libcxx/test/std/thread/futures/futures.future_error/what.pass.cpp

   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
  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 }