text: #ifndef BOOST_THREAD_SHARED_MUTEX_HPP
  #define BOOST_THREAD_SHARED_MUTEX_HPP
  
  //  shared_mutex.hpp
  //
  //  (C) Copyright 2007 Anthony Williams
  //  (C) Copyright 2011-2012 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)
  
  #include <boost/thread/detail/config.hpp>
  #if defined(BOOST_THREAD_PLATFORM_WIN32)
  #if defined(BOOST_THREAD_PROVIDES_GENERIC_SHARED_MUTEX_ON_WIN)
  #include <boost/thread/pthread/shared_mutex.hpp>
  #else
  #include <boost/thread/win32/shared_mutex.hpp>
  #endif
  #elif defined(BOOST_THREAD_PLATFORM_PTHREAD)
  #include <boost/thread/pthread/shared_mutex.hpp>
  #else
  #error "Boost threads unavailable on this platform"
  #endif
  
  #endif
  