Re: questions about dynamic binding

On May 12, 12:13 pm, Jess <w...@hotmail.com> wrote:

The classical solution here is to provide a clone function in
the base class, i.e.:

    class A
    {
    public:
        A* clone() const
        {
            A* result = doClone() ;
            assert( typeid( *result ) == typeid( *this ) ) ;
            return result ;
        }

    private:
        virtual A* doClone() const
            // Except that usually, this will be pure virtual.
            // It's fairly rare to have virtual functions in a
            // base class which aren't pure virtual.
        {
            return new A( *this ) ;
        }
    } ;

    class B
    {
    private:
        virtual A* doClone() const
        {
            return new B( *this ) ;
        }