Question

Here’s my problem:

I have 1 class that creates two new instances of a two other classes, and now I would need to either have a direct availability from one of the instances to the other, is this possible and if so, how?

so:

in Class A:

b = new B(5); // where 5 is an int data member of B
c = new C();

and let B::bee() be a function I would need to access from C() BUT, I would need to access members of B (not a new instance of B) created by A.

So C::getIntfromB(){
  b->getInt();
}

Or something.

I’ve tried going for:

b = new B(5);
c = new C(*b);

having a B b; private member for C

However for some reason I simply cannot get it to work properly, what is the obvious error I am making?

Answer 1

Your C member should be a pointer or a reference (B *b or B &b). If it’s a B it will copy your B object, so it will refer to a different instance (which has been created by copying the one you’re interested into).

Also, you’ll need to pass your b object as a pointer or a reference, otherwise a new instance will be created while passing the parameter, and your pointer/reference in C class will refer to that one. (This would also lead to other problems, since such copy would be a temporary getting destroyed as soon as C‘s constructor returns)