| //===----------------------------------------------------------------------===// |
| // 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<void, int>, std::unexpect_t>); |
| static_assert(std::is_constructible_v<std::expected<void, int>, std::unexpect_t, int>); |
| |
| // !is_constructible_v<T, Args...> |
| struct foo {}; |
| static_assert(!std::is_constructible_v<std::expected<void, 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<void, int>, std::unexpect_t>); |
| static_assert(!ImplicitlyConstructible<std::expected<void, 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<void, T> e(std::unexpect, 5); |
| assert(!e.has_value()); |
| assert(e.error() == 5); |
| } |
| |
| template <class T> |
| constexpr void testLValue() { |
| T t(5); |
| std::expected<void, T> e(std::unexpect, t); |
| assert(!e.has_value()); |
| assert(e.error() == 5); |
| } |
| |
| template <class T> |
| constexpr void testRValue() { |
| std::expected<void, 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<void, int> e(std::unexpect); |
| assert(!e.has_value()); |
| assert(e.error() == 0); |
| } |
| |
| // one arg |
| { |
| std::expected<void, int> e(std::unexpect, 5); |
| assert(!e.has_value()); |
| assert(e.error() == 5); |
| } |
| |
| // multi args |
| { |
| std::expected<void, 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<void, 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; |
| } |