#ifndef BOOST_METAPARSE_V1_CPP98_IMPL_NTH_OF_C_IMPL_HPP
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#define BOOST_METAPARSE_V1_CPP98_IMPL_NTH_OF_C_IMPL_HPP
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// Copyright Abel Sinkovics (abel@sinkovics.hu) 2013.
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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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#include <boost/metaparse/v1/cpp98/impl/skip_seq.hpp>
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#include <boost/mpl/front.hpp>
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#include <boost/mpl/pop_front.hpp>
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#include <boost/mpl/fold.hpp>
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namespace boost
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{
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namespace metaparse
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{
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namespace v1
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{
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namespace impl
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{
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template <int N, class Seq>
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struct nth_of_c_impl
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{
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private:
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template <class NextResult>
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struct apply_unchecked :
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nth_of_c_impl<
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N - 1,
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typename boost::mpl::pop_front<Seq>::type
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>::template apply<
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typename get_remaining<NextResult>::type,
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typename get_position<NextResult>::type
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>
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{};
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public:
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typedef nth_of_c_impl type;
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template <class S, class Pos>
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struct apply :
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boost::mpl::eval_if<
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typename is_error<
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typename boost::mpl::front<Seq>::type::template apply<S, Pos>
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>::type,
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typename boost::mpl::front<Seq>::type::template apply<S, Pos>,
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apply_unchecked<
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typename boost::mpl::front<Seq>::type::template apply<S, Pos>
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>
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>
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{};
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};
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template <class Seq>
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struct nth_of_c_impl<0, Seq>
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{
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typedef nth_of_c_impl type;
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template <class S, class Pos>
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struct apply :
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boost::mpl::fold<
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typename boost::mpl::pop_front<Seq>::type,
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typename boost::mpl::front<Seq>::type::template apply<
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S,
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Pos
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>::type,
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skip_seq
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>
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{};
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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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