python3_sys::PySlice_GetIndicesEx

pub unsafe extern fn PySlice_GetIndicesEx(r: *mut PyObject, length: Py_ssize_t, start: *mut Py_ssize_t, stop: *mut Py_ssize_t, step: *mut Py_ssize_t, slicelength: *mut Py_ssize_t) -> c_int