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 // constexpr bool optional<T>::has_value() const noexcept;
14 
15 #include <optional>
16 #include <type_traits>
17 #include <cassert>
18 
19 #include "test_macros.h"
20 
main()21 int main()
22 {
23     using std::optional;
24     {
25         const optional<int> opt; ((void)opt);
26         ASSERT_NOEXCEPT(opt.has_value());
27         ASSERT_SAME_TYPE(decltype(opt.has_value()), bool);
28     }
29     {
30         constexpr optional<int> opt;
31         static_assert(!opt.has_value(), "");
32     }
33     {
34         constexpr optional<int> opt(0);
35         static_assert(opt.has_value(), "");
36     }
37 }
38