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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
// template<class... Args>
// constexpr explicit expected(unexpect_t, Args&&... args);
//
// Constraints: is_constructible_v<E, Args...> is true.
//
// Effects: Direct-non-list-initializes unex with std::forward<Args>(args)....
//
// Postconditions: has_value() is false.
//
// Throws: Any exception thrown by the initialization of unex.
#include <cassert>
#include <expected>
#include <tuple>
#include <type_traits>
#include <utility>
#include "MoveOnly.h"
#include "test_macros.h"
// Test Constraints:
static_assert(std::is_constructible_v<std::expected<int, int>, std::unexpect_t>);
static_assert(std::is_constructible_v<std::expected<int, int>, std::unexpect_t, int>);
// !is_constructible_v<T, Args...>
struct foo {};
static_assert(!std::is_constructible_v<std::expected<int, foo>, std::unexpect_t, int>);
// test explicit
template <class T>
void conversion_test(T);
template <class T, class... Args>
concept ImplicitlyConstructible = requires(Args&&... args) { conversion_test<T>({std::forward<Args>(args)...}); };
static_assert(ImplicitlyConstructible<int, int>);
static_assert(!ImplicitlyConstructible<std::expected<int, int>, std::unexpect_t>);
static_assert(!ImplicitlyConstructible<std::expected<int, int>, std::unexpect_t, int>);
struct CopyOnly {
int i;
constexpr CopyOnly(int ii) : i(ii) {}
CopyOnly(const CopyOnly&) = default;
CopyOnly(CopyOnly&&) = delete;
friend constexpr bool operator==(const CopyOnly& mi, int ii) { return mi.i == ii; }
};
template <class T>
constexpr void testInt() {
std::expected<int, T> e(std::unexpect, 5);
assert(!e.has_value());
assert(e.error() == 5);
}
template <class T>
constexpr void testLValue() {
T t(5);
std::expected<int, T> e(std::unexpect, t);
assert(!e.has_value());
assert(e.error() == 5);
}
template <class T>
constexpr void testRValue() {
std::expected<int, T> e(std::unexpect, T(5));
assert(!e.has_value());
assert(e.error() == 5);
}
constexpr bool test() {
testInt<int>();
testInt<CopyOnly>();
testInt<MoveOnly>();
testLValue<int>();
testLValue<CopyOnly>();
testRValue<int>();
testRValue<MoveOnly>();
// no arg
{
std::expected<int, int> e(std::unexpect);
assert(!e.has_value());
assert(e.error() == 0);
}
// one arg
{
std::expected<int, int> e(std::unexpect, 5);
assert(!e.has_value());
assert(e.error() == 5);
}
// multi args
{
std::expected<int, std::tuple<int, short, MoveOnly>> e(std::unexpect, 1, short{2}, MoveOnly(3));
assert(!e.has_value());
assert((e.error() == std::tuple<int, short, MoveOnly>(1, short{2}, MoveOnly(3))));
}
return true;
}
void testException() {
#ifndef TEST_HAS_NO_EXCEPTIONS
struct Except {};
struct Throwing {
Throwing(int) { throw Except{}; };
};
try {
std::expected<int, Throwing> u(std::unexpect, 5);
assert(false);
} catch (Except) {
}
#endif // TEST_HAS_NO_EXCEPTIONS
}
int main(int, char**) {
test();
static_assert(test());
testException();
return 0;
}
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