CODEWITHSUNDEEP
c++
dchhetri
dchhetri

Reputation: 7136

Call a outter class virtual function from inner class of a static object

Easier to show than explain in only words

class OutterBase{
     protected:
       virtual ItemList buildDefaultItemListForCatagory1();

       class Inner{
           ItemList catagory1, catagory2;
           public: 
               void Inner(){ _initOnce(); }
           private:
               void _initOnce(){ 
                    /* want to be able call the virtual buildDefaultItemListForCatagory1 */
               }
       }

     typedef Singleton<Inner> InnerClassType; //has static getInstance method to get Inner object
}

class OutterDerived: public OutterBase{
   virtual ItemList buildDefaultItemListForCatagory1();
}

So that's the situation right now. I want to be able to call the virtual buildDefaultItemListForCatagory1 inside Inner::_initOnce function. Is there a way to do this.

If not possible, then I need to redesign this. I want to only have one instance of Inner class in OutterBase and have it available to any derived class. I also need it to be constructed depending on the virtual buildDefault* function. Can someone suggest an alternative good solution if the above is not achievable? Thanks.

Upvotes: 0

Views: 141

Answers (2)

user1610015
user1610015

Reputation: 6668

You can.

A nested (inner) class is a member with all the access rights of a normal member and thus has access to the protected and private members of its outer class.

The question is: call it on which object?

Upvotes: 1

gogoprog
gogoprog

Reputation: 613

You can pass the outter object to the inner class constructor and do something like this:

class OutterBase{
     protected:
       virtual ItemList buildDefaultItemListForCatagory1();

       class Inner{
           ItemList catagory1, catagory2;
           OutterBase *outter;
           public: 
               Inner(OutterBase *_outter){ outter=_outter;_initOnce(); }
           private:
               void _initOnce(){ 
                    outter->buildDefaultItemListForCatagory1();
               }
       }

     typedef Singleton<Inner> InnerClassType; //has static getInstance method to get Inner object
}

Upvotes: 0

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