source: downloads/boost_1_34_1/libs/graph/example/edge-function.cpp @ 29

//=======================================================================
// Copyright 2001 Jeremy G. Siek, Andrew Lumsdaine, Lie-Quan Lee, 
//
// Distributed under the Boost Software License, Version 1.0. (See
// accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
//=======================================================================
#include <boost/config.hpp>
#include <iostream>
#include <fstream>
#include <string>
#include <boost/graph/adjacency_list.hpp>

using namespace boost;

template < typename Graph, typename VertexNamePropertyMap > void
read_graph_file(std::istream & graph_in, std::istream & name_in,
                Graph & g, VertexNamePropertyMap name_map)
{
  typedef typename graph_traits < Graph >::vertices_size_type size_type;
  size_type n_vertices;
  typename graph_traits < Graph >::vertex_descriptor u;
  typename property_traits < VertexNamePropertyMap >::value_type name;

  graph_in >> n_vertices;       // read in number of vertices
  for (size_type i = 0; i < n_vertices; ++i) {  // Add n vertices to the graph
    u = add_vertex(g);
    name_in >> name;
    put(name_map, u, name);     // ** Attach name property to vertex u **
  }
  size_type src, targ;
  while (graph_in >> src)       // Read in edges
    if (graph_in >> targ)
      add_edge(src, targ, g);   // add an edge to the graph
    else
      break;
}

template < typename Graph, typename VertexNameMap > void
output_adjacent_vertices(std::ostream & out,
                         typename graph_traits < Graph >::vertex_descriptor u,
                         const Graph & g, VertexNameMap name_map)
{
  typename graph_traits < Graph >::adjacency_iterator vi, vi_end;
  out << get(name_map, u) << " -> { ";
  for (tie(vi, vi_end) = adjacent_vertices(u, g); vi != vi_end; ++vi)
    out << get(name_map, *vi) << " ";
  out << "}" << std::endl;
}

template < typename NameMap > class name_equals_t {
public:
  name_equals_t(const std::string & n, NameMap map)
  : m_name(n), m_name_map(map)
  {
  }
  template < typename Vertex > bool operator()(Vertex u) const
  {
    return get(m_name_map, u) == m_name;
  }
private:
    std::string m_name;
  NameMap m_name_map;
};

// object generator function
template < typename NameMap >
  inline name_equals_t < NameMap >
name_equals(const std::string & str, NameMap name)
{
  return name_equals_t < NameMap > (str, name);
}


int
main()
{
  typedef adjacency_list<listS,// Store out-edges of each vertex in a std::list
    vecS,                      // Store vertex set in a std::vector
    directedS,                 // The graph is directed
    property < vertex_name_t, std::string >     // Add a vertex property
   >graph_type;

  graph_type g;                 // use default constructor to create empty graph
  const char* dep_file_name = "makefile-dependencies.dat";
  const char* target_file_name = "makefile-target-names.dat";

  std::ifstream file_in(dep_file_name), name_in(target_file_name);
  if (!file_in) {
    std::cerr << "** Error: could not open file " << dep_file_name
      << std::endl;
    return -1;
  }
  if (!name_in) {
    std::cerr << "** Error: could not open file " << target_file_name
      << std::endl;
    return -1;
  }

  // Obtain internal property map from the graph
  property_map < graph_type, vertex_name_t >::type name_map =
    get(vertex_name, g);
  read_graph_file(file_in, name_in, g, name_map);

  graph_traits < graph_type >::vertex_descriptor yow, zag, bar;
  // Get vertex name property map from the graph
  typedef property_map < graph_type, vertex_name_t >::type name_map_t;
  name_map_t name = get(vertex_name, g);
  // Get iterators for the vertex set
  graph_traits < graph_type >::vertex_iterator i, end;
  tie(i, end) = vertices(g);
  // Find yow.h
  name_equals_t < name_map_t > predicate1("yow.h", name);
  yow = *std::find_if(i, end, predicate1);
  // Find zag.o
  name_equals_t < name_map_t > predicate2("zag.o", name);
  zag = *std::find_if(i, end, predicate2);
  // Find bar.o
  name_equals_t < name_map_t > predicate3("bar.o", name);
  bar = *std::find_if(i, end, predicate3);

  graph_traits < graph_type >::edge_descriptor e1, e2;
  bool exists;

  // Get the edge connecting yow.h to zag.o
  tie(e1, exists) = edge(yow, zag, g);
  assert(exists == true);
  assert(source(e1, g) == yow);
  assert(target(e1, g) == zag);

  // Discover that there is no edge connecting zag.o to bar.o
  tie(e2, exists) = edge(zag, bar, g);
  assert(exists == false);

  assert(num_vertices(g) == 15);
  assert(num_edges(g) == 19);

  return EXIT_SUCCESS;
}