Boost C++ Libraries

...one of the most highly regarded and expertly designed C++ library projects in the world. Herb Sutter and Andrei Alexandrescu, C++ Coding Standards

Click here to view the latest version of this page.
C++ Boost

edge_list<EdgeIterator, ValueType, DiffType>

The edge_list class is an adaptor that turns a pair of edge iterators into a class that models EdgeListGraph. The value_type of the edge iterator must be a std::pair (or at least have first and second members). The first_type and second_type of the pair must be the same and they will be used for the graph's vertex_descriptor. The ValueType and DiffType template parameters are only needed if your compiler does not support partial specialization. Otherwise they default to the correct types.

Example

Applying the Bellman-Ford shortest paths algorithm to an edge_list.

  enum { u, v, x, y, z, N };
  char name[] = { 'u', 'v', 'x', 'y', 'z' };

  typedef std::pair<int,int> E;
  E edges[] = { E(u,y), E(u,x), E(u,v),
                E(v,u),
                E(x,y), E(x,v),
                E(y,v), E(y,z),
                E(z,u), E(z,x) };
  
  int weight[] = { -4, 8, 5,
                   -2,
                   9, -3,
                   7, 2,
                   6, 7 };

  typedef boost::edge_list<E*> Graph;
  Graph g(edges, edges + sizeof(edges) / sizeof(E));
    
  std::vector<int> distance(N, std::numeric_limits<short>::max());
  std::vector<int> parent(N,-1);
  
  distance[z] = 0;
  parent[z] = z;
  bool r = boost::bellman_ford_shortest_paths(g, int(N), weight,
                                              distance.begin(),
                                              parent.begin());
  if (r)  
    for (int i = 0; i < N; ++i)
      std::cout << name[i] << ": " << distance[i]
                << " " << name[parent[i]] << std::endl;
  else
    std::cout << "negative cycle" << std::endl;
The output is the distance from the root and the parent of each vertex in the shortest paths tree.
  u: 2 v
  v: 4 x
  x: 7 z
  y: -2 u
  z: 0 z

Where Defined

boost/graph/edge_list.hpp

Template Parameters

ParameterDescription
EdgeIterator Must be model of InputIterator who's value_type must be a pair of vertex descriptors.
ValueType The value_type of the EdgeIterator.
Default: std::iterator_traits<EdgeIterator>::value_type
DiffType The difference_type of the EdgeIterator.
Default: std::iterator_traits<EdgeIterator>::difference_type

Model of

EdgeListGraph

Associated Types


boost::graph_traits<edge_list>::vertex_descriptor

The type for the vertex descriptors associated with the edge_list. This will be the same type as std::iterator_traits<EdgeIterator>::value_type::first_type.
boost::graph_traits<edge_list>::edge_descriptor

The type for the edge descriptors associated with the edge_list.
boost::graph_traits<edge_list>::edge_iterator

The type for the iterators returned by edges(). The iterator category of the edge_iterator will be the same as that of the EdgeIterator.

Member Functions


edge_list(EdgeIterator first, EdgeIterator last)

Creates a graph object with n vertices and with the edges specified in the edge list given by the range [first,last).

Non-Member Functions


std::pair<edge_iterator, edge_iterator>
edges(const edge_list& g)


Returns an iterator-range providing access to the edge set of graph g.
vertex_descriptor
source(edge_descriptor e, const edge_list& g)


Returns the source vertex of edge e.
vertex_descriptor
target(edge_descriptor e, const edge_list& g)


Returns the target vertex of edge e.


Copyright © 2000-2001 Jeremy Siek, Indiana University (jsiek@osl.iu.edu)
Lie-Quan Lee, Indiana University (llee@cs.indiana.edu)
Andrew Lumsdaine, Indiana University (lums@osl.iu.edu)