ceph/src/boost/libs/graph/example/default-constructor2.cpp

   1 //=======================================================================
   2 // Copyright 2001 Jeremy G. Siek, Andrew Lumsdaine, Lie-Quan Lee,
   3 //
   4 // Distributed under the Boost Software License, Version 1.0. (See
   5 // accompanying file LICENSE_1_0.txt or copy at
   6 // http://www.boost.org/LICENSE_1_0.txt)
   7 //=======================================================================
   8 #include <boost/config.hpp>
   9 #include <fstream>
  10 #include <boost/graph/adjacency_list.hpp>
  11
  12 using namespace boost;
  13
  14 template < typename Graph > void
  15 read_graph_file(std::istream & in, Graph & g)
  16 {
  17   typedef typename graph_traits < Graph >::vertex_descriptor Vertex;
  18   typedef typename graph_traits < Graph >::vertices_size_type size_type;
  19   size_type n_vertices;
  20   in >> n_vertices;             // read in number of vertices
  21   std::vector < Vertex > vertex_set(n_vertices);
  22   for (size_type i = 0; i < n_vertices; ++i)
  23     vertex_set[i] = add_vertex(g);
  24
  25   size_type u, v;
  26   while (in >> u)
  27     if (in >> v)
  28       add_edge(vertex_set[u], vertex_set[v], g);
  29     else
  30       break;
  31 }
  32
  33
  34 int
  35 main()
  36 {
  37   typedef adjacency_list < listS,       // Store out-edges of each vertex in a std::list
  38     vecS,                       // Store vertex set in a std::vector
  39     directedS                   // The graph is directed
  40   > graph_type;
  41
  42   graph_type g;                 // use default constructor to create empty graph
  43   std::ifstream file_in("makefile-dependencies.dat");
  44   read_graph_file(file_in, g);
  45
  46   assert(num_vertices(g) == 15);
  47   assert(num_edges(g) == 19);
  48   return 0;
  49 }