forked from boostorg/mpl
58 lines
1.5 KiB
C++
58 lines
1.5 KiB
C++
//-----------------------------------------------------------------------------
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// boost mpl/empty_base.hpp header file
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// See http://www.boost.org for updates, documentation, and revision history.
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//-----------------------------------------------------------------------------
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//
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// Copyright (c) 2001-02
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// Aleksey Gurtovoy
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//
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// Distributed under the Boost Software License, Version 1.0. (See
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// 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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#ifndef BOOST_MPL_EMPTY_BASE_HPP_INCLUDED
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#define BOOST_MPL_EMPTY_BASE_HPP_INCLUDED
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#include "boost/type_traits/is_empty.hpp"
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#include "boost/mpl/bool.hpp"
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#include "boost/config.hpp"
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// should be always the last #include directive
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#include "boost/type_traits/detail/bool_trait_def.hpp"
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namespace boost {
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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 defined(BOOST_MSVC) && 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 defined(BOOST_MSVC) && BOOST_MSVC < 1300
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using true_::value;
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#endif
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};
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} // namespace mpl
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BOOST_TT_AUX_BOOL_TRAIT_SPEC1(is_empty, mpl::empty_base, true)
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} // namespace boost
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#include "boost/type_traits/detail/bool_trait_undef.hpp"
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#endif // BOOST_MPL_EMPTY_BASE_HPP_INCLUDED
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