57 lines
1.5 KiB
C++
57 lines
1.5 KiB
C++
#ifndef BOOST_METAPARSE_V1_CPP11_ONE_OF_HPP
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#define BOOST_METAPARSE_V1_CPP11_ONE_OF_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/is_error.hpp>
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#include <boost/metaparse/v1/fail.hpp>
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#include <boost/metaparse/v1/cpp11/impl/eval_later_result.hpp>
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#include <boost/metaparse/v1/error/none_of_the_expected_cases_found.hpp>
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#include <boost/mpl/eval_if.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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template <class... Ps>
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struct one_of;
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template <class P, class... Ps>
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struct one_of<P, Ps...>
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{
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typedef one_of 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<typename P::template apply<S, Pos>>::type,
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boost::mpl::eval_if<
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typename is_error<
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typename one_of<Ps...>::template apply<S, Pos>
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>::type,
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impl::eval_later_result<
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typename P::template apply<S, Pos>,
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typename one_of<Ps...>::template apply<S, Pos>
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>,
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typename one_of<Ps...>::template apply<S, Pos>
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>,
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typename P::template apply<S, Pos>
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>
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{};
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};
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template <>
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struct one_of<> : fail<error::none_of_the_expected_cases_found> {};
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}
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}
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}
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#endif
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