title: Is it possible to forbid deriving from a class at compile time?
body: <p>I have a value class according to the description in "C++ Coding Standards", Item 32. In short, that means it provides value semantics and does not have any virtual methods.</p>
  
  <p>I don't want a class to derive from this class. Beside others, one reason is that it has a public nonvirtual destructor. But a base class should have a destructor that is public and virtual or protected and nonvirtual.</p>
  
  <p>I don't know a possibility to write the value class, such that it is not possible to derive from it. I want to forbid it at compile time. Is there perhaps any known idiom to do that? If not, perhaps there are some new possibilities in the upcoming C++0x? Or are there good reasons that there is no such possibility?</p>