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-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 // UNSUPPORTED: c++03, c++11, c++14, c++17, c++20 10 11 // constexpr ~expected(); 12 // 13 // Effects: If has_value() is true, destroys val, otherwise destroys unex. 14 // 15 // Remarks: If is_trivially_destructible_v<T> is true, and is_trivially_destructible_v<E> is true, 16 // then this destructor is a trivial destructor. 17 18 #include <cassert> 19 #include <expected> 20 #include <type_traits> 21 #include <utility> 22 #include <memory> 23 24 #include "test_macros.h" 25 26 // Test Remarks: If is_trivially_destructible_v<T> is true, and is_trivially_destructible_v<E> is true, 27 // then this destructor is a trivial destructor. 28 struct NonTrivial { 29 ~NonTrivial() {} 30 }; 31 32 static_assert(std::is_trivially_destructible_v<std::expected<int, int>>); 33 static_assert(!std::is_trivially_destructible_v<std::expected<NonTrivial, int>>); 34 static_assert(!std::is_trivially_destructible_v<std::expected<int, NonTrivial>>); 35 static_assert(!std::is_trivially_destructible_v<std::expected<NonTrivial, NonTrivial>>); 36 37 struct TrackedDestroy { 38 bool& destroyed; 39 constexpr TrackedDestroy(bool& b) : destroyed(b) {} 40 constexpr ~TrackedDestroy() { destroyed = true; } 41 }; 42 43 constexpr bool test() { 44 // has value 45 { 46 bool valueDestroyed = false; 47 { [[maybe_unused]] std::expected<TrackedDestroy, TrackedDestroy> e(std::in_place, valueDestroyed); } 48 assert(valueDestroyed); 49 } 50 51 // has error 52 { 53 bool errorDestroyed = false; 54 { [[maybe_unused]] std::expected<TrackedDestroy, TrackedDestroy> e(std::unexpect, errorDestroyed); } 55 assert(errorDestroyed); 56 } 57 58 return true; 59 } 60 61 int main(int, char**) { 62 std::expected<std::unique_ptr<int>, int> a = std::make_unique<int>(42); 63 64 test(); 65 static_assert(test()); 66 return 0; 67 } 68