python: add TODOs for converting more asserts to Python exceptions.

Currently not possible to do as the image data size utils are in private
headers. The whole Image internals are due for a rework anyway, so just
wait until that's done.

src/python/magnum/magnum.cpp

@@ -93,9 +93,13 @@ template<class T> void imageView(py::class_<T, PyImageViewHolder<T>>& c) {
     c
         /* Constructors */
         .def(py::init([](const PixelStorage& storage, PixelFormat format, const typename PyDimensionTraits<T::Dimensions, Int>::VectorType& size, const Containers::ArrayView<typename T::Type>& data) {
+            /** @todo check and fire an exception for too small data array,
+                once that's available in a non-internal API */
             return pyImageViewHolder(T{storage, format, size, data}, pyObjectHolderFor<Containers::PyArrayViewHolder>(data).owner);
         }), "Constructor")
         .def(py::init([](PixelFormat format, const typename PyDimensionTraits<T::Dimensions, Int>::VectorType& size, const Containers::ArrayView<typename T::Type>& data) {
+            /** @todo check and fire an exception for too small data array,
+                once that's available in a non-internal API */
             return pyImageViewHolder(T{format, size, data}, pyObjectHolderFor<Containers::PyArrayViewHolder>(data).owner);
         }), "Constructor")
         .def(py::init([](const PixelStorage& storage, PixelFormat format, const typename PyDimensionTraits<T::Dimensions, Int>::VectorType& size) {
@@ -183,6 +187,8 @@ template<class T> void compressedImageView(py::class_<T, PyImageViewHolder<T>>&
             return T{format, size};
         }), "Construct an empty view")
         .def(py::init([](CompressedPixelFormat format, const typename PyDimensionTraits<T::Dimensions, Int>::VectorType& size, const Containers::ArrayView<typename T::Type>& data) {
+            /** @todo check and fire an exception for too small data array,
+                once that's available in a non-internal API */
             return pyImageViewHolder(T{format, size, data}, pyObjectHolderFor<Containers::PyArrayViewHolder>(data).owner);
         }), "Constructor")
         .def(py::init([](CompressedImage<T::Dimensions>& image) {