inheritance - Should I inherit a nested class within a derived class in c++? -

could (edit: should) this?

edit:

i'll try asking example may better suited inheritence scheme. note isn't working class, concept.

template<typename t> class tree { protected:     class node {        node* _parent;        t _data     }; };  template<typename t> class binarytree: public tree { private:     class binarynode: public tree<t>::node {         node *_left, *_right;     }; }; 

this way of constructing parallel class hierarchies not uncommon. however, more common hide nested derived class implementation detail should encapsulated, i.e. biiterator in example in private: section.

however, iterator not example because of object slicing: if biiterator remains public, seemingly innocent code incorrect:

bidirectionallist bilist; // slice off biiterator's functionality iterator iter(bilist.get_iterator()); while (iter.has_next()) {     ... } 

a better example if base class member function took reference or pointer object of nested class defined in base, , derived class pass derived nested class it:

class task { public:     class worker {         public virtual void work()=0;     }     void run(worker& w); }; class specialtask : public task { private:     class specialworker : public worker {         public virtual void work() {             ...         }     }; public:     void do_something() {         specialworker w;         run(w); // passes specialworker run() of base class     } };