struct A { explicit A(int u) { _u._u3 = u; } A(const A &) = default; virtual ~A() = default; private: union U { char _u1; short _u2; int _u3; }; A::U _u; }; #pragma pack(push, 1) template struct B : public virtual A { B(char a, unsigned short b, int c) : A(a + b + c), _a(a), _b(b), _c(c) {} private: char _a; unsigned short : 3; unsigned short _b : 6; unsigned short : 4; int _c; }; #pragma pack(pop) #pragma pack(push, 16) class C : private virtual B<0>, public virtual B<1>, private B<2>, public B<3> { public: C(char x, char y, char z) : A(x - y + z), B<0>(x, y, z), B<1>(x * 2, y * 2, z * 2), B<2>(x * 3, y * 3, z * 3), B<3>(x * 4, y * 4, z * 4), _x(x * 5), _y(y * 5), _z(z * 5) {} static int abc; private: int _x; short _y; char _z; }; int C::abc = 123; #pragma pack(pop) class List { public: List() = default; List(List *p, List *n, C v) : Prev(p), Next(n), Value(v) {} private: List *Prev = nullptr; List *Next = nullptr; C Value{1, 2, 3}; }; int main() { List ls[16]; return 0; }