adding custom vertices to a boost graph
If I have n elements defined with class CElement, how can one create vertices of those elements with boost graph - and connect them also? I've seen boost graph bundled props, but I just can't figure 开发者_运维问答this one out.
I don't understand what you want to do exactly. Do you want to associate some data to vertices? Then use bundled properties.
//Define a class that has the data you want to associate to every vertex and edge
struct Vertex{ int foo;}
struct Edge{std::string blah;}
//Define the graph using those classes
typedef boost::adjacency_list<boost::listS, boost::vecS, boost::directedS, Vertex, Edge > Graph;
//Some typedefs for simplicity
typedef boost::graph_traits<Graph>::vertex_descriptor vertex_t;
typedef boost::graph_traits<Graph>::edge_descriptor edge_t;
//Instanciate a graph
Graph g;
// Create two vertices in that graph
vertex_t u = boost::add_vertex(g);
vertex_t v = boost::add_vertex(g);
// Create an edge conecting those two vertices
edge_t e; bool b;
boost::tie(e,b) = boost::add_edge(u,v,g);
// Set the properties of a vertex and the edge
g[u].foo = 42;
g[e].blah = "Hello world";
The are other ways to set the properties, but there you a have an example to bootstrap.
I hope I didn't misunderstand the question.
Note that Boost.Graph has overloads which allow to simplify Tristram's answer:
#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/graphviz.hpp>
#include <iostream>
int main()
{
struct Vertex { int foo; };
struct Edge { std::string blah; };
using namespace boost;
using graph_t = adjacency_list<listS, vecS, directedS, Vertex, Edge >;
using vertex_t = graph_traits<graph_t>::vertex_descriptor;
using edge_t = graph_traits<graph_t>::edge_descriptor;
//Instantiate a graph
graph_t g;
// Create two vertices in that graph
vertex_t u = boost::add_vertex(Vertex{123}, g);
vertex_t v = boost::add_vertex(Vertex{456}, g);
// Create an edge conecting those two vertices
boost::add_edge(u, v, Edge{"Hello"}, g);
boost::write_graphviz(std::cout, g, [&] (auto& out, auto v) {
out << "[label=\"" << g[v].foo << "\"]";
},
[&] (auto& out, auto e) {
out << "[label=\"" << g[e].blah << "\"]";
});
std::cout << std::flush;
}
Output:
digraph G {
0[label="123"];
1[label="456"];
0->1 [label="Hello"];
}
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