有的话，哪一个是真正导致问题的原因？我无法解释当前错误的根本原因是什么）

解决这个问题的“正确”方法是什么

---

您的思路是正确的，但代码中有两件事情需要更改。第一件是有一种特殊的方法来定义自定义顶点属性。第二件是BGL命名参数有一种不同的语法（更可取，而且可能是唯一正确的语法）

关于第一项，请参阅。基本上，为了定义自定义顶点属性，您需要首先定义一个“标记类型”（一个名称以

\u t

结尾的

结构）：

然后将标记类型包含在定义内部存储的顶点属性的
boost:：property
模板中的某个位置：

typedef boost::property<boost::vertex_index_t, std::size_t,
        boost::property<vertex_position_t, Position> > VertexProperties;

或：


以下是一个完整的程序，用于将网格复制到
Graph
类型的对象，以供参考：

#include <cassert>
#include <cstddef>
#include <cstdlib>
#include <iostream>
#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/copy.hpp>
#include <boost/graph/graphviz.hpp>
#include <boost/graph/grid_graph.hpp>
#include <boost/property_map/property_map.hpp>

struct vertex_position_t {
    typedef boost::vertex_property_tag kind;
};

struct Position {
    std::size_t x, y;

    Position()
        : x(0), y(0)
    {
    }
};

typedef boost::property<boost::vertex_index_t, std::size_t, boost::property<vertex_position_t, Position> > VertexProperties;
typedef boost::adjacency_list<boost::vecS, boost::listS, boost::undirectedS, VertexProperties> Graph;
typedef boost::graph_traits<Graph> GraphTraits;

namespace detail {
typedef boost::grid_graph<2> Grid;
typedef boost::graph_traits<Grid> GridTraits;

struct grid_to_graph_vertex_copier {
    typedef boost::property_map< Grid, boost::vertex_index_t>::type grid_vertex_index_map;
    typedef boost::property_map< ::Graph, boost::vertex_index_t>::type graph_vertex_index_map;
    typedef boost::property_map< ::Graph, ::vertex_position_t>::type graph_vertex_position_map;

    const Grid& grid;
    grid_vertex_index_map grid_vertex_index;
    graph_vertex_index_map graph_vertex_index;
    graph_vertex_position_map graph_vertex_position;

    grid_to_graph_vertex_copier(const Grid& grid_, Graph& graph)
        : grid(grid_), grid_vertex_index(get(boost::vertex_index_t(), grid_)),
        graph_vertex_index(get(boost::vertex_index_t(), graph)),
        graph_vertex_position(get(::vertex_position_t(), graph))
    {
    }

private:
    Position grid_vertex_index_to_position(std::size_t idx) const {
        unsigned num_dims = grid.dimensions();
        assert(grid.dimensions() == 2);

        idx %= grid.length(0) * grid.length(1);

        Position ret;
        ret.x = idx % grid.length(0);
        ret.y = idx / grid.length(0);

        return ret;
    }

public:
    void operator()(GridTraits::vertex_descriptor grid_vertex, ::GraphTraits::vertex_descriptor graph_vertex) const {
        std::size_t idx = get(grid_vertex_index, grid_vertex);
        put(graph_vertex_index, graph_vertex, idx);
        Position pos = grid_vertex_index_to_position(idx);
        std::cout << "grid_vertex = " << idx << ", pos.x = " << pos.x << ", pos.y = " << pos.y << std::endl;
        put(graph_vertex_position, graph_vertex, pos);
    }
};

struct grid_to_graph_edge_copier {
    void operator()(GridTraits::edge_descriptor grid_edge, ::GraphTraits::edge_descriptor graph_edge) const {
    }
};
}

int main()
{
    boost::array<std::size_t, 2> lengths = { { 3, 5 } };
    detail::Grid grid(lengths);

    Graph graph;

    boost::copy_graph(grid, graph, boost::vertex_copy(detail::grid_to_graph_vertex_copier(grid, graph))
            .edge_copy(detail::grid_to_graph_edge_copier()));

    std::cout << std::endl;
    boost::write_graphviz(std::cout, graph);

    return EXIT_SUCCESS;
}

#包括
#包括
#包括
#包括
#包括
#包括
#包括
#包括
#包括
结构顶点位置{
typedef boost:：vertex_属性_标记种类；
};
结构位置{
标准：尺寸x，y；
职位（
：x（0），y（0）
{
}
};
typedef boost:：属性VertexProperties；
类型
boost::named_parameter1(val1).named_param2(val2)

boost::named_parameter2(val2).named_param1(val1)

#include <cassert>
#include <cstddef>
#include <cstdlib>
#include <iostream>
#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/copy.hpp>
#include <boost/graph/graphviz.hpp>
#include <boost/graph/grid_graph.hpp>
#include <boost/property_map/property_map.hpp>

struct vertex_position_t {
    typedef boost::vertex_property_tag kind;
};

struct Position {
    std::size_t x, y;

