async.fail.cpp
1.24 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// UNSUPPORTED: libcpp-has-no-threads
// UNSUPPORTED: c++98, c++03, c++11, c++14, c++17
// UNSUPPORTED: clang-3.3, clang-3.4, clang-3.5, clang-3.6, clang-3.7, clang-3.8
// <future>
// template <class F, class... Args>
// future<typename result_of<F(Args...)>::type>
// async(F&& f, Args&&... args);
// template <class F, class... Args>
// future<typename result_of<F(Args...)>::type>
// async(launch policy, F&& f, Args&&... args);
#include <future>
#include <atomic>
#include <memory>
#include <cassert>
#include "test_macros.h"
int foo (int x) { return x; }
int main(int, char**)
{
std::async( foo, 3); // expected-error {{ignoring return value of function declared with 'nodiscard' attribute}}
std::async(std::launch::async, foo, 3); // expected-error {{ignoring return value of function declared with 'nodiscard' attribute}}
return 0;
}