145 lines
3.5 KiB
Plaintext
145 lines
3.5 KiB
Plaintext
|
|
#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.
|
|
|
|
// $Id$
|
|
// $Date$
|
|
// $Revision$
|
|
|
|
#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
|