+ if (n == -1) {
+ PyErr_SetString(PyExc_RuntimeError,
+ "an error occurred in isl_basic_set_n_constraint");
+ return NULL;
+ }
+ pointers = PyList_New(n);
+ if (pointers == NULL) {
+ return NULL;
+ }
+ list = malloc(sizeof(pointer_list));
+ if (list == NULL) {
+ Py_DECREF(pointers);
+ return PyErr_NoMemory();
+ }