64 lines
1.4 KiB
C++
64 lines
1.4 KiB
C++
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#ifndef BOOST_MPL_EMPTY_BASE_HPP_INCLUDED
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#define BOOST_MPL_EMPTY_BASE_HPP_INCLUDED
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// Copyright Aleksey Gurtovoy 2001-2004
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//
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// Distributed under the Boost Software License, Version 1.0.
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// (See accompanying file LICENSE_1_0.txt or copy at
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// http://www.boost.org/LICENSE_1_0.txt)
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//
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// See http://www.boost.org/libs/mpl for documentation.
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// $Id$
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// $Date$
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// $Revision$
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#include <boost/mpl/bool.hpp>
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#include <boost/mpl/aux_/config/msvc.hpp>
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#include <boost/mpl/aux_/config/workaround.hpp>
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#include <boost/mpl/aux_/lambda_support.hpp>
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#include <boost/type_traits/integral_constant.hpp>
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#include <boost/type_traits/is_empty.hpp>
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namespace boost { namespace mpl {
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// empty base class, guaranteed to have no members; inheritance from
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// 'empty_base' through the 'inherit' metafunction is a no-op - see
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// "mpl/inherit.hpp> header for the details
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struct empty_base {};
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template< typename T >
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struct is_empty_base
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: false_
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{
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#if BOOST_WORKAROUND(BOOST_MSVC, < 1300)
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using false_::value;
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#endif
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};
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template<>
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struct is_empty_base<empty_base>
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: true_
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{
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#if BOOST_WORKAROUND(BOOST_MSVC, < 1300)
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using true_::value;
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#endif
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};
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}}
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namespace boost {
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template<> struct is_empty< mpl::empty_base >
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: public ::boost::integral_constant<bool,true>
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{
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public:
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BOOST_MPL_AUX_LAMBDA_SUPPORT_SPEC(1,is_empty,(mpl::empty_base))
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};
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}
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#endif // BOOST_MPL_EMPTY_BASE_HPP_INCLUDED
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