define a struct inside a class in C++

Question

Can someone give me a example about how to define a new type of struct in a class in C++.Thanks.

Answer 1

Something like this:

class Class {
    // visibility will default to private unless you specify it
    struct Struct {
        //specify members here;
    };
};

Answer 2

Something like:

class Tree {

 stuct node {
   int data;
   node *llink;
   node *rlink;
 };

 .....
 .....
};

Answer 3

// declare class & nested struct
class C {
    // struct will be private without `public:` keyword
    struct S {
        int sa;
        void func();
    };
    void func();
};

// if you want to separate the implementation (definition)
void C::func() {
    // implementaiton here
}
void C::S::func() {
    // implementation here
}

// if you want to inline the implementation, other answers will do fine.