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 // <optional>
11
12 // template <class T> constexpr bool operator<(const optional<T>& x, nullopt_t) noexcept;
13 // template <class T> constexpr bool operator<(nullopt_t, const optional<T>& x) noexcept;
14
15 #include <optional>
16
17 #include "test_macros.h"
18
main(int,char **)19 int main(int, char**)
20 {
21 using std::optional;
22 using std::nullopt_t;
23 using std::nullopt;
24
25 {
26 typedef int T;
27 typedef optional<T> O;
28
29 constexpr O o1; // disengaged
30 constexpr O o2{1}; // engaged
31
32 static_assert ( !(nullopt < o1), "" );
33 static_assert ( (nullopt < o2), "" );
34 static_assert ( !(o1 < nullopt), "" );
35 static_assert ( !(o2 < nullopt), "" );
36
37 static_assert (noexcept(nullopt < o1), "");
38 static_assert (noexcept(o1 < nullopt), "");
39 }
40
41 return 0;
42 }
43