class TFoo : public TSuperFoo { 
    TBar* fBar1; //TBar is monomorphic (1)
     TBar* fBar2;
    // various method definitions go here...
}

//Do not need to be a virtual function 
TFoo& const  //considering: a=b=c and (a=b)=c
TFoo::operator=(const TFoo& that) 
{
//step 1
    if (this == &that) //compare address of this and that
       retur *this;

//step 2
    TBar* bar1 = 0;  //make memory allocation a transaction
    TBar* bar2 = 0;
    try {
         bar1 = new TBar(*that.fBar1);//make a copy, see  (1)
         bar2 = new TBar(*that.fBar2);
         TSuperFoo::operator=(that); //copy super's members 
    }
    catch (...) {
         delete bar1;
         delete bar2;
         throw;
    }

//step 3
    delete fBar1; //free fBar1 
    fBar1 = bar1; //call TBar.=()
    delete fBar2;
    fBar2 = bar2;

//step 4
    return *this;
} 

- posted by Pop @ 11:38 AM