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 // UNSUPPORTED: c++03, c++11, c++14, c++17
11
12 // <future>
13
14 // template <class F, class... Args>
15 // future<typename result_of<F(Args...)>::type>
16 // async(F&& f, Args&&... args);
17
18 // template <class F, class... Args>
19 // future<typename result_of<F(Args...)>::type>
20 // async(launch policy, F&& f, Args&&... args);
21
22
23 #include <future>
24
foo(int x)25 int foo (int x) { return x; }
26
f()27 void f() {
28 std::async( foo, 3); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
29 std::async(std::launch::async, foo, 3); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
30 }
31