xref: /llvm-project/libcxx/test/std/thread/futures/futures.future_error/what.pass.cpp (revision 3497500946c9b6a1b2e1452312a24c41ee412b34)
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 
main(int,char **)28 int 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