//
// Copyright 2012 Christian Henning, Andreas Pokorny, Lubomir Bourdev
//
// 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_METAFUNCTIONS_GET_NUM_BITS_HPP
#define BOOST_GIL_EXTENSION_TOOLBOX_METAFUNCTIONS_GET_NUM_BITS_HPP

#include <boost/gil/channel.hpp>

#include <boost/mpl/and.hpp>
#include <boost/mpl/int.hpp>
#include <boost/mpl/not.hpp>
#include <boost/mpl/size_t.hpp>
#include <boost/type_traits/is_integral.hpp>
#include <boost/type_traits/is_class.hpp>

#include <type_traits>

namespace boost{ namespace gil {

/// get_num_bits metafunctions
/// \brief Determines the numbers of bits for the given channel type.

template <typename T, class = void >
struct get_num_bits;

template< typename B, int I, int S, bool M >
struct get_num_bits< packed_channel_reference< B, I, S, M > > : mpl::int_< S >
{};

template< typename B, int I, int S, bool M >
struct get_num_bits< const packed_channel_reference< B, I, S, M > > : mpl::int_< S >
{};

template<typename B, int I, bool M>
struct get_num_bits< packed_dynamic_channel_reference< B, I, M > > : mpl::int_< I >
{};

template<typename B, int I, bool M>
struct get_num_bits< const packed_dynamic_channel_reference< B, I, M > > : mpl::int_< I >
{};

template< int N >
struct get_num_bits< packed_channel_value< N > > : mpl::int_< N >
{};

template< int N >
struct get_num_bits< const packed_channel_value< N > > : mpl::int_< N >
{};

template <typename T>
struct get_num_bits
<
    T,
    typename std::enable_if
    <
        mpl::and_
        <
            is_integral<T>,
            mpl::not_<is_class<T>>
        >::value
    >::type
> : mpl::size_t<sizeof(T) * 8>
{
};

} // namespace gil
} // namespace boost

#endif
