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// constexpr const T& optional<T>::value() const;
13
14#include <experimental/optional>
15#include <type_traits>
16#include <cassert>
17
18#if _LIBCPP_STD_VER > 11
19
20using std::experimental::optional;
21
22struct X
23{
24    constexpr int test() const {return 3;}
25    int test() {return 4;}
26};
27
28#endif  // _LIBCPP_STD_VER > 11
29
30int main()
31{
32#if _LIBCPP_STD_VER > 11
33    {
34        constexpr optional<X> opt;
35        static_assert(opt.value().test() == 3, "");
36    }
37#else
38#error
39#endif  // _LIBCPP_STD_VER > 11
40}
41