🚀 go-pugleaf

I have got error message from the compiler for:
--------------------------------------------------------------------------
class A { };

template <class T> 
class xyz  : virtual public A
{
public:
           xyz();
           xyz<T>(const xyz<T>& s);
           xyz<T>& operator=(const xyz<T>& c);
};

template <class T>
xyz<T>& xyz<T>::operator=(const xyz<T> &s)
  { }

template <class T>
xyz<T>::xyz(const xyz<T> &s)
  { }

main() { xyz<int> ixyz; }
--------------------------------------------------------------------------
g++ v2.5.3 compiled for sun-4 says:

test13rep.cc: In function `int main()':
test13rep.cc:10: inconsistent return types for method `xyz' in class `xyz<int>'

If I erase 'virtual' then it's OK. If I don't use template then it's OK.
Any ideas? Why this might be?

Thank you,
Vassili Leonov.