channel metadata

// the declaring pixel's type
using pixel_type = PixelType;
// this type
using type = pixel_channel<pixel_type,ChannelTraits,Index,BitsToLeft>;
// the name type for the channel
using name_type = typename ChannelTraits::name_type;
// the integer type for the channel
using int_type = typename ChannelTraits::int_type;
// the floating point type for the channel
using real_type = typename ChannelTraits::real_type;
// the declaring pixel's integer type
using pixel_int_type = typename PixelType::int_type;
// the number of bits to the left of this channel
constexpr static const size_t bits_to_left = ChannelTraits::bit_depth!=0?BitsToLeft:0;
// the total bits to the right of this channel including padding
constexpr static const size_t total_bits_to_right =  ChannelTraits::bit_depth!=0?sizeof(pixel_int_type)*8-BitsToLeft-ChannelTraits::bit_depth:0;
// the bits to the right of this channel excluding padding
constexpr static const size_t bits_to_right =ChannelTraits::bit_depth!=0?total_bits_to_right-PixelType::pad_right_bits:0;
// the name of the channel
constexpr static inline const char* name() { return ChannelTraits::name(); }
// the bit depth of the channel
constexpr static const size_t bit_depth = ChannelTraits::bit_depth;
// the mask of the channel's value
constexpr static const int_type value_mask = ChannelTraits::mask;
// the mask of the channel's value within the entire pixel's value
constexpr static const pixel_int_type channel_mask = (value_mask>0)?pixel_int_type(pixel_int_type(value_mask)<<total_bits_to_right):pixel_int_type(0);
// the minimum value for the channel
constexpr static const int_type min = ChannelTraits::min;
// the maximum value for the channel
constexpr static const int_type max = ChannelTraits::max;
// the default value for the channel
constexpr static const int_type default_ = ChannelTraits::default_;
// the scale denominator
constexpr static const int_type scale = ChannelTraits::scale;
// the reciprocal of the scale denominator
constexpr static const real_type scaler = ChannelTraits::scaler;