// https://issues.dlang.org/show_bug.cgi?id=22809

typedef unsigned long size_t;

// #define __builtin_offsetof(t,i) ((size_t)((char *)&((t *)0)->i - (char *)0))

struct Foo {
    int x, y;
};

//int y = __builtin_offsetof(struct Foo, y);
//_Static_assert(__builtin_offsetof(struct Foo, y)==4, "");

int y = ((size_t)((char *)&((struct Foo *)1)->x - (char *)1));
_Static_assert(((size_t)((char *)&((struct Foo *)0)->y - (char *)0))==4, "");