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