template<typename T1, typename T2, typename T3, typename T4, int S>
struct message;
struct Size;
struct of;
struct is;
#define PRINT_SIZE(x) message<Size, of, x, is, sizeof(x)> _##x

struct A {
    unsigned char field_0;
};

struct B {
    unsigned short field_0;
};

struct C {
    unsigned int field_0;
    unsigned char field_4;
};

PRINT_SIZE(A);
PRINT_SIZE(B);
PRINT_SIZE(C);