C++ Programming :: Nested class with public access????


	Nested class with public access???? I have a small question w.r.t nested class.. I see in many codes nested classes are declared as public.. First, of all my understanding is that you go in for a nested class if you are sure that this class cannot exist on it's own.. So , generally this should be declared as private so that none can instantiate this openly.. I need to know the following.. a)Is there any design advantage of having nested class as Public??? class A{ public: class B{ - Hide quoted text - }; B b; } On 21 Maj, 13:34, Nike <pra.ra@gmail.com> wrote: > I have a small question w.r.t nested class.. > I see in many codes nested classes are declared as public.. > First, of all my understanding is that you go in for a nested class if > you are sure that this class cannot exist on it's own.. > So , generally this should be declared as private so that none can > instantiate this openly.. > I need to know the following.. > a)Is there any design advantage of having nested class as Public??? I'd say it's useful to indicate that a class is (as you said) strongly connected with another. Consider for example an implementation of a list: class List { public: struct Node { Node* prev; Node* next; }; private: Node* first; }; However in many cases you might not want to make the implementation public so you would perhaps make it private. Another use (though not for classes) is for enums: class Foo { public: enum Type{ One, Two }; void setType(Type); }; int main() { Foo f; f.setType(Foo::Two); } -- Erik Wikstrm