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>
12 // tuple<Types&&...> forward_as_tuple(Types&&... t);
13
14 // UNSUPPORTED: c++03
15
16 #include <tuple>
17 #include <type_traits>
18 #include <cassert>
19
20 #include "test_macros.h"
21
22 template <class Tuple>
23 void
test0(const Tuple &)24 test0(const Tuple&)
25 {
26 static_assert(std::tuple_size<Tuple>::value == 0, "");
27 }
28
29 template <class Tuple>
30 void
test1a(const Tuple & t)31 test1a(const Tuple& t)
32 {
33 static_assert(std::tuple_size<Tuple>::value == 1, "");
34 static_assert(std::is_same<typename std::tuple_element<0, Tuple>::type, int&&>::value, "");
35 assert(std::get<0>(t) == 1);
36 }
37
38 template <class Tuple>
39 void
test1b(const Tuple & t)40 test1b(const Tuple& t)
41 {
42 static_assert(std::tuple_size<Tuple>::value == 1, "");
43 static_assert(std::is_same<typename std::tuple_element<0, Tuple>::type, int&>::value, "");
44 assert(std::get<0>(t) == 2);
45 }
46
47 template <class Tuple>
48 void
test2a(const Tuple & t)49 test2a(const Tuple& t)
50 {
51 static_assert(std::tuple_size<Tuple>::value == 2, "");
52 static_assert(std::is_same<typename std::tuple_element<0, Tuple>::type, double&>::value, "");
53 static_assert(std::is_same<typename std::tuple_element<1, Tuple>::type, char&>::value, "");
54 assert(std::get<0>(t) == 2.5);
55 assert(std::get<1>(t) == 'a');
56 }
57
58 #if TEST_STD_VER > 11
59 template <class Tuple>
60 constexpr int
test3(const Tuple &)61 test3(const Tuple&)
62 {
63 return std::tuple_size<Tuple>::value;
64 }
65 #endif
66
main(int,char **)67 int main(int, char**)
68 {
69 {
70 test0(std::forward_as_tuple());
71 }
72 {
73 test1a(std::forward_as_tuple(1));
74 }
75 {
76 int i = 2;
77 test1b(std::forward_as_tuple(i));
78 }
79 {
80 double i = 2.5;
81 char c = 'a';
82 test2a(std::forward_as_tuple(i, c));
83 #if TEST_STD_VER > 11
84 static_assert ( test3 (std::forward_as_tuple(i, c)) == 2, "" );
85 #endif
86 }
87
88 return 0;
89 }
90