1 // Copyright (C) 2014 Vicente Botet 2 // 3 // Distributed under the Boost Software License, Version 1.0. (See accompanying 4 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) 5 6 #define BOOST_THREAD_PROVIDES_FUTURE 7 #define BOOST_THREAD_PROVIDES_FUTURE_CONTINUATION 8 #include <boost/config.hpp> 9 #if ! defined BOOST_NO_CXX11_DECLTYPE 10 #define BOOST_RESULT_OF_USE_DECLTYPE 11 #endif 12 13 #include <boost/thread/future.hpp> 14 15 main()16int main() 17 { 18 #if ! defined BOOST_NO_CXX11_LAMBDAS && ! (defined BOOST_MSVC && _MSC_VER < 1700) 19 boost::promise<int> prom; 20 boost::future<int> futr = prom.get_future(); 21 22 int callCount = 0; 23 24 boost::future<void> futr2 = futr.then(boost::launch::deferred, 25 [&] (boost::future<int> f) { 26 callCount++; 27 assert(f.valid()); 28 assert(f.is_ready()); 29 assert(17 == f.get()); 30 }); 31 32 assert(futr2.valid()); 33 assert(!futr2.is_ready()); 34 assert(0 == callCount); 35 36 prom.set_value(17); 37 assert(0 == callCount); 38 39 futr2.get(); 40 assert(1 == callCount); 41 42 #endif 43 return 0; 44 } 45