| //===----------------------------------------------------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| // UNSUPPORTED: c++98, c++03, c++11, c++14 |
| // <optional> |
| |
| // struct nullopt_t{see below}; |
| // inline constexpr nullopt_t nullopt(unspecified); |
| |
| // [optional.nullopt]/2: |
| // Type nullopt_t shall not have a default constructor or an initializer-list |
| // constructor, and shall not be an aggregate. |
| |
| #include <optional> |
| #include <type_traits> |
| |
| #include "test_macros.h" |
| |
| using std::nullopt_t; |
| using std::nullopt; |
| |
| constexpr bool test() |
| { |
| nullopt_t foo{nullopt}; |
| (void)foo; |
| return true; |
| } |
| |
| int main(int, char**) |
| { |
| static_assert(std::is_empty_v<nullopt_t>); |
| static_assert(!std::is_default_constructible_v<nullopt_t>); |
| |
| static_assert(std::is_same_v<const nullopt_t, decltype(nullopt)>); |
| static_assert(test()); |
| |
| return 0; |
| } |