Boost C++ Libraries

boost/spirit/home/support/handles_container.hpp

/*=============================================================================
    Copyright (c) 2001-2011 Hartmut Kaiser

    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)
==============================================================================*/
#if !defined(BOOST_SPIRIT_HANDLES_CONTAINER_DEC_18_2010_0920AM)
#define BOOST_SPIRIT_HANDLES_CONTAINER_DEC_18_2010_0920AM

#if defined(_MSC_VER)
#pragma once
#endif

#include <boost/spirit/home/support/attributes_fwd.hpp>
#include <boost/mpl/bool.hpp>
#include <boost/mpl/or.hpp>
#include <boost/mpl/not.hpp>
#include <boost/mpl/find_if.hpp>
#include <boost/type_traits/is_same.hpp>

namespace boost { namespace spirit { namespace traits
{
    // Finds out whether a component handles container attributes intrinsically
    // (or whether container attributes need to be split up separately).
    template <typename T, typename Attribute, typename Context
            , typename Iterator, typename Enable>
    struct handles_container : mpl::false_ {};

    template <typename Subject, typename Attribute, typename Context
            , typename Iterator>
    struct unary_handles_container
      : handles_container<Subject, Attribute, Context, Iterator> {};

    template <typename Left, typename Right, typename Attribute
            , typename Context, typename Iterator>
    struct binary_handles_container 
      : mpl::or_<
            handles_container<Left, Attribute, Context, Iterator>
          , handles_container<Right, Attribute, Context, Iterator> > 
    {};

    template <typename Elements, typename Attribute, typename Context
            , typename Iterator>
    struct nary_handles_container
      : mpl::not_<
            is_same<
                typename mpl::find_if<
                    Elements, handles_container<mpl::_, Attribute
                                              , Context, Iterator> 
                >::type
              , typename mpl::end<Elements>::type> > 
    {};
}}}

#endif