| 1 | // Copyright Louis Dionne 2013-2022 |
|---|---|
| 2 | // Distributed under the Boost Software License, Version 1.0. |
| 3 | // (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt) |
| 4 | |
| 5 | #include <boost/hana/ext/std/pair.hpp> |
| 6 | #include <boost/hana/first.hpp> |
| 7 | #include <boost/hana/second.hpp> |
| 8 | |
| 9 | #include <utility> |
| 10 | namespace hana = boost::hana; |
| 11 | |
| 12 | |
| 13 | template <typename T> |
| 14 | T const& cref(T& t) { return t; } |
| 15 | |
| 16 | // a non-movable, non-copyable type |
| 17 | template <int i> |
| 18 | struct RefOnly { |
| 19 | RefOnly() = default; |
| 20 | RefOnly(RefOnly const&) = delete; |
| 21 | RefOnly(RefOnly&&) = delete; |
| 22 | }; |
| 23 | |
| 24 | int main() { |
| 25 | // This test makes sure that we return the proper reference types from |
| 26 | // `first` and `second`. |
| 27 | std::pair<RefOnly<0>, RefOnly<1>> p; |
| 28 | |
| 29 | { |
| 30 | RefOnly<0>&& r1 = hana::first(std::move(p)); |
| 31 | RefOnly<0>& r2 = hana::first(p); |
| 32 | RefOnly<0> const& r3 = hana::first(cref(t&: p)); |
| 33 | |
| 34 | (void)r1; (void)r2; (void)r3; |
| 35 | } |
| 36 | |
| 37 | { |
| 38 | RefOnly<1>&& r1 = hana::second(std::move(p)); |
| 39 | RefOnly<1>& r2 = hana::second(p); |
| 40 | RefOnly<1> const& r3 = hana::second(cref(t&: p)); |
| 41 | |
| 42 | (void)r1; (void)r2; (void)r3; |
| 43 | } |
| 44 | } |
| 45 |