C++接口繼承

Question

我該如何在C++中進行這種派生？ （目前的例子不起作用）

struct IB 
    { 

    }; 

    struct IDerivedB : public IB 
    { 

    }; 

    struct IA 
    { 
    public: 
     virtual IB Foo(const string& type) = 0; 
    }; 

    struct IDerivedA : public IA 
    { 
    public: 
     virtual IDerivedB Foo(const string& type) override = 0; 
    }; 

謝謝！

Answer 1

返回類型的協方差僅適用於指針和引用，這應該工作：

struct IB 
{ 

}; 

struct IDerivedB : public IB 
{ 

}; 

struct IA 
{ 
public: 
    virtual IB* BuildPresenter(const string& type) = 0; 
}; 

struct IDerivedA : public IA 
{ 
public: 
    virtual IDerivedB* BuildPresenter(const string& type) override = 0; 
};