nullopt_t.pass.cpp revision 0cdbe6048173c1f05628dbc85430acf191a3e173 
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 optional(nullopt_t) noexcept;
13
14#include <experimental/optional>
15#include <type_traits>
16#include <cassert>
17
18#if _LIBCPP_STD_VER > 11
19
20using std::experimental::optional;
21using std::experimental::nullopt_t;
22using std::experimental::nullopt;
23
24template <class Opt>
25void
26test_constexpr()
27{
28    static_assert(noexcept(Opt(nullopt)), "");
29    constexpr Opt opt(nullopt);
30    static_assert(static_cast<bool>(opt) == false, "");
31
32    struct test_constexpr_ctor
33        : public Opt
34    {
35        constexpr test_constexpr_ctor() {}
36    };
37}
38
39template <class Opt>
40void
41test()
42{
43    static_assert(noexcept(Opt(nullopt)), "");
44    Opt opt(nullopt);
45    assert(static_cast<bool>(opt) == false);
46
47    struct test_constexpr_ctor
48        : public Opt
49    {
50        constexpr test_constexpr_ctor() {}
51    };
52}
53
54struct X
55{
56    X();
57};
58
59#endif  // _LIBCPP_STD_VER > 11
60
61int main()
62{
63#if _LIBCPP_STD_VER > 11
64    test_constexpr<optional<int>>();
65    test_constexpr<optional<int*>>();
66    test<optional<X>>();
67#endif  // _LIBCPP_STD_VER > 11
68}
69