C++“纯虚方法调用”,使用抽象基类[复制]

就我的研究而言,这似乎是一条路要走。

我必须抽象基类、GraphReader和Graph。

class Graph{
   public:
   Graph() {};
   virtual ~Graph() {};
   virtual void layout() = 0;
   virtual std::vector<std::shared_ptr<Node>> getNodes() = 0;
   virtual std::vector<std::shared_ptr<Edge>> getEdges() = 0;

   protected:

};

class GraphReader{
   public:
   GraphReader(std::string fileName_) :
         fileName(fileName_) {};
   virtual ~GraphReader() {};
   virtual Graph* read() = 0;

   protected:
   std::string fileName;
};

class OgdfGraph : public Graph{
   public:
   OgdfGraph();
   virtual ~OgdfGraph();
   void setOgdfGraph(ogdf::Graph &oGraph);
   std::vector<std::shared_ptr<Node>> getNodes();
   std::vector<std::shared_ptr<Edge>> getEdges();
   void layout();

   private:
   [...]

};

class OgdfGmlReader : public GraphReader {  
   public:
   OgdfGmlReader(std::string fileName);
   virtual ~OgdfGmlReader();
   Graph* read();    
};

Graph* OgdfGmlReader::read() {

   [...]

   OgdfGraph og;
   og.setOgdfGraph(G);
   Graph* graph = &og;

   return graph;
}

我主要做以下几点:

   OgdfGmlReader tr = OgdfGmlReader("../data/lesmiserables.gml");
   GraphReader* gr = &tr;
   Graph* graph = gr->read();

   graph->layout();

图形的加载工作正常,但当我在图形上调用layout函数时,会出现以下错误(在运行时,它会编译):

pure virtual method called
terminate called without an active exception
Aborted (core dumped)

我最困惑的是,它适用于GraphReader,但不适用于Graph(从GraphReader返回),因为这与我的理解完全相同。

非常感谢您对如何解决这个问题(同时可能维护继承架构)的任何帮助!