52 lines
1.5 KiB
C++
52 lines
1.5 KiB
C++
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// Copyright 2019 Peter Dimov.
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//
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// Distributed under the Boost Software License, Version 1.0.
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//
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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/mp11/utility.hpp>
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#include <boost/core/lightweight_test_trait.hpp>
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#include <cstddef>
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template<class T> using difference_type = typename T::difference_type;
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struct X
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{
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};
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struct Y
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{
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using difference_type = int;
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};
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int main()
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{
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using boost::mp11::mp_eval_or;
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using boost::mp11::mp_eval_or_q;
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using boost::mp11::mp_identity;
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using boost::mp11::mp_quote;
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BOOST_TEST_TRAIT_SAME(mp_eval_or<void, mp_identity>, void);
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BOOST_TEST_TRAIT_SAME(mp_eval_or<void, mp_identity, int>, mp_identity<int>);
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BOOST_TEST_TRAIT_SAME(mp_eval_or<void, mp_identity, int, int>, void);
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using Q_identity = mp_quote<mp_identity>;
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BOOST_TEST_TRAIT_SAME(mp_eval_or_q<void, Q_identity>, void);
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BOOST_TEST_TRAIT_SAME(mp_eval_or_q<void, Q_identity, int>, mp_identity<int>);
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BOOST_TEST_TRAIT_SAME(mp_eval_or_q<void, Q_identity, int, int>, void);
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BOOST_TEST_TRAIT_SAME(mp_eval_or<std::ptrdiff_t, difference_type, X>, std::ptrdiff_t);
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BOOST_TEST_TRAIT_SAME(mp_eval_or<std::ptrdiff_t, difference_type, Y>, int);
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using Q_diff_type = mp_quote<difference_type>;
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BOOST_TEST_TRAIT_SAME(mp_eval_or_q<std::ptrdiff_t, Q_diff_type, X>, std::ptrdiff_t);
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BOOST_TEST_TRAIT_SAME(mp_eval_or_q<std::ptrdiff_t, Q_diff_type, Y>, int);
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return boost::report_errors();
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}
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