* gil:
thanks for reporting those. For avoidance of doubt, would you please provide the exact compiler version and command line which generated those warnings ?
sure * on linux x86_64 with clang++ 5.0.2: clang++ -c -g3 -Wall -Wextra -Wnon-virtual-dtor -Werror=delete-non-virtual-dtor -pipe -march=native -std=c++14 -o file.o file.cpp In file included from /softs/lin64-clang-5.0.2/debug/boost/include/boost/gil/extension/io/jpeg.hpp:22: In file included from /softs/lin64-clang-5.0.2/debug/boost/include/boost/gil/extension/io/jpeg/read.hpp:24: In file included from /softs/lin64-clang-5.0.2/debug/boost/include/boost/gil/extension/io/jpeg/tags.hpp:45: In file included from /softs/lin64-clang-5.0.2/debug/boost/include/boost/gil/io/base.hpp:34: In file included from /softs/lin64-clang-5.0.2/debug/boost/include/boost/gil/extension/toolbox/toolbox.hpp:24: In file included from /softs/lin64-clang-5.0.2/debug/boost/include/boost/gil/extension/toolbox/image_types.hpp:22: /softs/lin64-clang-5.0.2/debug/boost/include/boost/gil/extension/toolbox/image_types/indexed_image.hpp:190:5: warning: 'const' type qualifier on return type has no effect [-Wignored-qualifiers] const std::size_t num_colors() const { return _num_colors; } ^~~~~~ In file included from Tools/Bitmap.cpp:10: In file included from /softs/lin64-clang-5.0.2/debug/boost/include/boost/gil/extension/io/jpeg.hpp:22: In file included from /softs/lin64-clang-5.0.2/debug/boost/include/boost/gil/extension/io/jpeg/read.hpp:24: In file included from /softs/lin64-clang-5.0.2/debug/boost/include/boost/gil/extension/io/jpeg/tags.hpp:45: In file included from /softs/lin64-clang-5.0.2/debug/boost/include/boost/gil/io/base.hpp:34: In file included from /softs/lin64-clang-5.0.2/debug/boost/include/boost/gil/extension/toolbox/toolbox.hpp:25: In file included from /softs/lin64-clang-5.0.2/debug/boost/include/boost/gil/extension/toolbox/metafunctions.hpp:22: In file included from /softs/lin64-clang-5.0.2/debug/boost/include/boost/gil/extension/toolbox/metafunctions/channel_type.hpp:29: In file included from /softs/lin64-clang-5.0.2/debug/boost/include/boost/gil/extension/toolbox/dynamic_images.hpp:27: In file included from /softs/lin64-clang-5.0.2/debug/boost/include/boost/gil/extension/dynamic_image/dynamic_image_all.hpp:26: In file included from /softs/lin64-clang-5.0.2/debug/boost/include/boost/gil/extension/dynamic_image/algorithm.hpp:16: In file included from /softs/lin64-clang-5.0.2/debug/boost/include/boost/gil/extension/dynamic_image/any_image.hpp:24: /softs/lin64-clang-5.0.2/debug/boost/include/boost/gil/extension/dynamic_image/any_image_view.hpp:41:63: warning: unused parameter 'v' [-Wunused-parameter] template <typename T> result_type operator()(const T& v) const { return num_channels<T>::value; } ^ In file included from /softs/lin64-clang-5.0.2/debug/boost/include/boost/gil/extension/io/jpeg.hpp:22: In file included from /softs/lin64-clang-5.0.2/debug/boost/include/boost/gil/extension/io/jpeg/read.hpp:24: In file included from /softs/lin64-clang-5.0.2/debug/boost/include/boost/gil/extension/io/jpeg/tags.hpp:45: In file included from /softs/lin64-clang-5.0.2/debug/boost/include/boost/gil/io/base.hpp:34: In file included from /softs/lin64-clang-5.0.2/debug/boost/include/boost/gil/extension/toolbox/toolbox.hpp:25: In file included from /softs/lin64-clang-5.0.2/debug/boost/include/boost/gil/extension/toolbox/metafunctions.hpp:22: In file included from /softs/lin64-clang-5.0.2/debug/boost/include/boost/gil/extension/toolbox/metafunctions/channel_type.hpp:29: In file included from /softs/lin64-clang-5.0.2/debug/boost/include/boost/gil/extension/toolbox/dynamic_images.hpp:27: In file included from /softs/lin64-clang-5.0.2/debug/boost/include/boost/gil/extension/dynamic_image/dynamic_image_all.hpp:26: /softs/lin64-clang-5.0.2/debug/boost/include/boost/gil/extension/dynamic_image/algorithm.hpp:147:70: warning: unused parameter 'src' [-Wunused-parameter] template <typename