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/tuple.hpp>
7 
8 #include <string>
9 namespace hana = boost::hana;
10 
11 
12 struct Empty {};
13 
14 struct S {
SS15     constexpr S()
16         : a{1, Empty{}},
17           k(hana::at_c<0>(a)),
18           e(hana::at_c<1>(a))
19     { }
20 
21     hana::tuple<int, Empty> a;
22     int k;
23     Empty e;
24 };
25 
getP()26 constexpr hana::tuple<int, int> getP () { return { 3, 4 }; }
27 
main()28 int main() {
29     {
30         using T = hana::tuple<int>;
31         T t(3);
32         BOOST_HANA_RUNTIME_CHECK(hana::at_c<0>(t) == 3);
33         hana::at_c<0>(t) = 2;
34         BOOST_HANA_RUNTIME_CHECK(hana::at_c<0>(t) == 2);
35     }
36     {
37         using T = hana::tuple<std::string, int>;
38         T t("high", 5);
39         BOOST_HANA_RUNTIME_CHECK(hana::at_c<0>(t) == "high");
40         BOOST_HANA_RUNTIME_CHECK(hana::at_c<1>(t) == 5);
41         hana::at_c<0>(t) = "four";
42         hana::at_c<1>(t) = 4;
43         BOOST_HANA_RUNTIME_CHECK(hana::at_c<0>(t) == "four");
44         BOOST_HANA_RUNTIME_CHECK(hana::at_c<1>(t) == 4);
45     }
46     {
47         using T = hana::tuple<double&, std::string, int>;
48         double d = 1.5;
49         T t(d, "high", 5);
50         BOOST_HANA_RUNTIME_CHECK(hana::at_c<0>(t) == 1.5);
51         BOOST_HANA_RUNTIME_CHECK(hana::at_c<1>(t) == "high");
52         BOOST_HANA_RUNTIME_CHECK(hana::at_c<2>(t) == 5);
53         hana::at_c<0>(t) = 2.5;
54         hana::at_c<1>(t) = "four";
55         hana::at_c<2>(t) = 4;
56         BOOST_HANA_RUNTIME_CHECK(hana::at_c<0>(t) == 2.5);
57         BOOST_HANA_RUNTIME_CHECK(hana::at_c<1>(t) == "four");
58         BOOST_HANA_RUNTIME_CHECK(hana::at_c<2>(t) == 4);
59         BOOST_HANA_RUNTIME_CHECK(d == 2.5);
60     }
61     // get on a rvalue tuple
62     {
63         static_assert(hana::at_c<0>(hana::tuple<float, int, double, long>{0.0f, 1, 2.0, 3L}) == 0, "" );
64         static_assert(hana::at_c<1>(hana::tuple<float, int, double, long>{0.0f, 1, 2.0, 3L}) == 1, "" );
65         static_assert(hana::at_c<2>(hana::tuple<float, int, double, long>{0.0f, 1, 2.0, 3L}) == 2, "" );
66         static_assert(hana::at_c<3>(hana::tuple<float, int, double, long>{0.0f, 1, 2.0, 3L}) == 3, "" );
67         static_assert(S().k == 1, "");
68         static_assert(hana::at_c<1>(getP()) == 4, "");
69     }
70     {
71         // make sure get<> returns the right types
72         struct T { };
73         struct U { };
74         struct V { };
75 
76         hana::tuple<T, U, V> xs{};
77         (void)static_cast<T>(hana::at_c<0>(xs));
78         (void)static_cast<U>(hana::at_c<1>(xs));
79         (void)static_cast<V>(hana::at_c<2>(xs));
80     }
81 }
82