    Position()
        : x(0), y(0)
    {
    }
};

typedef boost::property<boost::vertex_index_t, std::size_t, boost::property<vertex_position_t, Position> > VertexProperties;
typedef boost::adjacency_list<boost::vecS, boost::listS, boost::undirectedS, VertexProperties> Graph;
typedef boost::graph_traits<Graph> GraphTraits;

namespace detail {
typedef boost::grid_graph<2> Grid;
typedef boost::graph_traits<Grid> GridTraits;

struct grid_to_graph_vertex_copier {
    typedef boost::property_map< Grid, boost::vertex_index_t>::type grid_vertex_index_map;
    typedef boost::property_map< ::Graph, boost::vertex_index_t>::type graph_vertex_index_map;
    typedef boost::property_map< ::Graph, ::vertex_position_t>::type graph_vertex_position_map;

    const Grid& grid;
    grid_vertex_index_map grid_vertex_index;
    graph_vertex_index_map graph_vertex_index;
    graph_vertex_position_map graph_vertex_position;

    grid_to_graph_vertex_copier(const Grid& grid_, Graph& graph)
        : grid(grid_), grid_vertex_index(get(boost::vertex_index_t(), grid_)),
        graph_vertex_index(get(boost::vertex_index_t(), graph)),
        graph_vertex_position(get(::vertex_position_t(), graph))
    {
    }

private:
    Position grid_vertex_index_to_position(std::size_t idx) const {
        unsigned num_dims = grid.dimensions();
        assert(grid.dimensions() == 2);

        idx %= grid.length(0) * grid.length(1);

        Position ret;
        ret.x = idx % grid.length(0);
        ret.y = idx / grid.length(0);

        return ret;
    }

public:
    void operator()(GridTraits::vertex_descriptor grid_vertex, ::GraphTraits::vertex_descriptor graph_vertex) const {
        std::size_t idx = get(grid_vertex_index, grid_vertex);
        put(graph_vertex_index, graph_vertex, idx);
        Position pos = grid_vertex_index_to_position(idx);
        std::cout << "grid_vertex = " << idx << ", pos.x = " << pos.x << ", pos.y = " << pos.y << std::endl;
        put(graph_vertex_position, graph_vertex, pos);
    }
};

struct grid_to_graph_edge_copier {
    void operator()(GridTraits::edge_descriptor grid_edge, ::GraphTraits::edge_descriptor graph_edge) const {
    }
};
}

int main()
{
    boost::array<std::size_t, 2> lengths = { { 3, 5 } };
    detail::Grid grid(lengths);

    Graph graph;

    boost::copy_graph(grid, graph, boost::vertex_copy(detail::grid_to_graph_vertex_copier(grid, graph))
            .edge_copy(detail::grid_to_graph_edge_copier()));

    std::cout << std::endl;
    boost::write_graphviz(std::cout, graph);

    return EXIT_SUCCESS;
}

grid_vertex = 0, pos.x = 0, pos.y = 0
grid_vertex = 1, pos.x = 1, pos.y = 0
grid_vertex = 2, pos.x = 2, pos.y = 0
grid_vertex = 3, pos.x = 0, pos.y = 1
grid_vertex = 4, pos.x = 1, pos.y = 1
grid_vertex = 5, pos.x = 2, pos.y = 1
grid_vertex = 6, pos.x = 0, pos.y = 2
grid_vertex = 7, pos.x = 1, pos.y = 2
grid_vertex = 8, pos.x = 2, pos.y = 2
grid_vertex = 9, pos.x = 0, pos.y = 3
grid_vertex = 10, pos.x = 1, pos.y = 3
grid_vertex = 11, pos.x = 2, pos.y = 3
grid_vertex = 12, pos.x = 0, pos.y = 4
grid_vertex = 13, pos.x = 1, pos.y = 4
grid_vertex = 14, pos.x = 2, pos.y = 4

graph G {
0;
1;
2;
3;
4;
5;
6;
7;
8;
9;
10;
11;
12;
13;
14;
0--1 ;
1--2 ;
3--4 ;
4--5 ;
6--7 ;
7--8 ;
9--10 ;
10--11 ;
12--13 ;
13--14 ;
1--0 ;
2--1 ;
4--3 ;
5--4 ;
7--6 ;
8--7 ;
10--9 ;
11--10 ;
13--12 ;
14--13 ;
0--3 ;
1--4 ;
2--5 ;
3--6 ;
4--7 ;
5--8 ;
6--9 ;
7--10 ;
8--11 ;
9--12 ;
10--13 ;
11--14 ;
3--0 ;
4--1 ;
5--2 ;
6--3 ;
7--4 ;
8--5 ;
9--6 ;
10--7 ;
11--8 ;
12--9 ;
13--10 ;
14--11 ;
}