RhodeCode

      // Invalid arc constructor

    /// First node of the edge

    Node u(const Edge &e) const {

      return Parent::source(e);

    }

    /// Source of the given arc

    /// Second node of the edge

    Node v(const Edge &e) const {

      return Parent::target(e);

    }

    /// Target of the given arc

    /// Returns a directed arc corresponding to the specified edge.

    /// If the given bool is true, the first node of the given edge and

    /// the source node of the returned arc are the same.

    static Arc direct(const Edge &e, bool d) {

      return Arc(e, d);

    /// Returns whether the given directed arc has the same orientation

    /// as the corresponding edge.

    static bool direction(const Arc &a) { return a.forward; }