Is it possible to clone a polymorphic object without manually adding overridden clone method into each derived class in C++?

Question

The typical pattern when you want to copy a polymorphic class is adding a virtual clone method and implement it in each derived class like this:

Base* Derive         


        

Answer 1

You can at minimum avoid writing the class name by getting it from the type of the class itself with:

struct A: public Base
{
    Base* Clone() { return new std::remove_reference_t(*this); }
};

Using CRTP will not help avoid duplicating the class name again, as you than have to write the class name inside the template parms for the CRTP base.