Dirk Gregorius wrote:
Does inheriting from boost::noncopyable has the same effect like making the copy c'tor and the assignment operator private without implementing them? The authors of the smart_ptr library suggest the following for the use of the smart pointers with interfaces:
class Interface { public: virtual void f() = 0; virtual void g() = 0;
protected: ~Interface( void ) {}; // non-virtual }
// #1 class Implementation : public Interface { public: void f() { /* Implementation */ } void g() { /* Implementation */ }
private: // Not to be implemented Implementation( const Implementation& ); Implementation& operator=( const Implementation& ); };
Does it really make any sense making only implementation noncopyable, rather than interface? If you deal with interfaces only it won't save you from errors like this: std::auto_ptr<Interface> create() { return std::auto_ptr<Interface>(new Implementation); } void foo() { std::auto_ptr<Interface> a(create()), b(create()); *a = *b; // oops, no error here, Implementation::operator= is not considered } -- Maxim Yegorushkin