1 //===----------------------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 // <tuple>
10 
11 // template <class... Types> class tuple;
12 
13 // template <size_t I, class... Types>
14 //   typename tuple_element<I, tuple<Types...> >::type const&
15 //   get(const tuple<Types...>& t);
16 
17 // UNSUPPORTED: c++03
18 
19 #include <tuple>
20 #include <string>
21 #include <cassert>
22 
23 #include "test_macros.h"
24 
25 struct Empty {};
26 
27 int main(int, char**)
28 {
29     {
30         typedef std::tuple<int> T;
31         const T t(3);
32         assert(std::get<0>(t) == 3);
33     }
34     {
35         typedef std::tuple<std::string, int> T;
36         const T t("high", 5);
37         assert(std::get<0>(t) == "high");
38         assert(std::get<1>(t) == 5);
39     }
40 #if TEST_STD_VER > 11
41     {
42         typedef std::tuple<double, int> T;
43         constexpr T t(2.718, 5);
44         static_assert(std::get<0>(t) == 2.718, "");
45         static_assert(std::get<1>(t) == 5, "");
46     }
47     {
48         typedef std::tuple<Empty> T;
49         constexpr T t{Empty()};
50         constexpr Empty e = std::get<0>(t);
51         ((void)e); // Prevent unused warning
52     }
53 #endif
54     {
55         typedef std::tuple<double&, std::string, int> T;
56         double d = 1.5;
57         const T t(d, "high", 5);
58         assert(std::get<0>(t) == 1.5);
59         assert(std::get<1>(t) == "high");
60         assert(std::get<2>(t) == 5);
61         std::get<0>(t) = 2.5;
62         assert(std::get<0>(t) == 2.5);
63         assert(std::get<1>(t) == "high");
64         assert(std::get<2>(t) == 5);
65         assert(d == 2.5);
66     }
67 
68   return 0;
69 }
70