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: no-threads
10
11// VC Runtime's std::exception::what() method is not marked as noexcept, so
12// this fails.
13// UNSUPPORTED: target=x86_64-pc-windows-msvc
14
15// <future>
16//
17// class future_error
18//
19// const char* what() const noexcept;
20
21#include <cassert>
22#include <future>
23#include <string_view>
24#include <utility>
25
26#include "test_macros.h"
27
28int main(int, char**) {
29 ASSERT_NOEXCEPT(std::declval<std::future_error const&>().what());
30 ASSERT_SAME_TYPE(decltype(std::declval<std::future_error const&>().what()), char const*);
31
32 // Before C++17, we can't construct std::future_error directly in a standards-conforming way
33#if TEST_STD_VER >= 17
34 {
35 std::future_error const f(std::future_errc::broken_promise);
36 [[maybe_unused]] char const* what = f.what();
37 LIBCPP_ASSERT(what == std::string_view{"The associated promise has been destructed prior "
38 "to the associated state becoming ready."});
39 }
40 {
41 std::future_error f(std::future_errc::future_already_retrieved);
42 [[maybe_unused]] char const* what = f.what();
43 LIBCPP_ASSERT(what == std::string_view{"The future has already been retrieved from "
44 "the promise or packaged_task."});
45 }
46 {
47 std::future_error f(std::future_errc::promise_already_satisfied);
48 [[maybe_unused]] char const* what = f.what();
49 LIBCPP_ASSERT(what == std::string_view{"The state of the promise has already been set."});
50 }
51 {
52 std::future_error f(std::future_errc::no_state);
53 [[maybe_unused]] char const* what = f.what();
54 LIBCPP_ASSERT(what == std::string_view{"Operation not permitted on an object without "
55 "an associated state."});
56 }
57#endif
58
59 return 0;
60}
61

source code of libcxx/test/std/thread/futures/futures.future_error/what.pass.cpp