V, typename Value> static void apply(const V& src, const Value& val) { throw std::bad_cast();} ^ /softs/lin64-clang-5.0.2/debug/boost/include/boost/gil/extension/dynamic_image/algorithm.hpp:147:88: warning: unused parameter 'val' [-Wunused-parameter] template <typename V, typename Value> static void apply(const V& src, const Value& val) { throw std::bad_cast();} In file included from /softs/lin64-clang-5.0.2/debug/boost/include/boost/gil/extension/io/jpeg.hpp:22: In file included from /softs/lin64-clang-5.0.2/debug/boost/include/boost/gil/extension/io/jpeg/read.hpp:24: In file included from /softs/lin64-clang-5.0.2/debug/boost/include/boost/gil/extension/io/jpeg/tags.hpp:45: In file included from /softs/lin64-clang-5.0.2/debug/boost/include/boost/gil/io/base.hpp:34: In file included from /softs/lin64-clang-5.0.2/debug/boost/include/boost/gil/extension/toolbox/toolbox.hpp:25: In file included from /softs/lin64-clang-5.0.2/debug/boost/include/boost/gil/extension/toolbox/metafunctions.hpp:22: In file included from /softs/lin64-clang-5.0.2/debug/boost/include/boost/gil/extension/toolbox/metafunctions/channel_type.hpp:29: In file included from /softs/lin64-clang-5.0.2/debug/boost/include/boost/gil/extension/toolbox/dynamic_images.hpp:27: In file included from /softs/lin64-clang-5.0.2/debug/boost/include/boost/gil/extension/dynamic_image/dynamic_image_all.hpp:30: /softs/lin64-clang-5.0.2/debug/boost/include/boost/gil/extension/dynamic_image/image_view_factory.hpp:178:140: warning: unused parameter 'cc' [-Wunused-parameter] typename color_converted_view_type<any_image_view<ViewTypes>, DstP, CC>::type color_converted_view(const any_image_view<ViewTypes>& src,CC cc) {~ ^ /softs/lin64-clang-5.0.2/debug/boost/include/boost/gil/extension/dynamic_image/image_view_factory.hpp:201:144: warning: unused parameter 'cc' [-Wunused-parameter] typename color_converted_view_type<any_image_view<ViewTypes>, DstP, CC>::type any_color_converted_view(const any_image_view<ViewTypes>& src,CC cc) {~ ^ In file included from /softs/lin64-clang-5.0.2/debug/boost/include/boost/gil/extension/io/jpeg.hpp:22: In file included from /softs/lin64-clang-5.0.2/debug/boost/include/boost/gil/extension/io/jpeg/read.hpp:26: In file included from /softs/lin64-clang-5.0.2/debug/boost/include/boost/gil/extension/io/jpeg/detail/read.hpp:29: /softs/lin64-clang-5.0.2/debug/boost/include/boost/gil/io/device.hpp:446:31: warning: unused parameter 'data' [-Wunused-parameter] void write( const byte_t* data ^ /softs/lin64-clang-5.0.2/debug/boost/include/boost/gil/io/device.hpp:447:31: warning: unused parameter 'count' [-Wunused-parameter] , std::size_t count ) ^ /softs/lin64-clang-5.0.2/debug/boost/include/boost/gil/io/device.hpp:471:35: warning: unused parameter 'data' [-Wunused-parameter] std::size_t read( byte_t* data ^ /softs/lin64-clang-5.0.2/debug/boost/include/boost/gil/io/device.hpp:472:35: warning: unused parameter 'count' [-Wunused-parameter] , std::size_t count ) ^ * on linux x86_64 with g++ 8.2.0: g++-8.2.0 -c -g3 -Wall -Wextra -Wnon-virtual-dtor -Werror=delete-non-virtual-dtor -pipe -march=native -std=c++14 -o file.o file.cpp In file included from /softs/lin64-gcc-8.2.0/debug/boost/include/boost/gil/extension/toolbox/image_types.hpp:22, from /softs/lin64-gcc-8.2.0/debug/boost/include/boost/gil/extension/toolbox/toolbox.hpp:24, from /softs/lin64-gcc-8.2.0/debug/boost/include/boost/gil/io/base.hpp:34, from /softs/lin64-gcc-8.2.0/debug/boost/include/boost/gil/extension/io/jpeg/tags.hpp:45, from /softs/lin64-gcc-8.2.0/debug/boost/include/boost/gil/extension/io/jpeg/read.hpp:24, from /softs/lin64-gcc-8.2.0/debug/boost/include/boost/gil/extension/io/jpeg.hpp:22, /softs/lin64-gcc-8.2.0/debug/boost/include/boost/gil/extension/toolbox/image_types/indexed_image.hpp:190:5: warning: les qualificatifs de type sont ignorés sur le type retourné par la fonction [-Wignored-qualifiers] const std::size_t num_colors() const { return _num_colors; } ^~~~~ Kind regards, Frédéric