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 12 // <future> 13 14 // class promise<R> 15 16 // void promise<R&>::set_value(R& r); 17 18 #include <future> 19 #include <cassert> 20 main()21int main() 22 { 23 { 24 typedef int& T; 25 int i = 3; 26 std::promise<T> p; 27 std::future<T> f = p.get_future(); 28 p.set_value(i); 29 int& j = f.get(); 30 assert(j == 3); 31 ++i; 32 assert(j == 4); 33 try 34 { 35 p.set_value(i); 36 assert(false); 37 } 38 catch (const std::future_error& e) 39 { 40 assert(e.code() == make_error_code(std::future_errc::promise_already_satisfied)); 41 } 42 } 43 } 44