Document why Image*::size() is returning a const&.

src/Magnum/Image.h

@@ -405,6 +405,9 @@ template<UnsignedInt dimensions> class Image {
         UnsignedInt pixelSize() const { return _pixelSize; }
 
         /** @brief Image size in pixels */
+        /* Unlike other getters this one is a const& so it's possible to slice
+           to the sizes when all images are in an array, for example for use
+           in TextureTools atlas APIs */
         const VectorTypeFor<dimensions, Int>& size() const { return _size; }
 
         /**
@@ -661,6 +664,9 @@ template<UnsignedInt dimensions> class CompressedImage {
         CompressedPixelFormat format() const { return _format; }
 
         /** @brief Image size in pixels */
+        /* Unlike other getters this one is a const& so it's possible to slice
+           to the sizes when all images are in an array, for example for use
+           in TextureTools atlas APIs */
         const VectorTypeFor<dimensions, Int>& size() const { return _size; }
 
         /**

src/Magnum/ImageView.h

@@ -452,6 +452,9 @@ template<UnsignedInt dimensions, class T> class ImageView {
         UnsignedInt pixelSize() const { return _pixelSize; }
 
         /** @brief Image size in pixels */
+        /* Unlike other getters this one is a const& so it's possible to slice
+           to the sizes when all images are in an array, for example for use
+           in TextureTools atlas APIs */
         const VectorTypeFor<dimensions, Int>& size() const { return _size; }
 
         /**
@@ -837,6 +840,9 @@ template<UnsignedInt dimensions, class T> class CompressedImageView {
         CompressedPixelFormat format() const { return _format; }
 
         /** @brief Image size in pixels */
+        /* Unlike other getters this one is a const& so it's possible to slice
+           to the sizes when all images are in an array, for example for use
+           in TextureTools atlas APIs */
         const VectorTypeFor<dimensions, Int>& size() const { return _size; }
 
         /**

src/Magnum/Trade/ImageData.h

@@ -757,6 +757,9 @@ template<UnsignedInt dimensions> class ImageData {
         UnsignedInt pixelSize() const;
 
         /** @brief Image size in pixels */
+        /* Unlike other getters this one is a const& so it's possible to slice
+           to the sizes when all images are in an array, for example for use
+           in TextureTools atlas APIs */
         const VectorTypeFor<dimensions, Int>& size() const { return _size; }
 
         /**