98 lines
3.1 KiB
Plaintext
98 lines
3.1 KiB
Plaintext
/*=============================================================================
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Copyright (c) 2001-2011 Joel de Guzman
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Copyright (c) 2006 Dan Marsden
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Distributed under the Boost Software License, Version 1.0. (See accompanying
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file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
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==============================================================================*/
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#if !defined(FUSION_AT_IMPL_20060124_1933)
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#define FUSION_AT_IMPL_20060124_1933
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#include <boost/fusion/support/config.hpp>
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#include <boost/fusion/container/vector.hpp>
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#include <boost/fusion/sequence/intrinsic/at.hpp>
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#include <boost/fusion/container/vector/convert.hpp>
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#include <boost/fusion/algorithm/transformation/transform.hpp>
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#include <boost/type_traits/remove_reference.hpp>
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#include <boost/type_traits/is_reference.hpp>
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#include <boost/mpl/assert.hpp>
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#include <boost/fusion/support/unused.hpp>
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#include <boost/mpl/eval_if.hpp>
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#include <boost/mpl/identity.hpp>
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#include <boost/type_traits/is_same.hpp>
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namespace boost { namespace fusion
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{
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struct zip_view_tag;
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namespace detail
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{
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template<typename N>
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struct poly_at
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{
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template<typename T>
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struct result;
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template<typename N1, typename SeqRef>
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struct result<poly_at<N1>(SeqRef)>
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: mpl::eval_if<is_same<SeqRef, unused_type const&>,
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mpl::identity<unused_type>,
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result_of::at<typename remove_reference<SeqRef>::type, N> >
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{
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BOOST_MPL_ASSERT((is_reference<SeqRef>));
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};
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template<typename Seq>
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BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
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typename result<poly_at(Seq&)>::type
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operator()(Seq& seq) const
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{
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return fusion::at<N>(seq);
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}
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template<typename Seq>
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BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
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typename result<poly_at(Seq const&)>::type
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operator()(Seq const& seq) const
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{
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return fusion::at<N>(seq);
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}
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BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
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unused_type operator()(unused_type const&) const
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{
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return unused_type();
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}
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};
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}
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namespace extension
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{
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template<typename Tag>
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struct at_impl;
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template<>
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struct at_impl<zip_view_tag>
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{
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template<typename Seq, typename N>
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struct apply
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{
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typedef typename result_of::as_vector<
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typename result_of::transform<
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typename Seq::sequences, detail::poly_at<N> >::type>::type type;
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BOOST_CONSTEXPR BOOST_FUSION_GPU_ENABLED
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static type
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call(Seq& seq)
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{
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return type(
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fusion::transform(seq.sequences_, detail::poly_at<N>()));
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}
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};
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};
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}
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}}
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#endif
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