// Clonable and nested Base, including their inline members:
    class Clonable
    {
        public:
            class Base;
        private:
            Base *d_bp;
        public:
            class Base
            {
                public:
                    virtual ~Base();
                    Base *clone() const;
                private:
                    virtual Base *newCopy() const = 0;
            };
            Clonable();
            explicit Clonable(Base *base);
            ~Clonable();
            Clonable(Clonable const &other);
            Clonable(Clonable &&tmp);
            Clonable &operator=(Clonable const &other);
            Clonable &operator=(Clonable &&tmp);

            Base &base() const;
    };
    inline Clonable::Base *Clonable::Base::clone() const
    {
        return newCopy();
    }
    inline Clonable::Base &Clonable::base() const
    {
        return *d_bp;
    }

// Derived and its inline member:
    class Derived1: public Clonable::Base
    {
        public:
            ~Derived1();
        private:
            virtual Clonable::Base *newCopy() const;
    };
    inline Clonable::Base *Derived1::newCopy() const
    {
        return new Derived1(*this);
    }

// Members not implemented inline:
    Clonable::Base::~Base()
    {}