title: link error when using boost library on MacOSX
body: <p>I have created a XCode project and I have added "/opt/local/include/boost" to Header Search Path and "/opt/local/lib" to  Library Search Path</p>
  
  <p>But I still have this error:</p>
  
  <pre>
  boost::system::get_generic_category()", referenced from:
     __static_initialization_and_destruction_0(int, int)in main.o
     __static_initialization_and_destruction_0(int, int)in main.o
     __static_initialization_and_destruction_0(int, int)in main.o
  </pre>
  
  <p>And in my /opt/local/lib, I find this (I assume that is Boost.System library):</p>
  
  <pre>
  -rw-r--r--  2 root  admin     80600 Jul 23 16:31 libboost_system-mt.a
  -rwxr-xr-x  2 root  admin     30988 Jul 23 16:30 libboost_system-mt.dylib*
  </pre>
  
  <p>Can you please tell me what am I missing?</p>