Re: potential linkage circular dependencies? (maybe slightly OT)

I am working on a suite of existing libraries and I anticipate a
future problem. the problem (as i see it), arises as a result of the
following:
There is a class A that resides in librray A, and class B that resides
in library B.

class B is declared as ff:

class B
{
public:
B();
set_parent(A* a);
B(const B& b);
B& opeartor=(const B& b);
~B();

private:
A * m_parent ;
};

the requirement is that class B can make calls back into the parent,
(when the ptr is non-null)

class A has a method foobar, implemented as ff:

A::foobar()
{
B * b = new B();
//assume no error for sake of brevity
b->set_parent(this);
//do something with b
}

As it stands, my current understanding is that library A will need to
link into library B (and vice versa) - I think this will end in
unresolved references. can any one assure me that my worries are
unfounded?

if I have reason to worry though (for the above reasons), then [..]