#ifndef BOOST_METAPARSE_V1_CPP11_IMPL_NTH_OF_C_HPP
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#define BOOST_METAPARSE_V1_CPP11_IMPL_NTH_OF_C_HPP
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// Copyright Abel Sinkovics (abel@sinkovics.hu) 2017.
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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/cpp11/impl/nth_of_c_skip_remaining.hpp>
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#include <boost/metaparse/v1/is_error.hpp>
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#include <boost/metaparse/v1/get_remaining.hpp>
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#include <boost/metaparse/v1/get_position.hpp>
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#include <boost/metaparse/v1/get_result.hpp>
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#include <type_traits>
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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 S, class Pos, class... Ps>
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struct nth_of_c;
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template <int N, class S, class Pos, class P, class... Ps>
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struct nth_of_c<N, S, Pos, P, Ps...>
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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<
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N - 1,
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typename get_remaining<NextResult>::type,
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typename get_position<NextResult>::type,
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Ps...
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>
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{};
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public:
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typedef
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typename std::conditional<
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is_error<typename P::template apply<S, Pos>>::type::value,
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typename P::template apply<S, Pos>,
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apply_unchecked<typename P::template apply<S, Pos>>
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>::type::type
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type;
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};
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template <class P, class S, class Pos, class... Ps>
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struct nth_of_c<0, S, Pos, P, Ps...>
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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_skip_remaining<
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typename get_result<NextResult>::type,
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typename get_remaining<NextResult>::type,
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typename get_position<NextResult>::type,
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Ps...
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>
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{};
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public:
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typedef
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typename std::conditional<
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is_error<typename P::template apply<S, Pos>>::type::value,
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typename P::template apply<S, Pos>,
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apply_unchecked<typename P::template apply<S, Pos>>
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>::type::type
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type;
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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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