reference counting function objects

From: Greg Colvin (greg_at_[hidden])
Date: 2000-11-26 13:50:18

I'm attempting to provide shared_ptr::operator() by adding lines like

      typename T::result_type operator()() const {
         return (*get())();
      }

but the EDG compiler complains

      "shared_ptr.hpp", line 175: error: name followed by "::" must be a class or
          namespace name
        typename T::result_type operator()() const {
                 ^

when I try to instantiate shared_ptr with a type that has no result_type.

Any suggestions?