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 10 11 // <system_error> 12 13 // template <class T> constexpr bool is_error_condition_enum_v; 14 15 #include <system_error> 16 #include <type_traits> 17 #include "test_macros.h" 18 19 template <bool Expected, class T> 20 void 21 test() 22 { 23 static_assert((std::is_error_condition_enum<T>::value == Expected), ""); 24 #if TEST_STD_VER > 14 25 static_assert((std::is_error_condition_enum_v<T> == Expected), ""); 26 ASSERT_SAME_TYPE(decltype(std::is_error_condition_enum_v<T>), const bool); 27 #endif 28 } 29 30 class A { 31 A(); 32 operator std::error_condition () const { return std::error_condition(); } 33 }; 34 35 // Specialize the template for my class 36 namespace std 37 { 38 template <> 39 struct is_error_condition_enum<A> : public std::true_type {}; 40 } 41 42 43 int main(int, char**) 44 { 45 test<false, void>(); 46 test<false, int>(); 47 test<false, std::nullptr_t>(); 48 test<false, std::string>(); 49 50 test<true, A>(); 51 52 return 0; 53 } 54