text: //===----------------------------------------------------------------------===//
  //
  //                     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.
  //
  //===----------------------------------------------------------------------===//
  
  // Copyright (C) 2011 Vicente J. Botet Escriba
  //
  //  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)
  
  // <future>
  
  // class promise<R>
  
  // promise& operator=(promise&& rhs);
  
  #define BOOST_THREAD_VERSION 4
  #if BOOST_THREAD_VERSION == 4
  #define BOOST_THREAD_DETAIL_SIGNATURE double()
  #else
  #define BOOST_THREAD_DETAIL_SIGNATURE double
  #endif
  
  #include <boost/thread/future.hpp>
  #include <boost/detail/lightweight_test.hpp>
  
  class A
  {
      long data_;
  
  public:
      explicit A(long i) : data_(i) {}
  
      long operator()() const {return data_;}
      long operator()(long i, long j) const {return data_ + i + j;}
  };
  
  
  int main()
  {
  
    {
        boost::packaged_task<BOOST_THREAD_DETAIL_SIGNATURE> p0(A(5));
        boost::packaged_task<BOOST_THREAD_DETAIL_SIGNATURE> p;
        p = boost::move(p0);
        BOOST_TEST(!p0.valid());
        BOOST_TEST(p.valid());
        boost::future<double> f = BOOST_THREAD_MAKE_RV_REF(p.get_future());
        // p(3, 'a');
        p();
        BOOST_TEST(f.get() == 5.0);
    }
    {
        boost::packaged_task<BOOST_THREAD_DETAIL_SIGNATURE> p0;
        boost::packaged_task<BOOST_THREAD_DETAIL_SIGNATURE> p;
        p = boost::move(p0);
        BOOST_TEST(!p0.valid());
        BOOST_TEST(!p.valid());
    }
  
    return boost::report_errors();
  
  }
  