third_party/boost/thread/example/lambda_future.cpp

// Copyright (C) 2013 Vicente Botet
//
//  Distributed under the Boost Software License, Version 1.0. (See accompanying
//  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)


#include <boost/config.hpp>
#if ! defined  BOOST_NO_CXX11_DECLTYPE
#define BOOST_RESULT_OF_USE_DECLTYPE
#endif

#define BOOST_THREAD_VERSION 4
//#define BOOST_THREAD_USES_LOG
#define BOOST_THREAD_USES_LOG_THREAD_ID

#include <boost/thread/detail/log.hpp>
#include <boost/thread/future.hpp>
#include <boost/assert.hpp>
#include <string>
#include <iostream>

#if    defined BOOST_THREAD_PROVIDES_FUTURE_CONTINUATION \
  && ! defined BOOST_NO_CXX11_LAMBDAS && ! (defined BOOST_MSVC && _MSC_VER < 1800) // works since msvc-12.0

#ifdef BOOST_MSVC
#pragma warning(disable: 4127) // conditional expression is constant
#endif

int main()
{
  const int number_of_tests = 100;
  BOOST_THREAD_LOG << "<MAIN" << BOOST_THREAD_END_LOG;

  for (int i=0; i< number_of_tests; i++)
  try
  {
    {
      boost::future<int> f1 = boost::async(boost::launch::async, []()  {return 123;});
      int result = f1.get();
      BOOST_THREAD_LOG << "f1 " << result << BOOST_THREAD_END_LOG;
    }
    {
      boost::future<int> f1 = boost::async(boost::launch::async, []() {return 123;});
      boost::future<int> f2 = f1.then([](boost::future<int> f)  {return 2*f.get(); });
      int result = f2.get();
      BOOST_THREAD_LOG << "f2 " << result << BOOST_THREAD_END_LOG;
    }
#if ! defined    BOOST_NO_CXX14_GENERIC_LAMBDAS
    {
      boost::future<int> f1 = boost::async(boost::launch::async, []() {return 123;});
      boost::future<int> f2 = f1.then([](auto f)  {return 2*f.get(); });
      int result = f2.get();
      BOOST_THREAD_LOG << "f2 " << result << BOOST_THREAD_END_LOG;
    }
#endif
  }
  catch (std::exception& ex)
  {
    std::cout << "ERRORRRRR "<<ex.what() << "" << std::endl;
    BOOST_THREAD_LOG << "ERRORRRRR "<<ex.what() << "" << BOOST_THREAD_END_LOG;
    return 1;
  }
  catch (...)
  {
    std::cout << " ERRORRRRR exception thrown" << std::endl;
    BOOST_THREAD_LOG << " ERRORRRRR exception thrown" << BOOST_THREAD_END_LOG;
    return 2;
  }
  BOOST_THREAD_LOG << "MAIN>" << BOOST_THREAD_END_LOG;
  return 0;
}
#else

//#warning "This test is not supported in this configuration, either because  Bosst.Thread has been configured to don't support continuations, the compiler doesn't provides lambdas or because they are buggy as for MSV versions < msvc-12.0"

int main()
{
  return 0;
}
#endif