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 // UNSUPPORTED: c++98, c++03, c++11, c++14
11 // <optional>
12
13 // template <class T> constexpr bool operator==(const optional<T>& x, nullopt_t) noexcept;
14 // template <class T> constexpr bool operator==(nullopt_t, const optional<T>& x) noexcept;
15
16 #include <optional>
17
main()18 int main()
19 {
20 using std::optional;
21 using std::nullopt_t;
22 using std::nullopt;
23
24 {
25 typedef int T;
26 typedef optional<T> O;
27
28 constexpr O o1; // disengaged
29 constexpr O o2{1}; // engaged
30
31 static_assert ( (nullopt == o1), "" );
32 static_assert ( !(nullopt == o2), "" );
33 static_assert ( (o1 == nullopt), "" );
34 static_assert ( !(o2 == nullopt), "" );
35
36 static_assert (noexcept(nullopt == o1), "");
37 static_assert (noexcept(o1 == nullopt), "");
38 }
39 }
40