Template w/derived func return type equivalence bug

I've distilled an issue that I'm having down to the following code snippet,
which I believe should compile, but instead clang is flagging "not covariant" return types...

#include<stdexcept>

class base : public std::exception
{
public:
  virtual base * move() throw () = 0;
};

template <typename T>
class derived : public base
{
public:
         derived *move() throw() {return 0;}
};

Definitely a bug. Could you file a Bugzilla at http://llvm.org/bugs/ so we don't lose track of this bug?

  - Doug