OOP344 Multiple inheritance, casting and temporary nameless objects

Please note the following conversation when dealing with casting in C++:

svn://zenit.senecac.on.ca/oop344/trunk/A/05-Aug05/minh4.cpp

<Neg206> Hello Fardad
<fardad> Neg206: Hi Neg206 
<Neg206> On friday on lecture August 5
<Neg206> minh4.cpp after we set to B to 1234
? fardad is checking out the note
<Neg206> when we print the A(C(d)) is should print to 123456 or -123
<fardad> so, on first look, it you would say that it should print 123456,.....
<fardad> (Line 71 :  A(B(d)).set(123456);)
<fardad> but it won't, 
<fardad> it will print -123
<Neg206> yes why?
<fardad> because A(whatever) is not a call to a constructor(a constructor is not a function and can not be called), but it is creating a temp nameless object
<fardad> so you are setting data to 123456, but 
<fardad> you are setting data of a nameless object who is going to die right at the end of line 71
<fardad> and the original A part of d object remains the same
<Neg206> yes die after simicolon so data is still -123
<fardad> yes, but if you replace line 71 with
<fardad>  d.B::A::set(123456);
<fardad> then you are NOT setting a temp nameless but "A part of object d"
<Neg206> yes thank you

#include <iostream>
using namespace std;



class A{
private:
  int data;
public: 
  A(int data=-123){
    this->data = data;
  }
  void set(int data){
    this->data = data;
  }
  int print(){
    cout<<"A: "<<data<<endl;
    return data;
  }
};

class B: virtual public A{
private:
  int data;
public: 
  B(int data = -2):A(data*4){
    this->data = data;
  }
  int print(){
    A::print();
    cout<<"B: "<<data<<endl;
    return data;
  }
};

class C:virtual public A{
private:
  int data;
public: 
  C(int data = -3):A(data*3){
    this->data = data;
  }
  int print(){
    A::print();
    cout<<"C: "<<data<<endl;
    return data;
  }
};

class D: public B, public C{
private:
  int data;
public: 
  D(int data):B(10),C(20){
    this->data = data;
  }
  int print(){
    B::print();
    C::print();
    cout<<"D: "<<data<<endl;
    return data;
  }
};


int main(void){
  D
    d(100);
  d.print();
 A(d).print();
 //A(B(d)).set(123456);   this will not set the data of "A part of d" please read the comments below...
 d.B::A::set(123456);
 A(C(d)).print();
 return 0;
}