From: ralfixx@gmx.de   
      
   * Richard Damon    
   | The order of inheritance should not matter for conforming code. A   
   | likely issue is code that assumes &Derived == &Base and does invalid   
   | casting on it.   
      
   Ok, solved it.  The reason for the crash was that the base class pointer   
   was not derived directly from the Derived pointer, but there was another   
   void* involved:   
      
       // virtual base functions omitted for brevity   
       class Unrelated {};   
       class Base {};   
       class Derived : public Unrelated, public Base {};   
      
       Base *p1 = &Derived; // ok   
      
       // push into hashtable and retrieve it back via void*   
       hashtable_put("key", &Derived);   
       void *v = hastable_get("key");   
      
       Base *p2 = (Base*) v; // wrong, vtable offset incorrect   
       Base *p3 = (Derived*) v; // ok, vtable offset correct   
      
   The pointer returned by the hashtable_get() needs first to get cast to   
   the original class pushed into the hashtable, otherwise the compiler   
   can't calculate the correct vtable offset (obvious once you grok it).   
      
   So my original observation that p2 and the original pointer were the   
   same was indeed the cause of the problem, they must *not* be the same   
   if Base is not the first base-class of Derived.   
      
   Another lesson learned.  Had I looked up and posted the *real* code in   
   the first place instead of trying to simplify, I'm sure the error would   
   have been obvious (maybe even *before* posting :-)   
      
   Thanks   
   R'   
      
      
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