struct S {
    char c;
    int i;
    void *p;
};

struct S arr[2];

int size_S(void) { return (int)sizeof(struct S); }
int off_i(void) { return (int)__builtin_offsetof(struct S, i); }
int off_p(void) { return (int)__builtin_offsetof(struct S, p); }
int stride(void) { return (int)((char *)&arr[1] - (char *)&arr[0]); }