67 lines · cpp
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-exception6//7//===----------------------------------------------------------------------===//8 9// UNSUPPORTED: c++03, c++11, c++1410 11// <optional>12 13// constexpr const T& optional<T>::value() const &;14 15#include <optional>16#include <type_traits>17#include <cassert>18 19#include "test_macros.h"20 21using std::optional;22using std::in_place_t;23using std::in_place;24using std::bad_optional_access;25 26struct X27{28 X() = default;29 X(const X&) = delete;30 constexpr int test() const & {return 3;}31 int test() & {return 4;}32 constexpr int test() const && {return 5;}33 int test() && {return 6;}34};35 36int main(int, char**)37{38 {39 const optional<X> opt; ((void)opt);40 ASSERT_NOT_NOEXCEPT(opt.value());41 ASSERT_SAME_TYPE(decltype(opt.value()), X const&);42 }43 {44 constexpr optional<X> opt(in_place);45 static_assert(opt.value().test() == 3, "");46 }47 {48 const optional<X> opt(in_place);49 assert(opt.value().test() == 3);50 }51#ifndef TEST_HAS_NO_EXCEPTIONS52 {53 const optional<X> opt;54 try55 {56 (void)opt.value();57 assert(false);58 }59 catch (const bad_optional_access&)60 {61 }62 }63#endif64 65 return 0;66}67