
#ifndef BOOST_NETWORK_MESSAGE_MODIFIER_ADD_HEADER_HPP_20100824
#define BOOST_NETWORK_MESSAGE_MODIFIER_ADD_HEADER_HPP_20100824

// Copyright 2010 (c) Dean Michael Berris
// 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)

#include <boost/network/support/is_async.hpp>
#include <boost/network/support/is_pod.hpp>
#include <boost/utility/enable_if.hpp>
#include <boost/mpl/and.hpp>
#include <boost/mpl/not.hpp>

namespace boost { namespace network {

    namespace impl {
        template <class Message, class KeyType, class ValueType, class Tag>
        inline typename enable_if<
            mpl::and_<
                mpl::not_<is_pod<Tag> >
                , mpl::not_<is_async<Tag> >
                >
            , void
            >::type
        add_header(Message & message, KeyType const & key, ValueType const & value, Tag) {
            message.headers().insert(std::make_pair(key, value));
        }

        template <class Message, class KeyType, class ValueType, class Tag>
        inline typename enable_if<
            mpl::and_<
                mpl::not_<is_pod<Tag> >
                , is_async<Tag>
                >
            , void
            >::type
        add_header(Message & message, KeyType const & key, ValueType const & value, Tag) {
            typedef typename Message::header_type header_type;
            message.add_header(header_type(key,value));
        }

        template <class Message, class KeyType, class ValueType, class Tag>
        inline typename enable_if<
            is_pod<Tag>
            , void
        >::type
        add_header(Message & message, KeyType const & key, ValueType const & value, Tag) {
            typename Message::header_type header = { key, value };
            message.headers.insert(message.headers.end(), header);
        }

    }

    template <class Tag, template <class> class Message, class KeyType, class ValueType>
    inline void add_header(Message<Tag> & message, KeyType const & key, ValueType const & value) {
        impl::add_header(message, key, value, Tag());
    }

} // namespace network

} // namespace boost

#endif // BOOST_NETWORK_MESSAGE_MODIFIER_ADD_HEADER_HPP_20100824
