C中的异或(Exclusive - OR)

 

static PyObject * int_add(PyIntObject *v, PyIntObject *w) { register long a, b, x; CONVERT_TO_LONG(v, a); CONVERT_TO_LONG(w, b); x = a + b; if ((x^a) >= 0 || (x^b) >= 0) return PyInt_FromLong(x); return PyLong_Type.tp_as_number->nb_add((PyObject *)v, (PyObject *)w); }