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//===----------------------------------------------------------------------===//
// 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++03, c++11, c++14, c++17, c++20
// constexpr const T& operator*() const & noexcept;
// constexpr T& operator*() & noexcept;
// constexpr T&& operator*() && noexcept;
// constexpr const T&& operator*() const && noexcept;
#include <cassert>
#include <concepts>
#include <expected>
#include <type_traits>
#include <utility>
#include "test_macros.h"
// Test noexcept
template <class T>
concept DerefNoexcept =
requires(T t) {
{ std::forward<T>(t).operator*() } noexcept;
};
static_assert(!DerefNoexcept<int>);
static_assert(DerefNoexcept<std::expected<int, int>&>);
static_assert(DerefNoexcept<const std::expected<int, int>&>);
static_assert(DerefNoexcept<std::expected<int, int>&&>);
static_assert(DerefNoexcept<const std::expected<int, int>&&>);
constexpr bool test() {
// non-const &
{
std::expected<int, int> e(5);
decltype(auto) x = *e;
static_assert(std::same_as<decltype(x), int&>);
assert(&x == &(e.value()));
assert(x == 5);
}
// const &
{
const std::expected<int, int> e(5);
decltype(auto) x = *e;
static_assert(std::same_as<decltype(x), const int&>);
assert(&x == &(e.value()));
assert(x == 5);
}
// non-const &&
{
std::expected<int, int> e(5);
decltype(auto) x = *std::move(e);
static_assert(std::same_as<decltype(x), int&&>);
assert(&x == &(e.value()));
assert(x == 5);
}
// const &&
{
const std::expected<int, int> e(5);
decltype(auto) x = *std::move(e);
static_assert(std::same_as<decltype(x), const int&&>);
assert(&x == &(e.value()));
assert(x == 5);
}
return true;
}
int main(int, char**) {
test();
static_assert(test());
return 0;
}
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