1 //===----------------------------------------------------------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is dual licensed under the MIT and the University of Illinois Open
6 // Source Licenses. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // UNSUPPORTED: libcpp-has-no-threads
11 // UNSUPPORTED: c++98, c++03, c++11, c++14, c++17
12 // UNSUPPORTED: clang-3.3, clang-3.4, clang-3.5, clang-3.6, clang-3.7, clang-3.8
13
14 // <future>
15
16 // template <class F, class... Args>
17 // future<typename result_of<F(Args...)>::type>
18 // async(F&& f, Args&&... args);
19
20 // template <class F, class... Args>
21 // future<typename result_of<F(Args...)>::type>
22 // async(launch policy, F&& f, Args&&... args);
23
24
25 #include <future>
26 #include <atomic>
27 #include <memory>
28 #include <cassert>
29
30 #include "test_macros.h"
31
foo(int x)32 int foo (int x) { return x; }
33
main()34 int main ()
35 {
36 std::async( foo, 3); // expected-error {{ignoring return value of function declared with 'nodiscard' attribute}}
37 std::async(std::launch::async, foo, 3); // expected-error {{ignoring return value of function declared with 'nodiscard' attribute}}
38 }
39