Where Are Exception Objects Stored?

 
  class Exception {};
  int main()
  {
    try 
    {
      throw Exception(); // where is the exception stored?
    }
    catch( Exception & ex) // catch by reference
    {}
  }

The handler catches the exception by reference, not by value. Catching exception by reference is recommended because it's more efficient and it avoids slicing when handling a derived exception object. However, a reader who read this recommendation was intrigued: "If the exception object is created on the stack, why doesn