lewaimai_pos_windows/include/boost/gil/extension/toolbox/metafunctions/channel_view.hpp

//
// Copyright 2010 Fabien Castan, Christian Henning
//
// Distributed under the Boost Software License, Version 1.0
// See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt
//
#ifndef BOOST_GIL_EXTENSION_TOOLBOX_CHANNEL_VIEW_HPP
#define BOOST_GIL_EXTENSION_TOOLBOX_CHANNEL_VIEW_HPP

#include <boost/gil/image_view_factory.hpp>

namespace boost {
namespace gil {

template < typename Channel
         , typename View
         >
struct channel_type_to_index
{
    static const int value = detail::type_to_index< typename color_space_type< View >::type // color (mpl::vector)
                                                  , Channel                                 // channel type
                                                  >::value;                           //< index of the channel in the color (mpl::vector)
};

template< typename Channel
        , typename View
        >
struct channel_view_type : public kth_channel_view_type< channel_type_to_index< Channel
                                                                              , View
                                                                              >::value
                                                       , View
                                                       >
{
    static const int index = channel_type_to_index< Channel
                                                  , View
                                                  >::value;

    using parent_t = kth_channel_view_type<index, View>;
    using type = typename parent_t::type;

    static type make( const View& src )
    {
        return parent_t::make( src );
    }
};

/// \ingroup ImageViewTransformationsKthChannel
template< typename Channel
        , typename View
        >
typename channel_view_type< Channel
                          , View
                          >::type channel_view( const View& src )
{
   return channel_view_type< Channel
                           , View
                           >::make( src );
}

} // namespace gil
} // namespace boost

#endif