无法在C ++的派生类中重载基类方法

我想做什么

我正在将使用dynamic_casting来标识派生类（形状）以应用派生类特定处理的现有代码库转换为基于访问者模式的方案。为此，我在基类（虚拟）中添加了processMe方法，并在每个派生类中添加了ShapeShape类的handleShape方法，每种要处理的形状类型（典型的访客模式）都添加了一个handleShape方法。我有一个ShapeProcessor抽象基类，该基类具有一个纯虚拟方法，该方法强制用户提供所有形状处理器，并允许用户从ShapeProcessor派生并根据需要添加其他形状处理方法（例如MyShapeProcessor：public ShapeProcessor）

观察

但是，发现是在MyShapeProcessor中仅针对所有形状调用了catch all方法，而没有调用我的形状特定方法。我需要做些什么才能获得所需的形状特定方法？警告：如果我将所有处理程序方法放在一个类中，它将很好地工作。这是否意味着不可能在基类中重载方法？我已经阅读了有关隐藏姓名的帖子，但似乎不适用于此处。还是呢？我尝试使用“使用”取消隐藏基类方法，但似乎无济于事。

这是伪代码示例：

class Shape {
    virtual void processMe (ShapeProcessor * sp) {
        sp->processShape (*this);
}

// User derived shape
class Circle : public Shape {
    void processMe (ShapeProcessor * sp) {
        sp->processShape (*this);
}

// Base ShapeProcessor
class ShapeProcessor {
    virtual void processShape (Shape& shape) = 0; // User must provide a catch all method
}

// User provided shape processor
class MyShapeProcessor : public ShapeProcessor {
    void processShape (Circle& circle) {
       // Never gets called, even for Circle objects!
    }
    void processShape (Shape& shape) {
       // Always gets called for all shapes!
       cout << "Unsupported shape!" << endl;
    }
}

// User code
Circle * circle = new Circle();
MyShapeProcessor * sp = new MyShapeProcessor();
circle->processMe (sp);  

// Expecting processMe to eventually call MyShapeProcessor processShape (Circle) but calls processShape (Shape)

// Caveat: If I get rid of the ShapeProcessor base class and if I put all shape handles in a single class
// it works fine. Does this mean that it is not possible to overload methods in the base class? I have read
// the posts on name hiding, but that does not seem to apply here. Or does it?