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 explicit operator bool() const noexcept; 12 13 #include <cassert> 14 #include <concepts> 15 #include <expected> 16 #include <type_traits> 17 #include <utility> 18 19 #include "test_macros.h" 20 21 // Test noexcept 22 template <class T> 23 concept OpBoolNoexcept = 24 requires(T t) { 25 { static_cast<bool>(t) } noexcept; 26 }; 27 28 struct Foo {}; 29 static_assert(!OpBoolNoexcept<Foo>); 30 31 static_assert(OpBoolNoexcept<std::expected<int, int>>); 32 static_assert(OpBoolNoexcept<const std::expected<int, int>>); 33 34 // Test explicit 35 static_assert(!std::is_convertible_v<std::expected<int, int>, bool>); 36 37 constexpr bool test() { 38 // has_value 39 { 40 const std::expected<int, int> e(5); 41 assert(static_cast<bool>(e)); 42 } 43 44 // !has_value 45 { 46 const std::expected<int, int> e(std::unexpect, 5); 47 assert(!static_cast<bool>(e)); 48 } 49 50 return true; 51 } 52 53 int main(int, char**) { 54 test(); 55 static_assert(test()); 56 return 0; 57 } 58