of an `ndarray`.

  If obj is an `ndarray`, it is assumed to be contiguous.

  If the specified len==-1, str must be null-terminated.
*/
static int try_pyarr_from_string(PyObject *obj,
                                 const string str, const int len) {
#ifdef DEBUGCFUNCS
fprintf(stderr, "try_pyarr_from_string(str='%s', len=%d, obj=%p)\n",
        (char*)str,len, obj);
#endif
    if (PyArray_Check(obj)) {
        PyArrayObject *arr = (PyArrayObject *)obj;
        assert(ISCONTIGUOUS(arr));
        string buf = PyArray_DATA(arr);
        npy_intp n = len;
        if (n == -1) {
            /* Assuming null-terminated str. */
            n = strlen(str);
        }
        if (n > PyArray_NBYTES(arr)) {
            n = PyArray_NBYTES(arr);
        }
        STRINGCOPYN(buf, str, n);
        return 1;
    }
capi_fail:
    PRINTPYOBJERR(obj);
    PyErr_SetString(#modulename#_error, "try_pyarr_from_string failed");
    return 0;
}
)