C/C++ :: How To Use The List Container To Hold A Class

How would I use the list container to hold a class?

class A {
    private : int x;
    public  : void setX(int val) { x = val; }
};  

class B {
    private : std::list<A> pdata;
    public  : void addToList();
};  

For adding, I thought of trying something like

void B::addToList() {
   A *tmp = new A;  
   if(A != 0) {
      tmp->setX(5);
      pdata.insert(tmp);
      delete tmp;
   }
}

How would I do what I'm trying to do? Or is this the wrong way to go about it? For the actual program, "B" would contain several lists of various classes.