45 lines
1.1 KiB
C++
45 lines
1.1 KiB
C++
// Copyright Louis Dionne 2013-2017
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// Distributed under the Boost Software License, Version 1.0.
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// (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
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#include <boost/hana/ext/std/pair.hpp>
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#include <boost/hana/first.hpp>
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#include <boost/hana/second.hpp>
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#include <utility>
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namespace hana = boost::hana;
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template <typename T>
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T const& cref(T& t) { return t; }
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// a non-movable, non-copyable type
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template <int i>
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struct RefOnly {
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RefOnly() = default;
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RefOnly(RefOnly const&) = delete;
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RefOnly(RefOnly&&) = delete;
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};
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int main() {
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// This test makes sure that we return the proper reference types from
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// `first` and `second`.
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std::pair<RefOnly<0>, RefOnly<1>> p;
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{
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RefOnly<0>&& r1 = hana::first(std::move(p));
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RefOnly<0>& r2 = hana::first(p);
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RefOnly<0> const& r3 = hana::first(cref(p));
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(void)r1; (void)r2; (void)r3;
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}
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{
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RefOnly<1>&& r1 = hana::second(std::move(p));
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RefOnly<1>& r2 = hana::second(p);
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RefOnly<1> const& r3 = hana::second(cref(p));
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(void)r1; (void)r2; (void)r3;
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}
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}
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