linux下编程用 编译软件

				// Test that we can refer to the address of a base member of a null pointer				// to get its offset.  The standard says that offsetof shall not be used on				// non-POD classes, but there seems to be no such restriction on the common				// implementation thereof.								// Yes, this is bad, naughty, evil code.  But it seems to be well-formed.				// So we'll just warn.								// { dg-do run }								struct A { int i; };								struct B: public A {				  virtual void f ();				};								struct C: public B { };								int main ()				{				  return ((unsigned long) &((C*)0)->i) != sizeof(void*); // { dg-warning "offsetof|invalid" "" }				}