xref: /llvm-project/libcxx/test/std/thread/futures/futures.promise/set_lvalue.pass.cpp (revision a7f9895cc18995549c7facb96e72718da282a864)
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
11 
12 // <future>
13 
14 // class promise<R>
15 
16 // void promise<R&>::set_value(R& r);
17 
18 #include <future>
19 #include <cassert>
20 
21 #include "test_macros.h"
22 
main(int,char **)23 int main(int, char**)
24 {
25     {
26         typedef int& T;
27         int i = 3;
28         std::promise<T> p;
29         std::future<T> f = p.get_future();
30         p.set_value(i);
31         int& j = f.get();
32         assert(j == 3);
33         ++i;
34         assert(j == 4);
35 #ifndef TEST_HAS_NO_EXCEPTIONS
36         try
37         {
38             p.set_value(i);
39             assert(false);
40         }
41         catch (const std::future_error& e)
42         {
43             assert(e.code() == make_error_code(std::future_errc::promise_already_satisfied));
44         }
45 #endif
46     }
47 
48   return 0;
49 }
50