concepts/channel.hpp

//
// Copyright 2005-2007 Adobe Systems Incorporated
//
// 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_CONCEPTS_CHANNEL_HPP
#define BOOST_GIL_CONCEPTS_CHANNEL_HPP

#include <boost/gil/concepts/basic.hpp>
#include <boost/gil/concepts/concept_check.hpp>
#include <boost/gil/concepts/fwd.hpp>

#include <boost/concept_check.hpp>

#include <utility> // std::swap
#include <type_traits>

#if defined(BOOST_CLANG)
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wunused-local-typedefs"
#endif

#if defined(BOOST_GCC) && (BOOST_GCC >= 40900)
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wunused-local-typedefs"
#endif

namespace boost { namespace gil {

// Forward declarations
template <typename T>
struct channel_traits;

template <typename DstT, typename SrcT>
auto channel_convert(SrcT const& val)
    -> typename channel_traits<DstT>::value_type;

template <typename T>
struct ChannelConcept
{
    void constraints()
    {
        gil_function_requires<boost::EqualityComparableConcept<T>>();

        using v = typename channel_traits<T>::value_type;
        using r = typename channel_traits<T>::reference;
        using p = typename channel_traits<T>::pointer;
        using cr = typename channel_traits<T>::const_reference;
        using cp = typename channel_traits<T>::const_pointer;

        channel_traits<T>::min_value();
        channel_traits<T>::max_value();
    }

     T c;
};

namespace detail
{

template <typename T>
struct ChannelIsMutableConcept
{
    void constraints()
    {
        c1 = c2;
        using std::swap;
        swap(c1, c2);
    }
    T c1;
    T c2;
};

} // namespace detail

template <typename T>
struct MutableChannelConcept
{
    void constraints()
    {
        gil_function_requires<ChannelConcept<T>>();
        gil_function_requires<detail::ChannelIsMutableConcept<T>>();
    }
};

template <typename T>
struct ChannelValueConcept
{
    void constraints()
    {
        gil_function_requires<ChannelConcept<T>>();
        gil_function_requires<Regular<T>>();
    }
};

template <typename T1, typename T2>  // Models GIL Pixel
struct channels_are_compatible
    : std::is_same
        <
            typename channel_traits<T1>::value_type,
            typename channel_traits<T2>::value_type
        >
{
};

template <typename Channel1, typename Channel2>
struct ChannelsCompatibleConcept
{
    void constraints()
    {
        static_assert(channels_are_compatible<Channel1, Channel2>::value, "");
    }
};

template <typename SrcChannel, typename DstChannel>
struct ChannelConvertibleConcept
{
    void constraints()
    {
        gil_function_requires<ChannelConcept<SrcChannel>>();
        gil_function_requires<MutableChannelConcept<DstChannel>>();
        dst = channel_convert<DstChannel, SrcChannel>(src);
        ignore_unused_variable_warning(dst);
    }
    SrcChannel src;
    DstChannel dst;
};

}} // namespace boost::gil

#if defined(BOOST_CLANG)
#pragma clang diagnostic pop
#endif

#if defined(BOOST_GCC) && (BOOST_GCC >= 40900)
#pragma GCC diagnostic pop
#endif

#endif