title: error: use of deleted function boost::shared_mutex::shared_mutex
body: <p>This is really weird. First I didn't know that you can delete functions and second, this happens in external library.</p>
  
  <p>The circumstances of the error are that I'm using QtCreator to build project AND boost all together, without any static libs whatsoever.</p>
  
  <p>The compiler used is <code>gcc</code></p>
  
  <pre><code>myprogram.h:4:7: error: use of deleted function 'boost::shared_mutex::shared_mutex(const boost::shared_mutex&amp;)'
  In file included from ../libs/boost155/boost/thread/lock_guard.hpp:11:0,
                   from ../libs/boost155/boost/thread/pthread/thread_data.hpp:11,
                   from ../libs/boost155/boost/thread/thread_only.hpp:17,
                   from ../libs/boost155/boost/thread/thread.hpp:12,
                   from ../libs/boost155/boost/thread.hpp:13,
                   from myprogram.h:2,
                   from myprogram.cpp:1:
  </code></pre>