Why aren't both modified? What should I do to modify them both?

[wispy sentinel]

Do I need pointers to the objects?

class B
{
    private:
        int x;
    public:
        B() {};
        B(int a)
{x = a;}
        ~B() {}
        int size() {
          return x;
}
        void add() {
   x++;
}
};
class A
{
    private:
        B b;
    public:
        A() {}
        ~A() {}
        A(B b2){
        this->b = b2;
            }
        int size(){
   return b.size();
}
};

int main()
{
    B b(3);
    A a(b);
    b.add();
    cout << b.size() << endl; //4
    cout << a.size() << endl; //3
}

[flat gull]

When your question is answered use !solved to mark the question as resolved.

Remember to ask specific questions, provide necessary details, and reduce your question to its simplest form. For tips on how to ask a good question run !howto ask.

[fair depot]

!f

[flat gull]

Do I need pointers to the objects?

class B {
 private:
  int x;

 public:
  B(){};
  B(int a) { x = a; }
  ~B() {}
  int size() { return x; }
  void add() { x++; }
};
class A {
 private:
  B b;

 public:
  A() {}
  ~A() {}
  A(B b2) { this->b = b2; }
  int size() { return b.size(); }
};

int main() {
  B b(3);
  A a(b);
  b.add();
  cout << b.size() << endl;  // 4
  cout << a.size() << endl;  // 3
}

browngoose2002

Formatted by Zelis, Herald of Krill Issues

[fair depot]

You don't need to define a destructor that does nothing

A(B b2) { this->b = b2; } is taking an instance of B by value and copying it

Take a look at references

[wispy sentinel]

A(B &b2) still does nothing

[fair depot]

Correct

A(B& b2) { this->b = b2; } is still copying whatever b2 refers to

[wispy sentinel]

so... what should I do?

[fair depot]

You need to make data member b in A a reference too

And then you'll need to use a member initializer list to bind the reference

[wispy sentinel]

ohhh DONE! it was a little to modify. Thank you!

[fair depot]

Happy to help

[flat gull]

@wispy sentinel Has your question been resolved? If so, run !solved :)