#ifndef BOOST_MPL_MAP_AUX_AT_IMPL_HPP_INCLUDED | |
#define BOOST_MPL_MAP_AUX_AT_IMPL_HPP_INCLUDED | |
// Copyright Aleksey Gurtovoy 2003-2004 | |
// Copyright David Abrahams 2003-2004 | |
// | |
// 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) | |
// | |
// See http://www.boost.org/libs/mpl for documentation. | |
// $Id: at_impl.hpp 49267 2008-10-11 06:19:02Z agurtovoy $ | |
// $Date: 2008-10-11 02:19:02 -0400 (Sat, 11 Oct 2008) $ | |
// $Revision: 49267 $ | |
#include <boost/mpl/at_fwd.hpp> | |
#include <boost/mpl/long.hpp> | |
#include <boost/mpl/map/aux_/tag.hpp> | |
#include <boost/mpl/aux_/order_impl.hpp> | |
#include <boost/mpl/aux_/overload_names.hpp> | |
#include <boost/mpl/aux_/type_wrapper.hpp> | |
#include <boost/mpl/aux_/ptr_to_ref.hpp> | |
#include <boost/mpl/aux_/static_cast.hpp> | |
#include <boost/mpl/aux_/config/typeof.hpp> | |
#include <boost/mpl/aux_/config/ctps.hpp> | |
#if !defined(BOOST_MPL_CFG_TYPEOF_BASED_SEQUENCES) | |
# include <boost/mpl/eval_if.hpp> | |
# include <boost/mpl/pair.hpp> | |
# include <boost/mpl/void.hpp> | |
# include <boost/mpl/aux_/config/static_constant.hpp> | |
#endif | |
namespace boost { namespace mpl { | |
#if defined(BOOST_MPL_CFG_TYPEOF_BASED_SEQUENCES) | |
template< typename Map, typename Key > | |
struct m_at | |
{ | |
typedef aux::type_wrapper<Key> key_; | |
typedef __typeof__( BOOST_MPL_AUX_OVERLOAD_CALL_VALUE_BY_KEY( | |
Map | |
, BOOST_MPL_AUX_STATIC_CAST(key_*, 0) | |
) ) type; | |
}; | |
template<> | |
struct at_impl< aux::map_tag > | |
{ | |
template< typename Map, typename Key > struct apply | |
: aux::wrapped_type< typename m_at< | |
Map | |
, Key | |
>::type > | |
{ | |
}; | |
}; | |
// agurt 31/jan/04: two-step implementation for the sake of GCC 3.x | |
template< typename Map, long order > | |
struct item_by_order_impl | |
{ | |
typedef __typeof__( BOOST_MPL_AUX_OVERLOAD_CALL_ITEM_BY_ORDER( | |
Map | |
, BOOST_MPL_AUX_STATIC_CAST(long_<order>*, 0) | |
) ) type; | |
}; | |
template< typename Map, long order > | |
struct item_by_order | |
: aux::wrapped_type< | |
typename item_by_order_impl<Map,order>::type | |
> | |
{ | |
}; | |
#else // BOOST_MPL_CFG_TYPEOF_BASED_SEQUENCES | |
# if !defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION) | |
template< typename Map, long n > struct m_at | |
{ | |
typedef void_ type; | |
}; | |
# else | |
template< long n > struct m_at_impl | |
{ | |
template< typename Map > struct result_ | |
{ | |
typedef void_ type; | |
}; | |
}; | |
template< typename Map, long n > struct m_at | |
{ | |
typedef typename m_at_impl<n>::result_<Map>::type type; | |
}; | |
# endif | |
template<> | |
struct at_impl< aux::map_tag > | |
{ | |
template< typename Map, typename Key > struct apply | |
{ | |
typedef typename m_at< Map, (x_order_impl<Map,Key>::value - 2) >::type item_; | |
typedef typename eval_if< | |
is_void_<item_> | |
, void_ | |
, second<item_> | |
>::type type; | |
}; | |
}; | |
template< typename Map, long order > struct is_item_masked | |
{ | |
BOOST_STATIC_CONSTANT(bool, value = | |
sizeof( BOOST_MPL_AUX_OVERLOAD_CALL_IS_MASKED( | |
Map | |
, BOOST_MPL_AUX_STATIC_CAST(long_<order>*, 0) | |
) ) == sizeof(aux::yes_tag) | |
); | |
}; | |
template< typename Map, long order > struct item_by_order | |
{ | |
typedef typename eval_if_c< | |
is_item_masked<Map,order>::value | |
, void_ | |
, m_at<Map,(order - 2)> | |
>::type type; | |
}; | |
#endif | |
}} | |
#endif // BOOST_MPL_SET_AUX_AT_IMPL_HPP_INCLUDED |