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 // UNSUPPORTED: c++03, c++11, c++14
10
11 // <utility>
12
13 // struct in_place_t {
14 // explicit in_place_t() = default;
15 // };
16 // inline constexpr in_place_t in_place{};
17
18 // template <class T>
19 // struct in_place_type_t {
20 // explicit in_place_type_t() = default;
21 // };
22 // template <class T>
23 // inline constexpr in_place_type_t<T> in_place_type{};
24
25 // template <size_t I>
26 // struct in_place_index_t {
27 // explicit in_place_index_t() = default;
28 // };
29 // template <size_t I>
30 // inline constexpr in_place_index_t<I> in_place_index{};
31
32 #include <cassert>
33 #include <memory>
34 #include <type_traits>
35 #include <utility>
36
37 template <class Tp, class Up>
check_tag(Up)38 constexpr bool check_tag(Up) {
39 return std::is_same<Tp, std::decay_t<Tp>>::value
40 && std::is_same<Tp, Up>::value;
41 }
42
main(int,char **)43 int main(int, char**) {
44 // test in_place_t
45 {
46 using T = std::in_place_t;
47 static_assert(check_tag<T>(std::in_place));
48 }
49 // test in_place_type_t
50 {
51 using T1 = std::in_place_type_t<void>;
52 using T2 = std::in_place_type_t<int>;
53 using T3 = std::in_place_type_t<const int>;
54 static_assert(!std::is_same<T1, T2>::value && !std::is_same<T1, T3>::value);
55 static_assert(!std::is_same<T2, T3>::value);
56 static_assert(check_tag<T1>(std::in_place_type<void>));
57 static_assert(check_tag<T2>(std::in_place_type<int>));
58 static_assert(check_tag<T3>(std::in_place_type<const int>));
59 }
60 // test in_place_index_t
61 {
62 using T1 = std::in_place_index_t<0>;
63 using T2 = std::in_place_index_t<1>;
64 using T3 = std::in_place_index_t<static_cast<std::size_t>(-1)>;
65 static_assert(!std::is_same<T1, T2>::value && !std::is_same<T1, T3>::value);
66 static_assert(!std::is_same<T2, T3>::value);
67 static_assert(check_tag<T1>(std::in_place_index<0>));
68 static_assert(check_tag<T2>(std::in_place_index<1>));
69 static_assert(check_tag<T3>(std::in_place_index<static_cast<std::size_t>(-1)>));
70 }
71
72 return 0;
73 }
74