Boost/BGL/EdgeExists

EdgeExists.cpp

#include <iostream>
#include <boost/graph/adjacency_list.hpp>
 
typedef boost::adjacency_list<boost::vecS, boost::vecS, boost::undirectedS> Graph;
 
int main(int,char*[])
{
  // Create a graph object
  Graph g;
  Graph::vertex_descriptor v0 = boost::add_vertex(g);
  Graph::vertex_descriptor v1 = boost::add_vertex(g);
 
  // Check if an edge between v0 and v1 exists. It should not at this point.
  std::cout << "Edge exists?" << boost::edge(v0, v1, g).second << std::endl; // false
 
  // Add an edge between v0 and v1.
  std::pair<Graph::edge_descriptor, bool> e0 = boost::add_edge(v0, v1, g);
 
  // Check again if an edge between v0 and v1 exists. It should now.
  std::cout << "Edge exists?" << boost::edge(v0, v1, g).second << std::endl; // true
 
  // A demonstration of the full return type of edge(). At this point, retrievedEdge.first
  // should be exactly equal to e0
  std::pair<Graph::edge_descriptor, bool> retrievedEdge = boost::edge(v0, v1, g);
 
  return 0;
}

CMakeLists.txt

cmake_minimum_required(VERSION 2.6)
 
Project(EdgeExists)
 
set(Boost_USE_MULTITHREADED ON)
FIND_PACKAGE(Boost 1.38 COMPONENTS required)
 
INCLUDE_DIRECTORIES(${INCLUDE_DIRECTORIES} ${Boost_INCLUDE_DIRS})
LINK_DIRECTORIES(${LINK_DIRECTORIES} ${Boost_LIBRARY_DIRS})
 
ADD_EXECUTABLE(EdgeExists EdgeExists.cpp)