Re: [Boost-users] [GIL] Warnings when compiling items in channel_algorithms.hpp

Nathan, I have updated the boost trunk with your patch. I mean the updated one we both agreed on, I believe. The patch wont make into boost 1.45. But should appear in the following versions. I just need to remember to update boost_release branch once the current release is done. ;-) Thanks for your help, Christian On Mon, Jun 21, 2010 at 6:11 PM, Nathan Crookston wrote:

Hi Christian,

Thanks for looking over my patch.  With a minor amount of tweaking of your code and my sample program, I was able to compile both my sample program and my reasonably extensive work code.

The only difference between what you suggested and what I'm posting is the addition of some explicit construction calls:

Index: channel_algorithm.hpp =================================================================== --- channel_algorithm.hpp (revision 63088) +++ channel_algorithm.hpp (working copy) @@ -250,11 +250,12 @@  template  struct channel_converter_unsigned_integral_nondivisible {     DstChannelV operator()(SrcChannelV src) const { -        typedef typename unsigned_integral_max_value<SrcChannelV>::value_type integer_t; +        typedef typename unsigned_integral_max_value<SrcChannelV>::value_type src_integer_t; +        typedef typename unsigned_integral_max_value<DstChannelV>::value_type dst_integer_t;

        static const double div = unsigned_integral_max_value<SrcChannelV>::value / double(unsigned_integral_max_value<DstChannelV>::value); -        static const integer_t div2 = integer_t(div/2); -        return DstChannelV((src + div2) / div); +        static const src_integer_t div2 = static_cast(div/2); +        return DstChannelV(static_cast((src + div2) / div));     }  };

@@ -265,7 +266,10 @@  /////////////////////////////////////////////////////

 template <typename DstChannelV> struct channel_converter_unsigned : public std::unary_function { -    DstChannelV   operator()(bits32f x) const { return DstChannelV(x*channel_traits<DstChannelV>::max_value()+0.5f); } +    DstChannelV   operator()(bits32f x) const { +      typedef typename detail::unsigned_integral_max_value<DstChannelV>::value_type dst_integer_t; +      return DstChannelV(static_cast(x*channel_traits<DstChannelV>::max_value()+0.5f)); +    }  };

 template <typename SrcChannelV> struct channel_converter_unsigned : public std::unary_function {

My sample program required the following modification:

FROM:  template <>   struct unsigned_integral_max_value<bits14>     : public mpl::integral_c {}; TO:

 template <>   struct unsigned_integral_max_value<bits14>     : public mpl::integral_c {};

This makes the specialization of unsigned_integral_max_value different from the others in channel_algorithm.hpp -- they use uint32_t and uintmax_t, even for 8 and 16 bit types.  This appears to be intentional, as changing them to match their arguments results in a compile error (and many tricky const initialization problems).  This makes me wonder if the unsigned_integral_max_value<>::value_type was intended to be used that way.

I wonder if there's value in a metafunction that returns the type we expect to construct our channel from (similar to the suggested base_channel).  This isn't a critical issue for me, however, as your suggestions are working well for me now.

Thanks! Nate _______________________________________________ Boost-users mailing list Boost-users@lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users