Multiple Inheritance, copy constructor, and base class initialization?

Question

How do I write a copy constructor with Multiple Inheritance?

B1 and B2 is inherited by D there is no diamond in inheritance chain. I need to write a copy constructor in D such that it calls copy constructors of B1 and B2

I want to avoid writing a clone() here

Answer 1

What's wrong with the classical approach:

D(const D& other) : B1(other), B2(other)
{
}

?