Adding error

include/GooseEYE/GooseEYE.h

@@ -1282,8 +1282,8 @@ array_type::array<int> clusters(const T& f, bool periodic = true)
  * @return The image, with labels inserted (overwritten) at the positions.
  */
 template <typename T, typename U, typename V>
-[[deprecated("Will not be supported in the future. See Python warning for new API.")]]
-inline T pos2img(const T& img, const U& positions, const V& labels)
+[[deprecated("Will not be supported in the future. See Python warning for new API.")]] inline T
+pos2img(const T& img, const U& positions, const V& labels)
 {
     GOOSEEYE_WARNING_PYTHON("pos2img(img, positions, labels) deprecated, use: "
                             "i = ravel_multi_index(positions.T, img.shape); img.flat[i] = labels")
@@ -1330,6 +1330,9 @@ template <class T, class W = decltype(nullptr)>
 array_type::tensor<double, 2>
 labels_centers(const T& labels, const W& weights = nullptr, bool periodic = true)
 {
+    if (weights != nullptr) {
+        throw std::runtime_error("Please open a PR to use ``weights``.");
+    }
     static_assert(std::is_integral<typename T::value_type>::value, "Integral labels required.");
 
     GOOSEEYE_ASSERT(labels.dimension() > 0, std::out_of_range);