1 //===----------------------------------------------------------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is dual licensed under the MIT and the University of Illinois Open
6 // Source Licenses. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 // <tuple>
11 
12 // template <class... Types> class tuple;
13 
14 // template <size_t I, class... Types>
15 //   typename tuple_element<I, tuple<Types...> >::type const&
16 //   get(const tuple<Types...>& t);
17 
18 // UNSUPPORTED: c++98, c++03
19 
20 #include <tuple>
21 #include <string>
22 #include <cassert>
23 
24 struct Empty {};
25 
26 int main()
27 {
28     {
29         typedef std::tuple<int> T;
30         const T t(3);
31         assert(std::get<0>(t) == 3);
32     }
33     {
34         typedef std::tuple<std::string, int> T;
35         const T t("high", 5);
36         assert(std::get<0>(t) == "high");
37         assert(std::get<1>(t) == 5);
38     }
39 #if _LIBCPP_STD_VER > 11
40     {
41         typedef std::tuple<double, int> T;
42         constexpr T t(2.718, 5);
43         static_assert(std::get<0>(t) == 2.718, "");
44         static_assert(std::get<1>(t) == 5, "");
45     }
46     {
47         typedef std::tuple<Empty> T;
48         constexpr T t{Empty()};
49         constexpr Empty e = std::get<0>(t);
50         ((void)e); // Prevent unused warning
51     }
52 #endif
53     {
54         typedef std::tuple<double&, std::string, int> T;
55         double d = 1.5;
56         const T t(d, "high", 5);
57         assert(std::get<0>(t) == 1.5);
58         assert(std::get<1>(t) == "high");
59         assert(std::get<2>(t) == 5);
60         std::get<0>(t) = 2.5;
61         assert(std::get<0>(t) == 2.5);
62         assert(std::get<1>(t) == "high");
63         assert(std::get<2>(t) == 5);
64         assert(d == 2.5);
65     }
66 }
67