{ return (int(__policy) & int(__value)) != 0; }
template <class _Fp, class... _Args>
+_LIBCPP_NODISCARD_AFTER_CXX17
future<typename __invoke_of<typename decay<_Fp>::type, typename decay<_Args>::type...>::type>
async(launch __policy, _Fp&& __f, _Args&&... __args)
{
}
template <class _Fp, class... _Args>
-inline _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_NODISCARD_AFTER_CXX17 inline _LIBCPP_INLINE_VISIBILITY
future<typename __invoke_of<typename decay<_Fp>::type, typename decay<_Args>::type...>::type>
async(_Fp&& __f, _Args&&... __args)
{
--- /dev/null
+//===----------------------------------------------------------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// UNSUPPORTED: libcpp-has-no-threads
+// UNSUPPORTED: c++98, c++03
+
+// <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 ()
+{
+ 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}}
+}
\ No newline at end of file