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 // <optional>
11 
12 // struct in_place_t{};
13 // constexpr in_place_t in_place{};
14 
15 #include <experimental/optional>
16 #include <type_traits>
17 
18 #if _LIBCPP_STD_VER > 11
19 
20 using std::experimental::optional;
21 using std::experimental::in_place_t;
22 using std::experimental::in_place;
23 
24 constexpr
25 int
test(const in_place_t &)26 test(const in_place_t&)
27 {
28     return 3;
29 }
30 
31 #endif
32 
main()33 int main()
34 {
35 #if _LIBCPP_STD_VER > 11
36 
37     static_assert((std::is_class<in_place_t>::value), "");
38     static_assert((std::is_empty<in_place_t>::value), "");
39 
40     static_assert(test(in_place) == 3, "");
41 #endif
42 }
43