RhodeCode

  /// general, connected, biconnected, triangle-free, 4-cycle-free,

  /// bipartite and graphs with given edge number and degree

  /// constraints). This function reads a \e nauty \e graph6 \e format

  /// line from the given stream and builds it in the given graph.

  ///

  /// The site of nauty package: http://cs.anu.edu.au/~bdm/nauty/

  ///

  /// For example, the number of all non-isomorphic connected graphs

  /// can be computed with following code.

  ///\code

  /// int num = 0;

  /// SmartGraph graph;

  ///   if (pc.run()) ++num;

  /// }

  /// std::cout << "Number of planar graphs: " << num << std::endl;

  ///\endcode

  ///

  /// The nauty files are quite huge, therefore instead of the direct

  /// file generation the pipelining is recommended.

  ///\code

  /// ./geng -c 10 | ./num_of_pg

  ///\endcode

  template <typename Graph>

    graph.clear();

    std::string line;

    if (getline(is, line)) {

      int index = 0;

      int n;

      if (line[index] == '>') {

        index += 10;

      }