c++ - Can a derived class be made uncopyable by declaring copy constructor/operator private in base class? -

i thought in theory answer question yes.

however, in practice, compiler (vs2010) not seem complain in following situation: have abstract base class providing common interface (yet having no data members) , various sub , subsubclasses derived it.

class base  { public:     base() {}     virtual ~base() {}      virtual void interfacefunction1() = 0;     virtual void interfacefunction2() = 0; private:     base(const base&);            // derived classes should uncopyable     base& operator=(const base&);      // no data members }; 

my compiler found unproblematic implement full copy constructors in sub- or subsubclasses.

how can make sure every class derived base uncopyable?

edit: if understand well, scott meyers explained in item 6 of effective c++ (3rd edition, 2005) idea of class uncopyable (only extended here full interface class). difference makes idea work ? (i know inherits privately, should not pose problem)

this should prevent compiler generating copy constructor derived classes not declare 1 explicitly. however, nothing prevents derived class explicitly declaring copy constructor else call copy constructor of base.

there no way make sure derived classes instantiable not copyable.