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#ifndef BOOST_MPL_SEQUENCE_TAG_HPP_INCLUDED
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#define BOOST_MPL_SEQUENCE_TAG_HPP_INCLUDED
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// Copyright Aleksey Gurtovoy 2000-2004
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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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// See http://www.boost.org/libs/mpl for documentation.
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// $Id: sequence_tag.hpp 49267 2008-10-11 06:19:02Z agurtovoy $
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// $Date: 2008-10-11 02:19:02 -0400 (Sat, 11 Oct 2008) $
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#include <boost/mpl/sequence_tag_fwd.hpp>
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#include <boost/mpl/aux_/has_tag.hpp>
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#include <boost/mpl/aux_/has_begin.hpp>
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#include <boost/mpl/aux_/na_spec.hpp>
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#include <boost/mpl/aux_/is_msvc_eti_arg.hpp>
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#include <boost/mpl/aux_/config/eti.hpp>
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#include <boost/mpl/aux_/yes_no.hpp>
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#include <boost/mpl/aux_/config/workaround.hpp>
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namespace boost { namespace mpl {
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// agurt, 27/nov/02: have to use a simplistic 'sequence_tag' implementation
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// on MSVC to avoid dreadful "internal structure overflow" error
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#if BOOST_WORKAROUND(BOOST_MSVC, < 1300) \
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|| defined(BOOST_MPL_CFG_NO_HAS_XXX)
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typename BOOST_MPL_AUX_NA_PARAM(Sequence)
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typedef typename Sequence::tag type;
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#elif BOOST_WORKAROUND(BOOST_MSVC, == 1300)
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// agurt, 07/feb/03: workaround for what seems to be MSVC 7.0-specific ETI issue
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struct sequence_tag_impl
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template< typename Sequence > struct result_
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typedef typename Sequence::tag type;
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struct sequence_tag_impl<false>
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template< typename Sequence > struct result_
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typename BOOST_MPL_AUX_NA_PARAM(Sequence)
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: aux::sequence_tag_impl< !aux::is_msvc_eti_arg<Sequence>::value >
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::template result_<Sequence>
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template< bool has_tag_, bool has_begin_ >
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struct sequence_tag_impl
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// agurt 24/nov/02: MSVC 6.5 gets confused in 'sequence_tag_impl<true>'
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// specialization below, if we name it 'result_' here
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template< typename Sequence > struct result2_;
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# define AUX_CLASS_SEQUENCE_TAG_SPEC(has_tag, has_begin, result_type) \
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template<> struct sequence_tag_impl<has_tag,has_begin> \
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template< typename Sequence > struct result2_ \
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typedef result_type type; \
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AUX_CLASS_SEQUENCE_TAG_SPEC(true, true, typename Sequence::tag)
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AUX_CLASS_SEQUENCE_TAG_SPEC(true, false, typename Sequence::tag)
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AUX_CLASS_SEQUENCE_TAG_SPEC(false, true, nested_begin_end_tag)
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AUX_CLASS_SEQUENCE_TAG_SPEC(false, false, non_sequence_tag)
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# undef AUX_CLASS_SEQUENCE_TAG_SPEC
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typename BOOST_MPL_AUX_NA_PARAM(Sequence)
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: aux::sequence_tag_impl<
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::boost::mpl::aux::has_tag<Sequence>::value
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, ::boost::mpl::aux::has_begin<Sequence>::value
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>::template result2_<Sequence>
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BOOST_MPL_AUX_NA_SPEC(1, sequence_tag)
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#endif // BOOST_MPL_SEQUENCE_TAG_HPP_INCLUDED