ext-boost/boost/mpl/vector/aux_/at.hpp
2019-08-24 15:39:04 +02:00

117 lines
2.5 KiB
C++

#ifndef BOOST_MPL_VECTOR_AUX_AT_HPP_INCLUDED
#define BOOST_MPL_VECTOR_AUX_AT_HPP_INCLUDED
// Copyright Aleksey Gurtovoy 2000-2004
//
// 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/vector/aux_/tag.hpp>
#include <boost/mpl/long.hpp>
#include <boost/mpl/void.hpp>
#include <boost/mpl/aux_/nttp_decl.hpp>
#include <boost/mpl/aux_/type_wrapper.hpp>
#include <boost/mpl/aux_/value_wknd.hpp>
#include <boost/mpl/aux_/config/typeof.hpp>
#include <boost/mpl/aux_/config/ctps.hpp>
namespace boost { namespace mpl {
#if defined(BOOST_MPL_CFG_TYPEOF_BASED_SEQUENCES)
template< typename Vector, long n_ >
struct v_at_impl
{
typedef long_< (Vector::lower_bound_::value + n_) > index_;
typedef __typeof__( Vector::item_(index_()) ) type;
};
template< typename Vector, long n_ >
struct v_at
: aux::wrapped_type< typename v_at_impl<Vector,n_>::type >
{
};
template<>
struct at_impl< aux::vector_tag >
{
template< typename Vector, typename N > struct apply
: v_at<
Vector
, BOOST_MPL_AUX_VALUE_WKND(N)::value
>
{
};
};
#else
# if !defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION) \
&& !defined(BOOST_MPL_CFG_NO_NONTYPE_TEMPLATE_PARTIAL_SPEC)
template< typename Vector, BOOST_MPL_AUX_NTTP_DECL(long, n_) > struct v_at;
template< BOOST_MPL_AUX_NTTP_DECL(long, n_) >
struct at_impl< aux::vector_tag<n_> >
{
template< typename Vector, typename N > struct apply
#if !defined(__BORLANDC__)
: v_at<
Vector
, BOOST_MPL_AUX_VALUE_WKND(N)::value
>
{
#else
{
typedef typename v_at<
Vector
, BOOST_MPL_AUX_VALUE_WKND(N)::value
>::type type;
#endif
};
};
# else
namespace aux {
template< BOOST_MPL_AUX_NTTP_DECL(long, n_) > struct v_at_impl
{
template< typename V > struct result_;
};
// to work around ETI, etc.
template<> struct v_at_impl<-1>
{
template< typename V > struct result_
{
typedef void_ type;
};
};
} // namespace aux
template< typename T, BOOST_MPL_AUX_NTTP_DECL(long, n_) >
struct v_at
: aux::v_at_impl<n_>::template result_<T>
{
};
# endif // BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
#endif // BOOST_MPL_CFG_TYPEOF_BASED_SEQUENCES
}}
#endif // BOOST_MPL_VECTOR_AUX_AT_HPP_INCLUDED