Mark template specialization as delete

delete_template_specialization.cpp

// item 11: mark function as delete
class Widget {
 public:

  Widget(const Widget&) = delete; // delete copy ctor
  Widget& operator=(const Widget& rhs)= delete; // delete copy=

  template<typename T>
  void process_pointer(T* ptr) {}

};

template<>
void Widget::process_pointer<void>(void*) = delete; // template specialization can be deleted in the namespace scope