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 
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 <experimental/optional>
17 
18 #include "test_macros.h"
19 
main()20 int main()
21 {
22 #if TEST_STD_VER > 11
23     using std::experimental::optional;
24     using std::experimental::nullopt_t;
25     using std::experimental::nullopt;
26 
27     {
28     typedef int T;
29     typedef optional<T> O;
30 
31     constexpr O o1;     // disengaged
32     constexpr O o2{1};  // engaged
33 
34     static_assert (  (nullopt <= o1), "" );
35     static_assert (  (nullopt <= o2), "" );
36     static_assert (  (o1 <= nullopt), "" );
37     static_assert ( !(o2 <= nullopt), "" );
38 
39     static_assert (noexcept(nullopt <= o1), "");
40     static_assert (noexcept(o1 <= nullopt), "");
41     }
42 #endif
43 }
44