title: How to use boost asio library with Cygwin 64 bit
body: <p>I am running Windows 10 64bit. Cygwin is 64 bit.</p>
  
  <p>I installed boost from cygwin package manager.</p>
  
  <p>I tried to compile test.cpp:</p>
  
  <pre><code>#include &lt;boost/asio.hpp&gt;
  int
  main(int argc, char**argv)
  {
      return 0;
  }
  </code></pre>
  
  <p>using command</p>
  
  <pre><code>g++ -std=c++11 -Wall -g  -D__USE_W32_SOCKETS D_WIN32_WINNT=_WIN32_WINNT_WIN7 test.cpp -o test.exe
  </code></pre>
  
  <p>but compile fails. <strong>It looks like posix is being used</strong>.</p>
  
  <p>Any ideas why this fails?</p>
  
  <pre><code>In file included from /usr/include/boost/asio/detail/fd_set_adapter.hpp:22:0,
               from /usr/include/boost/asio/detail/select_reactor.hpp:27,
               from /usr/include/boost/asio/detail/reactor.hpp:29,
               from /usr/include/boost/asio/detail/impl/task_io_service.ipp:24,
               from /usr/include/boost/asio/detail/task_io_service.hpp:198,
               from /usr/include/boost/asio/impl/io_service.hpp:71,
               from /usr/include/boost/asio/io_service.hpp:767,
               from /usr/include/boost/asio/basic_io_object.hpp:19,
               from /usr/include/boost/asio/basic_socket.hpp:20,
               from /usr/include/boost/asio/basic_datagram_socket.hpp:20,
               from /usr/include/boost/asio.hpp:21,
               from appcontrol.cpp:16:
  /usr/include/boost/asio/detail/posix_fd_set_adapter.hpp:82:12: error: 'fd_set' does not name a type
     operator fd_set*()
              ^
  /usr/include/boost/asio/detail/posix_fd_set_adapter.hpp:105:11: error: 'fd_set' does not name a type
     mutable fd_set fd_set_;
             ^
  /usr/include/boost/asio/detail/posix_fd_set_adapter.hpp: In constructor 'boost::asio::detail::posix_fd_set_adapter::posix_fd_set_adapter()':
  /usr/include/boost/asio/detail/posix_fd_set_adapter.hpp:42:14: error: 'fd_set_' was not declared in this scope
      FD_ZERO(&amp;fd_set_);
               ^
  </code></pre>