How can I expand call to variadic template base classes?

I have a set of non-orthogonal policies, all of them implementing a common named method, the policies add safety checks. I want users to be able to combine the policies to allow more complex validation without creating policies for each combination case by hand. My approach is creating a new policy class to combine others.

The simplified example below shows C as the combining class, here the method id is combined. The expected result is, when calling id on C, to sequentially call the id of each base class.

#include <iostream>
using namespace std;

struct A {
    void id() { cout << "A ";}
};

struct B {
    void id() { cout << "B ";}
};

template<class A, class... As>
struct C : public A, public As... {
    void id(){
    A::id();
    As...::id(); // This line does not work, it is illustrative.
}
};

int main(){
    C<A, B> c;
    c.id();
    //expected: result A B 
}

The question is: Is it possible to expand As... somehow to do this without using a recursive approach, just using the ... operator?