Derived curiously recurring templates and covariance

Question

Suppose I have a base class which cloning of derived classes:

class Base
{
    public:
        virtual Base * clone()
        {
            return new Base()         


        

Answer 1

A not-so-pretty workaround.

class Base
{
    protected:
        virtual Base * clone_p()
        {
            return new Base();
        }
};


template 
class CRTP : public Base
{
    protected:
        virtual CRTP* clone_p()
        {
            return new T;
        }
    public:
        T* clone()
        {
            CRTP* res = clone_p();
            return static_cast(res);
        }
};


class Derived : public CRTP
{
    public:
};

Use dynamic_cast<> instead of static if you feel it's safer.