title: Hiding C++ symbols with -fvisibility=hidden
body: <p>I have a C++ library with a C API, and I have set the <code>-fvisibility=hidden</code> compiler flag,
  and then I have set  <code>__attribute__ ((visibility ("default")))</code> on C API methods.</p>
  
  <p>However, I still see visible C++ symbols. When I create a debian package for my library,
  I get the following <a href="https://github.com/GrokImageCompression/grok/blob/debian/master/debian/libgrokj2k1.symbols" rel="nofollow noreferrer">symbols file</a></p>
  
  <p>Why are these symbols still visible ?</p>