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 // constexpr tuple();
15 
16 #include <tuple>
17 #include <string>
18 #include <cassert>
19 #include <type_traits>
20 
21 #include "DefaultOnly.h"
22 
23 struct NoDefault {
24     NoDefault() = delete;
25     explicit NoDefault(int) { }
26 };
27 
28 struct NoExceptDefault {
29     NoExceptDefault() noexcept = default;
30 };
31 
32 struct ThrowingDefault {
33     ThrowingDefault() { }
34 };
35 
36 int main()
37 {
38     {
39         std::tuple<> t;
40     }
41     {
42         std::tuple<int> t;
43         assert(std::get<0>(t) == 0);
44     }
45     {
46         std::tuple<int, char*> t;
47         assert(std::get<0>(t) == 0);
48         assert(std::get<1>(t) == nullptr);
49     }
50     {
51         std::tuple<int, char*, std::string> t;
52         assert(std::get<0>(t) == 0);
53         assert(std::get<1>(t) == nullptr);
54         assert(std::get<2>(t) == "");
55     }
56     {
57         std::tuple<int, char*, std::string, DefaultOnly> t;
58         assert(std::get<0>(t) == 0);
59         assert(std::get<1>(t) == nullptr);
60         assert(std::get<2>(t) == "");
61         assert(std::get<3>(t) == DefaultOnly());
62     }
63     {
64         // See bug #21157.
65         static_assert(!std::is_default_constructible<std::tuple<NoDefault>>(), "");
66         static_assert(!std::is_default_constructible<std::tuple<DefaultOnly, NoDefault>>(), "");
67         static_assert(!std::is_default_constructible<std::tuple<NoDefault, DefaultOnly, NoDefault>>(), "");
68     }
69     {
70         static_assert(noexcept(std::tuple<NoExceptDefault>()), "");
71         static_assert(noexcept(std::tuple<NoExceptDefault, NoExceptDefault>()), "");
72 
73         static_assert(!noexcept(std::tuple<ThrowingDefault, NoExceptDefault>()), "");
74         static_assert(!noexcept(std::tuple<NoExceptDefault, ThrowingDefault>()), "");
75         static_assert(!noexcept(std::tuple<ThrowingDefault, ThrowingDefault>()), "");
76     }
77 #ifndef _LIBCPP_HAS_NO_CONSTEXPR
78     {
79         constexpr std::tuple<> t;
80     }
81     {
82         constexpr std::tuple<int> t;
83         assert(std::get<0>(t) == 0);
84     }
85     {
86         constexpr std::tuple<int, char*> t;
87         assert(std::get<0>(t) == 0);
88         assert(std::get<1>(t) == nullptr);
89     }
90 #endif
91 }
92