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 nullopt_t{see below};
13// constexpr nullopt_t nullopt(unspecified);
14
15#include <experimental/optional>
16#include <type_traits>
17
18#if _LIBCPP_STD_VER > 11
19
20using std::experimental::optional;
21using std::experimental::nullopt_t;
22using std::experimental::nullopt;
23
24constexpr
25int
26test(const nullopt_t&)
27{
28    return 3;
29}
30
31#endif
32
33int main()
34{
35#if _LIBCPP_STD_VER > 11
36    static_assert((std::is_class<nullopt_t>::value), "");
37    static_assert((std::is_empty<nullopt_t>::value), "");
38    static_assert((std::is_literal_type<nullopt_t>::value), "");
39    static_assert((!std::is_default_constructible<nullopt_t>::value), "");
40
41    static_assert(test(nullopt) == 3, "");
42#endif
43}
44