Boost.Graph is_adjacent

boost::is_adjacent()は、グラフ内において2つの頂点が隣り合っているかを判定する関数です。
この関数はにあります。

namespace boost {
    template <class Graph, class Vertex>
    bool is_adjacent(Graph& g, Vertex a, Vertex b);
}

サンプル：

#include <iostream>
#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/graph_utility.hpp>
#include <boost/assign/list_of.hpp>

#include <boost/detail/lightweight_test.hpp>

typedef boost::adjacency_list<boost::listS, boost::vecS, boost::undirectedS> Graph;
typedef std::pair<int, int> Edge;

enum { A, B, C, D, E, N };
const int vertex_count = N;

int main()
{
    const std::vector<Edge> edges = boost::assign::list_of<Edge>
        (A, B)(B, E)
        (A, C)(C, E)
        (A, D)(D, E)
    ;

    const Graph g(edges.begin(), edges.end(), vertex_count);

    BOOST_TEST(boost::is_adjacent(g, A, B));
    BOOST_TEST(boost::is_adjacent(g, B, E));
    BOOST_TEST(boost::is_adjacent(g, A, C));
    BOOST_TEST(boost::is_adjacent(g, C, E));
    BOOST_TEST(boost::is_adjacent(g, A, D));
    BOOST_TEST(boost::is_adjacent(g, D, E));

    BOOST_TEST(!boost::is_adjacent(g, A, E));

    BOOST_TEST(!boost::is_adjacent(g, B, C));
    BOOST_TEST(!boost::is_adjacent(g, B, D));
    BOOST_TEST(!boost::is_adjacent(g, C, D));

    return boost::report_errors();
}