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<class... Types>
14 //   tuple<Types&...> tie(Types&... t);
15 
16 // UNSUPPORTED: c++03
17 
18 #include <tuple>
19 #include <string>
20 #include <cassert>
21 
22 #include "test_macros.h"
23 
24 TEST_CONSTEXPR_CXX14
25 bool test_tie()
26 {
27     {
28         int i = 42;
29         double f = 1.1;
30         using ExpectT = std::tuple<int&, decltype(std::ignore)&, double&>;
31         auto res = std::tie(i, std::ignore, f);
32         static_assert(std::is_same<ExpectT, decltype(res)>::value, "");
33         assert(&std::get<0>(res) == &i);
34         assert(&std::get<1>(res) == &std::ignore);
35         assert(&std::get<2>(res) == &f);
36 
37 #if TEST_STD_VER >= 20
38         res = std::make_tuple(101, nullptr, -1.0);
39         assert(i == 101);
40         assert(f == -1.0);
41 #endif
42     }
43     return true;
44 }
45 
46 int main(int, char**)
47 {
48     test_tie();
49 #if TEST_STD_VER >= 14
50     static_assert(test_tie(), "");
51 #endif
52 
53     {
54         int i = 0;
55         std::string s;
56         std::tie(i, std::ignore, s) = std::make_tuple(42, 3.14, "C++");
57         assert(i == 42);
58         assert(s == "C++");
59     }
60 
61     return 0;
62 }
63