1 // Copyright Louis Dionne 2013-2017
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/assert.hpp>
6 #include <boost/hana/equal.hpp>
7 #include <boost/hana/type.hpp>
8 
9 #include <type_traits>
10 namespace hana = boost::hana;
11 
12 
13 // This test checks that the unary + operator on types works as expected.
14 // The unary + operator is supposed to turn a reference to a hana::type
15 // object into an equivalent prvalue.
16 
17 struct T;
18 
main()19 int main() {
20     auto& ref = hana::type_c<T>;
21     auto const& cref = hana::type_c<T>;
22     auto&& rref = hana::type_c<T>;
23     auto val = hana::type_c<T>;
24 
25     BOOST_HANA_CONSTANT_CHECK(hana::equal(val, +val));
26     BOOST_HANA_CONSTANT_CHECK(hana::equal(val, +ref));
27     BOOST_HANA_CONSTANT_CHECK(hana::equal(val, +cref));
28     BOOST_HANA_CONSTANT_CHECK(hana::equal(val, +rref));
29 
30     static_assert(!std::is_reference<decltype(+val)>{}, "");
31     static_assert(!std::is_reference<decltype(+ref)>{}, "");
32     static_assert(!std::is_reference<decltype(+cref)>{}, "");
33     static_assert(!std::is_reference<decltype(+rref)>{}, "");
34 
35     using T1 = decltype(+val)::type;
36     using T2 = decltype(+ref)::type;
37     using T3 = decltype(+cref)::type;
38     using T4 = decltype(+rref)::type;
39 }
40