We shouldn't allow these because the default versions will copy
the reference count which is definitely not what we want.
int count;
private:
+ // Don't allow a default copy constructor or copy operator on
+ // these objects because the default operation will copy the
+ // reference count as well and we certainly don't want that.
RefCounted(const RefCounted &);
+ RefCounted &operator=(const RefCounted &);
public:
RefCounted() : count(0) {}