c++ private constructors

Question

If I don't want to allow anyone to create an instance of my class except for my static functions (I think this is called singleton/factory?), is it enough to make the default constructor private, or do I also need to explicitly define and make private a copy constructor and assignment operator?

Answer 1

Making the constuctor private is for the factory method pattern. The singleton pattern needs a factory method.
boost has noncopyable if you don't want your class to be copied, but as James McNellis already commented: decide whether users should be able to copy the class. Because raw pointers and the inherent memory management should not have a place in classes anymore, the question of having classes copied is mostly for classes that use resources or possibly large containers.