Function operator-

mlx/ops.cpp:2787–2789

      a.shape(), a.dtype(), std::make_shared<Negative>(to_stream(s)), {a});
}
array operator-(const array& a) {
  return negative(a);
}

array sign(const array& a, StreamOrDevice s /* = {} */) {
  return array(a.shape(), a.dtype(), std::make_shared<Sign>(to_stream(s)), {a});