The library interface implies that the Element object is copied internally into the Atom like the
string fields since the set method takes a const reference and the get method returns a const ref.
However, acting on this implication is pretty catastrophic :-(
Suggestions:
- make Atom::getElement() and PTE::getElement() return pointers
- make Element noncopyable since the instances are just supposed to sit in their table
As a general point, having objects take other objects by reference and then storing a pointer to the
passed object violates most C++ conventions and invites all sorts of problems if, as in this case,
the user gets confused. If the attribute is a pointer to an external object, setting it should take
a pointer. If the attribute is an object the set function should take an object.
The fact that the field is documented as a pointer doesn't really solve the problem since one
doesn't know if that is simply to avoid the memory allocation if the Element is not set.