Question

i.e.

class A {
    public:
    A(Apar1, Apar2, Apar3 /* and so on ... */);
};

class B {
public:
    B(Bpar1, Bpar2, Bpar3 /* and so on ... */);
};

class C {
public:
    // C();
private:
    A m_a;
    B m_b;
};

where C construct depends on A and B, so

1. the constructor of C must be the following signature?

   C::C(Apar1, Apar2, Apar3, Bpar1, Bpar2, Bpar3)

2. How can I construct C in a natural way?

Answer 1

You could create a constructor like this instead:

class C {
public:
    C (const A &a, const B &b) : m_a(a), m_b(b) {}
private:
    A m_a;
    B m_b;
};

C c(A(...),
    B(...));

Whether or not you find this more natural or not is a matter of taste,