Thread: use reference as class member

Dear friends:
I am confused about the problem of "using reference as class member". For example, i have two classes.

Code:

 class A
{
public:
  A(Mesh& FM):FVmesh(FM){}
private:
  Mesh& FVmesh;
}
  
 class B
{
  B(A& FAA):AA(FAA){}

private:
    A&   AA;
}

The class B use the reference of A as a class member, it will not compiled sucessfully. Since class A must have a "Mesh& FM" to initilize it class member.
one solution is to use pointer as the class member of class B. But how to resolve this problem with referenes.
Regards